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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Subwoofer FUD Forum Archive => Topic started by: Nathan Lehouillier on September 05, 2005, 09:55:13 pm

Title: DANLEY Sound Labs TH-115?
Post by: Nathan Lehouillier on September 05, 2005, 09:55:13 pm
I have been looking at the Danley Sound Labs TH- 115 and with the new pic
am quite puzzled. It looks to me that the horn mouth is unusually small and the woofer is mounted right inside it. Now I have not actually seen this box in person
but from the pic and the specs I am very curious. Does anyone know how this
sub stacks up to the LAB? I will be looking at possible 4 of these by Jan. and
will post all findings. Basically I will be using these for small bar shows as a
replacement for my 18" w horns that will be left for outdoor use only.
I'm hoping this sub has a more aggressive sound compared to the lab.
looking at the limited data this would be my conclusion.
Thanks,
Nathan Lehouillier
Kick Drum Sound & Lighting
Title: Ones to Watch
Post by: Wayne Parham on September 05, 2005, 10:16:58 pm

Be sure and watch the Prosound Shootout in October.  There will be several subs tested there.  Danley has been invited, so maybe he'll bring one of those, I don't know.  But I know there will be some good gear there, and it's worth watching.  More details in the ART thread here and the PSW thread here.

Title: Re: DANLEY Sound Labs TH-115?
Post by: Tom Danley on September 06, 2005, 03:38:43 pm
Hi

The TH115 is a very modestly sized bass enclosure, which uses a 15” driver in a new type of low frequency horn I developed called a Tapped Horn.
Your observation about the mouth area being small is correct, the advantage of the Tapped horn is that it allows a significantly smaller horn to be used than normal.
How you ask?
AS you make the horn mouth smaller, one finds ripples in the frequency response, which inversely coincide with peaks and dips in the impedance curve.
These reflect a greatly changing acoustic load on the driver.
With the Tapped Horn, the driver source impedance to the horn is made to change with frequency also, in a way that can largely adapt to the changing horn load, at least over the bass range.  This is done by having both sides of the driver, driving the horn but from different points on its length.
You will notice that even with one TH115, the normal ripple one would expect in a horn that small is not present.
A more extreme case is the PB-12 which has a Teeny Tiny mouth but still lacks the traditional ripple pattern.

So far as the LabSub, it was pretty much as much as I could get out of that size box and cutoff, going as far as seemed safe with driver parameters.
Even now some years later, the Lab 12 driver is one beefy driver.

The only Tapped Horn comparable in size to the Lab sub is the Vortex, also a Tapped horn which is a little smaller (42 by 42 by 22 ½ in).  I couldn’t find the measurements someone sent me of their single Lab @ 1meter but one for one the Vortex would have less ripple and greater sensitivity.
Once you had say 6 Labs (where the mouth is big) then they would be about 50% efficient and would be hard to beat electroacoustically.
Multiple Vortex’s in a 2X2 , 2X3, 3X3 array would have forward directivity due to the frontal area BUT requires a crossover below 90-100 Hz due to the spacing between outlets.
A 2X2 array would have about 10 dB of apparent gain on axis added to the sensitivity mid band in addition to a higher over all efficiency.
We do not have measurements for that case yet however.

In another thread there here is a discussion about spec’s.
The curves on our web site are TEF measurements, taken in a conservative way by driving the box in half space at 100W and at a microphone distance of 10 meters.
This removes the errors present if one measures a large speaker up close at 1 meter and the 10 meter distance is –20DB from 1 Meter but the 100W level is + 20dB from 1 Watt so the result is a conservative  1 Watt equivalent.
These are what anyone else will measure if they do the same test, no magic or BS.

Numbers are for designing so they should be accurate but listening is what really matters, I think you would be impressed with the sensitivity, sound quality, output and weight of the TH115….but how else could I feel ha ha..
Your best bet is to call Mike and see about getting some demo’s, nothing beats first hand comparisons.

Hope that helps

Tom Danley

















Title: Re: DANLEY Sound Labs TH-115?
Post by: Stephen Robertson on September 06, 2005, 04:56:47 pm
Tom Danley wrote on Tue, 06 September 2005 14:38

Hi




The only Tapped Horn comparable in size to the Lab sub is the Vortex, also a Tapped horn which is a little smaller (42 by 42 by 22 ½ in).  

Multiple Vortex’s in a 2X2 , 2X3, 3X3 array would have forward directivity due to the frontal area BUT requires a crossover below 90-100 Hz due to the spacing between outlets.




So Tom, that pic of the Vortex, is that the front of the cabinet? It looks like the access panel on a lab sub.

Does it really weigh 120#s?

What happened to the TH-212

Thanks,
steve

Title: Re: DANLEY Sound Labs TH-115?
Post by: Wayne Parham on September 07, 2005, 04:24:11 am

Very much like a scoop.  Over parts of the frequency range, the front wave and rear wave combine contructively.  Groovy, baby, yeah!

Title: Re: DANLEY Sound Labs TH-115?
Post by: [x] on September 07, 2005, 12:50:03 pm
Tom, may I ask who is currently doing your website?

Your product line is fantastic, but the web page looks like a canned design that DSL just added their own stuff to over the course of a weekend. The personal photo album, while intriguing, is organized in a very unprofessional way. It looks like your personal web site, not the website of a company that actually intends to do any business. EAW's web site doesn't post a bunch of pictures of Kenton Forsythe's personal life, and Community's web site doesn't have a bunch of pictures of Bruze Howze's personal life. Because the DSL website is so lacking in both content and visual impact, Danley Sound Labs will largely need to rely on word-of-mouth for its marketing.
I suggest that you use some of your first profits to hire a good professional design firm to handle your marketing communications. This will be a limiting factor to your success as a company if you don't do something about that web site.

Here is a design sample that I made quite some time ago:
index.php/fa/2435/0/

With the right marketing approach, you could steal quite a bit of the market share of the big guys like EAW, Nexo, and Meyer. I know marketing is a dirty word around here but you need to reach your customers somehow, and word of mouth, while always good to have, is extremely slow. You don't need to avoid marketing period, just avoid making stretched claims in your marketing. But marketing is a necessity of business, and if you want the world to know about the great things your product line is doing, you are going to have to tell them.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Tamas Tako on September 07, 2005, 02:27:22 pm
Tom Danley wrote on Tue, 06 September 2005 21:38

Hi

The TH115 is a very modestly sized bass enclosure, which uses a 15” driver in a new type of low frequency horn I developed called a Tapped Horn.
Your observation about the mouth area being small is correct, the advantage of the Tapped horn is that it allows a significantly smaller horn to be used than normal.
How you ask?
AS you make the horn mouth smaller, one finds ripples in the frequency response, which inversely coincide with peaks and dips in the impedance curve.
These reflect a greatly changing acoustic load on the driver.
With the Tapped Horn, the driver source impedance to the horn is made to change with frequency also, in a way that can largely adapt to the changing horn load, at least over the bass range.  This is done by having both sides of the driver, driving the horn but from different points on its length.
You will notice that even with one TH115, the normal ripple one would expect in a horn that small is not present.
A more extreme case is the PB-12 which has a Teeny Tiny mouth but still lacks the traditional ripple pattern.

So far as the LabSub, it was pretty much as much as I could get out of that size box and cutoff, going as far as seemed safe with driver parameters.
Even now some years later, the Lab 12 driver is one beefy driver.

The only Tapped Horn comparable in size to the Lab sub is the Vortex, also a Tapped horn which is a little smaller (42 by 42 by 22 ½ in).  I couldn’t find the measurements someone sent me of their single Lab @ 1meter but one for one the Vortex would have less ripple and greater sensitivity.
Once you had say 6 Labs (where the mouth is big) then they would be about 50% efficient and would be hard to beat electroacoustically.
Multiple Vortex’s in a 2X2 , 2X3, 3X3 array would have forward directivity due to the frontal area BUT requires a crossover below 90-100 Hz due to the spacing between outlets.
A 2X2 array would have about 10 dB of apparent gain on axis added to the sensitivity mid band in addition to a higher over all efficiency.
We do not have measurements for that case yet however.

In another thread there here is a discussion about spec’s.
The curves on our web site are TEF measurements, taken in a conservative way by driving the box in half space at 100W and at a microphone distance of 10 meters.
This removes the errors present if one measures a large speaker up close at 1 meter and the 10 meter distance is –20DB from 1 Meter but the 100W level is + 20dB from 1 Watt so the result is a conservative  1 Watt equivalent.
These are what anyone else will measure if they do the same test, no magic or BS.

Numbers are for designing so they should be accurate but listening is what really matters, I think you would be impressed with the sensitivity, sound quality, output and weight of the TH115….but how else could I feel ha ha..
Your best bet is to call Mike and see about getting some demo’s, nothing beats first hand comparisons.

Hope that helps

Tom Danley






It is so good to see Tom here back again!
Please Tom, post more on this forum!
I think, we are all interrested for your new products, and your new ideas,how to use them to get the maximum out of them...
For example the Vortex you mentioned has a response graph only for 1 enclosures on your site, however the mentioned 2x2 or even 3x3 setup's sensitivity graphs would be quite interre3sting...

And please again, write here.

Tamas













Title: Re: DANLEY Sound Labs TH-115?
Post by: Ivan Beaver on September 07, 2005, 03:33:40 pm
[quote title=SRaudio wrote on Tue, 06 September 2005 16:56
So Tom, that pic of the Vortex, is that the front of the cabinet? It looks like the access panel on a lab sub.

Does it really weigh 120#s?

What happened to the TH-212

Thanks,
steve

[/quote]
The photo shows the "exit" or as Tom likes to say "Where the sound comes out". That would be the front of the cabinet. There is a grill over that hole (that does not show up on the photo).  It is also the access panel for the speaker. It is fairly heavy because there is a lot of wood inside the cabinet.  It only has the 1 driver, the rest of the weight is the wood.  It has 2 layers and lots of "twisting" going on inside it-hence the name VOrtex.  The working name was the "Twister".

The TH212 was a very early product with several products spun off of it.  The biggest problem with it is how do you move it easily, or in an install-where do you put it?  The performance is fine-it is just the packaging that is an issue.  It was built to test the theory, so it could be measured.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Stephen Robertson on September 07, 2005, 04:09:31 pm
Could the vortex be used in a down firing configuration the way the bdeap did. Or is that still on the list of test yet to happen.

steve
Title: Re: DANLEY Sound Labs TH-115?
Post by: Ivan Beaver on September 07, 2005, 05:29:39 pm
It hasn't been tried in that configuration.  It is designed to be a stand alone sub. As you put several together you will get directivity, which will increase the level. The response if flat to 30Hz (a real -3dB), in a true 1/2 space environmnet.  It was standing alone on the edge of a parking lot facing a field, with no boundaries within 80' or so, and those were behind it.  The bdeap was relying on a extra boundary to get the extra low end.  With the bdeap the way it was loaded gave various results.  If it was down firing with a small air chamber below it, you got a deeper bass, but not as loud.  As this distance increased the low end cutoff got higher, but it got louder. I would ususally use 4-6" off the wall (facing the wall) or floor (downfiring) in most applications.
Title: Re: DANLEY Sound Labs TH-115?
Post by: [x] on September 07, 2005, 06:14:14 pm
Come on, someone's got to agree with me about the web site...

One professional company that does mesmerizing work is DeepBlue. I've seen several of the sites that they've designed for and it is truly fantastic work. You could have them put together a graphics package and create the pages in template form and then you can add the content yourself.

http://www.deepblue.com/

One website DeepBlue did for a smaller operation is the Sentry Siren website. Sentry Siren builds outdoor warning sirens for use in weather and municipal emergencies, but primarily for tornadoes. http://www.sentrysiren.com/
Title: Re: DANLEY multi-reply
Post by: Tom Danley on September 07, 2005, 08:36:42 pm
Hi all

I am really busy, I hope you guys don’t mind if I try to reply to everyone in one writing.

First, Rory, yes the website is some canned software so it is “less cool” looking than ideal.   Web site design is a world I am a blind stranger in however, so I can’t help much other than send a bunch of olden days photos and make thing to put on it..  If you’re a web designer and feel like it, (call first of course) go to Atlanta and show Mike your stuff, who knows he might offer you a job.


Hi Wayne, the th115 does look kind of like a scoop, a concession to cosmetics, the th28, th115 and Vortex all have the “Tap” (location of the “other side” of the driver) near the mouth, while the Tower and several in process do not.  It is as you describe, constructive addition, in effect, the drivers radiator area changes with frequency.

Hi Steve
You know that 120 lb does seem “light”, we will double check that, like Ivan said, there is “wood” inside.
The th-212 was dropped mostly due to it having computer screen disease.
You know, it looked easier to move on the computer screen than made in wood, although it worked fine..  On the Vortex, you are facing the outlet. The funny shape opening, well I can’t think of a funny answer so its because of the shape of the horn passages behind.
Yes, the Vortex could be mounted facing down or another boundary, I have modeled that and it does a similar thing but that configuration has not been tested and confirmed.

Tamas

Yeah that’s another thing on“the big list” of things to do.
The Bdeaps had very significant forward directivity when in a quad, these should be similar due to the identical size.  
AS I recall, the group of 4 Bdeaps measured 97.5 dB midband @ 1W @ 10 meters.
Both the 115 and Vortex in arrays should have (yet to be verified in real life) significant directivity, without processing.
Thanks

Got to run and do some consoling, my daughter’s boy friend just broke up with her tonight. Ahh those fun teen years.
Best to all,

Tom Danley

Title: Re: DANLEY multi-reply
Post by: Wayne Parham on September 07, 2005, 10:11:33 pm

Very interesting.

We're all still hoping you'll come to the Prosound Shootout, or maybe send Mark or Ivan.  If no one can come represent you, perhaps you would like to send a basshorn and we'll put it on the website for you.

We're making every effort to ensure testing is fair, accurate and impartial, and you can help arrange the test conditions if you want.  You were always invited to do that, and still are.

Lots of people are lining up to attend, so much that we're contemplating making the event a two-day deal.  Every one of Fitzmaurice Tuba systems will be there, from the smallest to the largest.  Also there will be my 12 Pi horn, a Bassmaxx model and a JBL bass bin.  Everyone would like to see your participation too.

Title: Re: DANLEY Sound Labs TH-115?
Post by: Paul Valenzuela on September 08, 2005, 02:03:31 am
Come on, someone's got to agree with me about the web site...

I dont post to much, but I think when someone with the recognition and trayectory as Mr. Tom Danley doesn't need fancy marketng.

People who knows his job, are they customers; guys who  knows little about speakers (or nothing) or him, should not even think on buying his work (what's a Ferrari for a farmer?? PS. I was a farmer)

Let's stick to desing and technology and leave marketing to people who really need's marketing.

Yours,
Paul Fdo Valenzuela
Hermosillo, Sonora, Mexico ........ City of the sun
Title: Re: DANLEY Sound Labs TH-115?
Post by: [x] on September 08, 2005, 07:50:37 am
That's all very nice and idealistic, but believe it or not there are still some big decision-makers at live sound companies who do not visit the Live Audio Board, and who could benefit greatly from using Danley Sound Lab products. Sure, word of Danley's reputation will "eventually" get around, but when Tom's investors come around and ask him to show them the money, "eventually" won't really cut it. And I feel the "Ferrari for a farmer" analogy, while quite cleverly worded (kudos), doesn't really fit here. Instead of a ferrari, think about one of those big John Deere tractors with double front and rear tires, compared to one of those little foreign-built Kubota tractors. It's not like better speakers are simply a luxury, for the enjoyment of the owner. Instead, it would give

Tom, I didn't necessarily mean that you would hire _myself_ per se, but some professional company of some type that is located somewhere closer to you (right now I lack the means to fly to Atlanta) to produce a web site with better organization and design, which will catch and hold the attention of visitors. It would be sort of like the templates you are using now, only spiffier, more distinctive, and better organized. You (or someone working for you) would just put in the content yourself (or themselves). Or, you could have the web design firm also deal with updates, but that would be slower than being able to do it yourself. I think that Danley Sound Labs should come up with a logo that will be more recognizable at a distance as well, like EAW and Community. That was the major focus when I was designing my concept logo design. You could show that to whatever professional company you hire and get them to crank out a more spiffy version.

And while I've got Tom's ear, how about a small tapped horn using 8" woofers but with carrying handles for porable use? And, perhaps a speaker using the same coaxial 8" as the SH-100 but in a smaller-format pole-mountable portable version? If you just want to make an existing design fit the bill for the small portable subwoofer, the old version of the TH-28 with the sort of flat profile with the opening in the middle of the front would be nice. Then carrying handles on the ends, or on the rear corners, and putting the SpeakOns on the rear panel, would be all that would be needed for portable use. Or a tapped horn with a 10" driver might also work well for this application, and might be a way to get a less expensive product for this portable product sector. The horn would just sit on its largest side panel (sideways) and make a good wide base for pole-mounting a full-range top speaker. Please try to make your portable full-range top speaker have a list price somewhere under $799, so Danley Sound Labs technology can be more accessable to sound companies. You could also make versions of your SH-50 speaker with ATM flytracks up the sides of the enclosure front, so you could have flyable touring system that would show all those people who think line arrays are the shiznit what's what.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Stephen Robertson on September 08, 2005, 11:08:39 am
I'll jump in and agree with you on the website and marketing in general. Regardless of how good the product is. The reality is that   customers for these products are generally not audio people. Pastors, Worship leaders, Club owners, and rental customers write the checks for this kind of product. The big boys know this and market accordingly. This is why products using 60 year old technology are marketed as revolutionary innovations on glossy full page ads in non audio publications. They are not necessarily trying to sell to "us". Customers who are audio people with a solid understanding of theory and experience with lots of product will be able to judge the product on its merit. But these people are few and far between and they all work for somone. And that someone almost always will always view the product through the lens of the marketing image portrayed by the company.


As far as products I would like to see. A vortex equivalent that can fit under a stage (the reason I ask about the down-fire option). A SH-100 horn mounted in a wedge should be simple to develop. SH-50 type horns in a variety of coverage patterns. And a wide angle down fill box to use with the SH-50.


Steve






 
Title: Re: DANLEY Sound Labs TH-115?
Post by: [x] on September 08, 2005, 01:01:07 pm
Yeah, I really think the side firing form factor is going to end up being awkward when used more than 1 per side. An endfiring horn subwoofer would couple well with more horn subwoofers while not having a large profile. Perhaps a design that looks kind of like the older endfiring TH-28 but with the big single-15 in the mouth instead of two eights would be the most suitable to large-format touring arrays. I also would like to see the old TH-28 come back as a TH-28E Endfiring version. The new TH-28 doesn't have the same sort of versatility that would let it be placed under a low stage. However, the TH-28E should have its inputs on the back of the enclosure and not on the top. At my church, the stage is up on 14-16" risers which would easily fit one or two TH-28 subwoofers underneath. But they probably would not fit the current version of the TH-28. The trend in designs like these is really towards the endfiring boxes. The Twister is an interesting experiment, but the real moneymaker would be in a version of the Vortex that is endfiring.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Randy Pence on September 14, 2005, 10:18:14 am
Would the infrabass from funktion one also fit into this tapped horn catagory?  It is designed to play from from 20-90, but in practice is often limted in it high freq and augmented with the f218 playing hte higher sub material.  Tony Andrews has also always been a horn guy and his webpage marketing claims a completely new loading design.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Walt de Jong on September 14, 2005, 12:46:27 pm
No,

The Funktion One Infrabass is a fourth order bandpass. It has two closed chamers for the 18" woofers. The middle chamber works both as a chamber as port.

In all Funktion One products the back of the driver is contained in a closed volume. Off course there is a reason to do that.

Best regards,

Walt
Title: Re: DANLEY Sound Labs TH-115?
Post by: Michael_Elliston¶ on September 14, 2005, 03:06:15 pm
Walt wrote on Thu, 15 September 2005 04:46

No,

The Funktion One Infrabass is a fourth order bandpass. It has two closed chamers for the 18" woofers. The middle chamber works both as a chamber as port.

In all Funktion One products the back of the driver is contained in a closed volume. Off course there is a reason to do that.

Best regards,

Walt

BP4 lends itself to average sensitivity,how is the quoted sensitivity achieved ?

Secondly,why do they attach 'horn' to anything that is remotely loud! It could ruin the name of the horn by using highly resonant systems like tuned pipes/BP.

Title: Re: DANLEY Sound Labs TH-115?
Post by: Johan Rademakers on September 14, 2005, 05:41:43 pm
Quote:

BP4 lends itself to average sensitivity

With BP 4th (and 6th) order you can choose between an average sensitivity with large bandwith and high sensitivity with a small bandwith. It probably uses two costumdrivers with low fs and high Vas. With the frequency band optimised between 30 and 60 Hz.

Still it's quite much.

Mvg Johan
Title: Re: DANLEY Sound Labs TH-115?
Post by: Michael_Elliston¶ on September 14, 2005, 06:32:34 pm
Johan wrote on Thu, 15 September 2005 09:41

Quote:

BP4 lends itself to average sensitivity

With BP 4th (and 6th) order you can choose between an average sensitivity with large bandwith and high sensitivity with a small bandwith. It probably uses two costumdrivers with low fs and high Vas. With the frequency band optimised between 30 and 60 Hz.

Still it's quite much.

Mvg Johan

Hi Johan.
It is an interesting idea to use low Fs inefficient units on a resonant system to increase their sensitivity again Wink




Title: Re: DANLEY Sound Labs TH-115?
Post by: Stephen Robertson on September 14, 2005, 06:33:11 pm
I pose the following questions out of ignorance rather than doubt. Smile

Does the Tapped horn really meet the criteria for a horn either? Especially in the case of the PB-12 and the vortex where the mouth is so small. To answer my own question I assume it is because the TH does serve as an acoustic transformer even if the mouth is too small to have pattern control?

How does the TH differ from a transmission line?

How does the tapped horn avoid the problem the old scoops had with the rear wave arriving late and causing cancellations?

Is the TH truly a new alignment or a method of optimizing an old one?

With the sensitivity being relatively high on most of the models it seems harmonic distortion should be much lower than a front loaded design, but with the drivers exposed does that mean more distortion relative to a traditional bent bass horn where the drivers are buried behind several curves?

How does the TH avoid excessive group delay and messy transient response?

How much propagation delay is exhibited by the various TH models?

Some of the spec sheets include the statement:

"Low frequency pattern control extending well below 100Hz is achieved by adding a second subwoofer. Unlike many designs on the market today the TH achieves this control without compromising output or additional signal processing expense."


Is this increase simply because of more mouth and surface area or is there an additional trick?

Why is the sky blue?

Where do babies come from?

Why do we drive on parkways and park........

Thanks, Smile
Stephen Robertson
Title: Re: DANLEY Sound Labs TH-115?
Post by: Johan Rademakers on September 15, 2005, 02:05:39 am
I found it really difficult to simulate a 4th order bandpass that with the use of 18" would have the Frc from the rearchamber, low enough to get to a substantial 30 Hz (not even mention 20 Hz). Unless the Fs is lowered on some specific units to get the Frc low enough (or the backchamber most be at least double the size as I took it, as you know efficiency drops radically below Fs in general).
There are some low Fs units out there that still are efficient (like PD 21), even tho you wouldn't expect it because Fs seems substantial in the next formula.

n0= (Fs^3 x Vas)/Qes. That's of course why it should have higher Vas and (very) low Qes to compensate, as well as high Sd, BL etc. Couldn't think of that excisting already, so should be custom. Void V18 1000 and SD-18 do both excellent jobs in X1, while Fs is still relatively low for such efficiency.

So it might sound crazy but it might just work.

Mvg Johan
Title: Re: DANLEY Sound Labs TH-115?
Post by: Randy Pence on September 15, 2005, 06:00:08 am
F1 says they do a bit of customizing with the drivers to fit the application they want, but i only know and udnerstand enough about this depth to sit back and learn.

nice thread so far.  Interesting point about what is classified as a horn.

oh, and maybe since im not a church guy I find the danley website okay.  A bit more about the sonic boom stuff would be cool.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Michael_Elliston¶ on September 15, 2005, 10:38:53 pm
I agree. Or you could use ACE BASS to modify the drivers parameters by electrical means!
Title: TH 115 Sub-Driver looks like an RCF??
Post by: Steve Shafer on September 16, 2005, 03:30:40 pm
Anyone know who is supplying the drivers?  Just wondering if this is an RCF driver.

Steve S
Title: Re: TH 115 Sub-Driver looks like an RCF??
Post by: Ivan Beaver on September 16, 2005, 03:50:26 pm
There are various manufacturers used in different cabinets. No RCF anywhere.  The one in the TH115 is B&C.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Marcel Groen on September 17, 2005, 10:47:58 am
Best diy-ers,

Since the year 2000 i became "silent" reader of the Lab subwoofer forum. Till now i haven`t post a message on this forum, but i am a happy owner of the Labsubs.
Since Tom Danley brings out the tapped horn i became very curious off these type`s of subwoofers. The most interesting part for me is or these horn could accurately be modeled from a scratch and would these horns give the "free" sound like a vented/closed sub does?

Marcel

Cool Adicted to bass Cool
 
Title: Re: DANLEY Sound Labs TH-115?
Post by: Phil Pope on September 19, 2005, 04:03:48 pm
I have been trying to figure out what is happening inside the tapped horn designs for a while.  On a few of the pictures you can see either where one side of the driver is mounted near the mouth or where there is an access panel which presumably gives access to one or other side of the driver.  I can't see any relation between the distance of the back of the driver from the mouth and the frequency response or impedance chart. In some of the designs the back side of the driver is so near the mouth it can't be horn loaded and its output must be insignificant compared to what is coming down the horn.

I have seen a design where the back chamber has a port that enters the horn further back than the driver

http://www.audioasylum.com/forums/hug/messages/87962.html

but Tom Danley replied to that thread suggesting that it is difficult to load a vent with a horn because of the frequency dependent loading of a horn.  Perhaps you could use several ports all loading over a very small frequency range.

Perhaps the tapped horn uses several small apertures to form the horn throat.  I'm not sure if it is viable but could the size of the apertures be used to offset the low impedance presented by the horn at certain frequencies?

Phil
Title: Re: DANLEY Sound Labs TH-115?
Post by: Marcel Groen on September 20, 2005, 03:46:49 pm
Hi snowflake,

I also don`t know how to get that extra loading under the passband off the horn. I you look to the impedance chart of the TH115 i think that the first two resonantpeaks from the right are those from the real horn. The one on the left must have a relationship with the pressure that comes from the front of the speaker. The pathlengt of the horn must be calculated in otherwise you could not get the resonantpeak at the point you wanted to be if you model this type of loudspeaker.
But if you calculated it with only the speed of sound, like you mentioned, you could not see a relationship between the pressure on the back of the driver and the pressures that comes from the front. Now i am not to familiar with phase, but it could be that some delay is accounted in that is caused by phaseshifts. I don`t know what the phase will do under the passband of the horn. And can real acoustic phase be modeled with a equivalent circuit(Leach).
At the time the speaker is moving backwards there must be pressure on the back of the diagram, at least i think so. When the full pressure(from the front) must come on the back of the driver i don`t, maybe at the time when it`s going back or maybe at his neutral position.
This pressure could be calculated like a sort of back emf in the acoustic circuit, just like the acoustic/mechanic circuit introduce the back emf to electrical circuit.
Maybe i am totally on the wrong road, i am just trying to understand it with logical explanations.

Marcel    

Ps. my englisch is not very good.  
Title: Re: DANLEY Sound Labs TH-115?
Post by: Michael_Elliston¶ on September 20, 2005, 10:01:56 pm
snowflake wrote on Tue, 20 September 2005 08:03

I have been trying to figure out what is happening inside the tapped horn designs for a while.  On a few of the pictures you can see either where one side of the driver is mounted near the mouth or where there is an access panel which presumably gives access to one or other side of the driver.  I can't see any relation between the distance of the back of the driver from the mouth and the frequency response or impedance chart. In some of the designs the back side of the driver is so near the mouth it can't be horn loaded and its output must be insignificant compared to what is coming down the horn.

I have seen a design where the back chamber has a port that enters the horn further back than the driver

http://www.audioasylum.com/forums/hug/messages/87962.html

but Tom Danley replied to that thread suggesting that it is difficult to load a vent with a horn because of the frequency dependent loading of a horn.  Perhaps you could use several ports all loading over a very small frequency range.

Perhaps the tapped horn uses several small apertures to form the horn throat.  I'm not sure if it is viable but could the size of the apertures be used to offset the low impedance presented by the horn at certain frequencies?

Phil

Hi Phil,Well I  dont know if it applies here,but when a reflex system has several different ports,they sum to one 'inbetween port'

Im really interested in this stuff too. I expect some FEA would help.

Mike.e
Title: Re: DANLEY Sound Labs TH-115?
Post by: Tom Danley on September 21, 2005, 01:16:13 pm
Hi guys

A bunch of people asked questions, I will try to answer.

I don’t think it would be fun or fair to just explain how to build a Tapped horn although Walt seems very close.
Rather, what I can do is to mention a few “clues” or things, which lead to the approach.

When working with the Unity and later Synergy horns, it was clear that the acoustic passageway called a horn could be driven from a location other than at the “small end” with only a few differences in operation, all of which can be modeled.

The bass reflex approach provides a phase inversion (at resonance) which allows the rear radiation to be additive with the front.
This approach depends heavily on a high Qb in order to have a high Q in operation, horn loading a port produces a significant acoustic load which greatly alters the Qb.
Bottom line is the port stops working properly if significantly loaded by the horn.

The real problem with a horn that is too small is that the radiation load presented to the driver changes too much vs frequency, in a perfect horn (the kind assumed in horn theory) the radiation resistance is constant.
Peaks in the output are normally associated with dips in the impedance which causes “more” power to be delivered, producing the peaks.

The Tapped horn approach can be smaller because at the low cutoff, the drivers appears to have a smaller radiating area (but the same motor), which raises the electrical impedance, lowering the peak.
Above the low cutoff peak, the driver can appear to have as much as twice its original radiator area (still on the same motor) which raises the dip by having a greater area / load.

The idea in the patent application is that the drivers acoustic source impedance tracks the horns acoustic load impedance (when everything is right) which results in a MUCH flatter response and greater efficiency than a conventionally driven horn the same size could produce.


One cool benefit of the approach is seen when one compares the group delay of a Vented box and Tapped horn with an identical low cutoff.
The PB-12 tower for example has a measured group delay which hovers around “zero” down to about 30 Hz.  
A vented box with the same low cutoff would already have about 10 –12 ms GD at 30 Hz.     One can picture the effect of GD more clearly when you recall that this is like moving your speaker to the rear in time at a rate of 13.5 inches per millisecond of delay.

The other effect of the Tapped horn can be realized when you consider that alone, the driver in the Tower has a sensitivity of about 88 dB 1 W while it is a minimum of 95 dB 1W 1M when in the Tapped horn.

If you guys are inclined to and are near Atlanta, call the shop and go get a demo and see what you think.
Best,

Tom Danley

Danley Sound Labs

Stephan,  So far as why is the Sky Blue?, I would guess it has something to do with the fact that liquid oxygen is also sky blue.
Liquid oxygen has gotten a bad rap too, look what you can do with it.
Hungry? Fire up the bbq. Yumm.

http://www.doeblitz.net/ghg/










Title: Re: DANLEY Sound Labs TH-115?
Post by: Phil Pope on September 21, 2005, 01:51:51 pm
I'm still struggling on the tapped horn but I do know why the sky is blue.  Dust in the atmoshphere scatters the shorter blue wavelengths in sunlight to a greater degree than the longer red wavelengths.

Phil
Title: Re: DANLEY Sound Labs TH-115?
Post by: Tom Danley on September 21, 2005, 02:24:22 pm
Hi
True, but the link is more fun than talking about Rayleigh scattering.
Cheers,

Tom
Title: Re: DANLEY Sound Labs TH-115?
Post by: Timber_MG on September 22, 2005, 02:01:31 am
Is it usefull to look at only the m/nodal behaviour of a pipe fired into one end with a rear chamber "tapping" into this pipe (tapered or not) at a position/positions conducive to your requirements? The "tap" if caught at a pressure maximum would act like a flute and dampen an undesired mode and likewise for the driver's relative poition to the closed end of this pipe and one has to go and position the driver and "tap"in a geometrically fortunate position?

The braodband dampening would be similar to an open tranmission line due to the signifficant differene in arrival time of the rear-wave?
Title: Re: DANLEY Sound Labs TH-115?
Post by: Walt de Jong on September 22, 2005, 12:50:34 pm
Hello,

I think it is quite useful to use the (one dimensional) wave equation to understand the principle behind tapped horn:

dp^2/dt^2=c^2 x dp^2/dx^4

With c=speed of sound (this wave equation can be found by solving the mass, impulse and energy balance equations for a small control volume of air in the horn)

The most easy way to solve this by assuming a solution in the form:

P(x,t)=X(x) x T(t)

By using the correct boundary values you will find that X(x) describes the modeshapes in the horn. T(t) gives the timeresponse. For a non-constant cross-sectional area solving this partial differential equation is not easy but it can be done. In fact the principle of 'nodes' in a transmissionline is a result from solving the wave equation. I think most people don't realise this. If you know whats behind the obvious (logical) theory of nodes it much more easy to study new principles such as the tapped horn.

Best regards,

Walt
Title: Re: DANLEY Sound Labs TH-115?
Post by: drewgandy on September 27, 2005, 11:49:35 pm
Tom Danley wrote on Wed, 21 September 2005 12:16

Hi guys

The PB-12 tower for example has a measured group delay which hovers around “zero” down to about 30 Hz.  
A vented box with the same low cutoff would already have about 10 –12 ms GD at 30 Hz.     One can picture the effect of GD more clearly when you recall that this is like moving your speaker to the rear in time at a rate of 13.5 inches per millisecond of delay.












Perhap I'm not fluent enough in group delay but I don't understand how it can "hover around zero" when measured outside the enclosure.  Isn't there some delay at least based on the distance of the driver from the mouth?  
Title: Re: DANLEY Sound Labs TH-115?
Post by: Mark Seaton on September 28, 2005, 01:10:37 pm
chmed wrote on Tue, 27 September 2005 22:49

 
Perhap I'm not fluent enough in group delay but I don't understand how it can "hover around zero" when measured outside the enclosure.  Isn't there some delay at least based on the distance of the driver from the mouth?  


Might it make more sense if it was stated as "was pretty much constant" through the stated range?  

Most measurement systems allow you to define some t0 to get a more useful view of the data, and in some cases, to make the measurement possible at all.  Effectvely you are just removing the time of flight, or fixed delays in the system.  In most LF systems that time of flight is greater than the physical distance from speaker to mic, and even more so in most bass horns.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Tom Danley on September 28, 2005, 01:43:59 pm
Hi guys

Mark answered the question but I can give a bit more explanation.
Group delay began as a descriptor of the difference between the delay at one frequency compared to another.  
The fixed delay component,  related to time of flight and driver internal delay is not part of Group Delay.
As a result, a drivers GD is unchanged by changing the mic to speaker distance.
While a horn can have a larger fixed delay (due to the additional path length), they can also have less group delay than a direct radiator / vented system, as in the PB-12 Tapped horn.

The part about GD which may not be obvious is that all filters have group delay too, not just a speaker. In fact, any normal filter than changes a signal’s amplitude, also produces GD.

Cheers,

Tom Danley



Title: Re: DANLEY Sound Labs TH-115?
Post by: Antone Atmarama Bajor on September 29, 2005, 01:59:42 pm
And those filter group delays are always negative.  Never positive.  Unless you live in some alternate dimension or you pre-delay everything and digitally treat it.  But then everything is later.

Sum-
Title: Re: DANLEY Sound Labs TH-115?
Post by: Johan Rademakers on September 29, 2005, 02:10:10 pm
And the higher the rolloff, the higher the groupdelay.

Wkr Johan
Title: Re: DANLEY Sound Labs TH-115?
Post by: Marcel Groen on October 06, 2005, 03:04:30 pm
Hello,

The clues that Tom gave us about the tapped horn are very usefull. I never looked it that way. From the post`s that Tom and Mark placed in the past about, aspecial the one`s of the unity horns, i learned a lot about phase/time issues, still i have questions about this most important subject. The textbooks i have don`t give me the answers so maybe you guys could fill in.

Correct me if i'am wrong.
I am totally confinced that a speaker can only produces the exact same waveshape as the signal you supply it if you have absolute zero phase and a flat amplitude respons. Other words; the position of the speaker is exactly the same as the "point" is in the signal, so no delay.

The time delay between the supplied signal and the time that you "catched" the sound with your mic consist of three things:
- Time of flight (no frequency depending)
- Group delay (frequency depending and can be calculated out
              the equivalent circuit)
- The internal delay of the speaker itself.

This last delay is my biggest problem when i am trying to design the "perfect" speaker. I think this delay is the difference in measuring a speaker with a TEF machine (conform TDS) and most of the other programms that don`t measuring the absolute acoustic phase. Is this delay frequency depending or is it a constant delay? And what can a speaker tell us about it if we looking to his parameters or it construction?

Most of the diy-ers can`t afford it to buy something like the TEF machine, but what can be done to make the ideal speaker? And how far must be go, if we talking about the perfect speaker. For example; must the phase delay of a mic. also be counted in when measuring a speaker?
Ps.: with the ideal speaker i mean it`s going to act like the way you wanted to act.

Well i have to go.

Cheers,
Marcel




   
Title: Re: DANLEY Sound Labs TH-115?
Post by: brian frost on October 07, 2005, 01:04:47 am
...just bought 4 th115s on reccomendation of my good friend chris van duker of ruckuslab.com

first show w/ them is october 15th, will post pictures, comments after Wink
Title: Re: DANLEY Sound Labs TH-115?
Post by: [x] on October 07, 2005, 02:59:49 am
Where do you get them from? I have never seen them anywhere for sale on a good site like http://www.NorthernSound.com that deals in the really good stuff.

In your description of the Electro Voice mains that you have, those drivers are not "sub" drivers but 'woofers' or 'midbass'. Also, when you add the Danley horn subs, make sure to mention that they are Danley TH-115 Tapped Bass Horn Subwoofers.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Ivan Beaver on October 07, 2005, 09:09:03 pm
[quote title=Rory Buszka wrote on Fri, 07 October 2005 02:59]Where do you get them from? I have never seen them anywhere for sale--- quote]

He got them directly from Danley Sound labs.  Just as anybody can.
Title: Re: DANLEY Sound Labs TH-115?
Post by: brian frost on October 08, 2005, 02:00:51 am
yah, ordered directly from danleysoundlabs.com. tho im worried about them making it to sf in time for my oct15th gig , ugh.

good lookin on the woofer/sub description. site needs to be updated like MAD! haven't done so since summer... soooo many changes since then.

anyway, i bookmarked this forum, so you might see me posting more.

regards,
brian
Title: Re: DANLEY Sound Labs TH-115?
Post by: Mike Hedden on October 08, 2005, 01:03:39 pm
We at Danley Sound Labs are developing a new website which will reflect the world beating products we are producing.  That being said the existing site has been updated multiple times even within the last month. Examples being, SH-50 with measured data, the TH-Vortex with measured data, and all new product pictures on the downloadable .pdf's.  
As to the question of where to buy, let me make it clear Danley Sound Labs is developing a dealer network which will eventually handle all sales. Being a new company our distribution is not highly developed and sales inquiries are handled in house.  Please understand though that if you are an end user Danley will sell to you only at Pro User Net.  
Title: Re: DANLEY Sound Labs TH-115?
Post by: Gareth James on November 15, 2005, 11:17:07 am
Been thinking about this tapped horn malarky...

Tom said that the high Q loading a port stops it from working properly in this instance and I read on a couple of sites about this karlson slot loading stuff affecting a wider bandwidth by varying its loading over frequency.

Its something to do with a exponential or hypex curve cut out of a baffle in front of a driver with a ported chamber and slots and other stuff... basically im not sure how that all comes together as its very hard to find any decent info explaining it.

It seems pretty easy to simulate an "ideal" horn in mcbean, but that assumes that both entry points are receiving the same signal. Which got me thinking, would 2 drivers, each loaded at the 2 separate points have the same effect or any gains?

Or would that just defeat the object of extra efficiency from a single driver... im confused again
Title: Re: DANLEY Sound Labs TH-115?
Post by: Phil Pope on November 17, 2005, 08:38:10 am
have you found this page

http://home.planet.nl/~ulfman/artic.htm

My first thought about the K coupler is that the principle could be applied to an undersized horn mouth to reduce ripple caused by reflections.  Fairly sure this is not what is happening in the tapped horn designs though as it would be visible.  Do you think it might be possible that the horn throat is shaped to give frequency dependant loading?

I think the tapped horn uses Helmholtz cavities on the throat chamber or down the length of the horn to smooth out the peaks that would otherwise result from an undersized horn mouth.  Not sure how to model this so I might try drilling some holes in one of my Labhorns and attach some cavities to the outside to see what it does to the response.
Title: Re: DANLEY Sound Labs TH-115?
Post by: Antone Atmarama Bajor on November 17, 2005, 12:41:52 pm
     Does the Karlson design actually help improve sound quality.  It looks like it was able to improve impedance a little.  I noticed Ivan Beaver Had a few of those in his sound system back a few year ago.  Anyone take any sweeps of those things???

Antone-
Title: Re: DANLEY Sound Labs TH-115?
Post by: Gareth James on November 17, 2005, 06:43:35 pm
I'm not sure about the karlson coupler, my thought was that it was somehow integrated into the throat of the horn...

Phil, I'm pretty certain the shape of the throat is the key to this riddle. I was looking at some simulations on a webpage about horn theory and thought a particular sim showing a narrowing and widening of a section causing a ripple in impedance might be along the right lines.

Maybe its like a tuned vent except the varying cross-sectional area loads a wider bandwidth. Maybe I'm completely off-track, i'm not sure!

Anton, i've not been able to find much on the karlson coupler and a lot of comments have been negative to its sound quality although given the time period in which it originally emerged i don't think its reliable evidence. Still seems like an interesting idea though, i'd love to see a more in depth description of how it actually works and what is loading what!!
Title: Re: DANLEY Sound Labs TH-115?
Post by: Craig Leerman on November 18, 2005, 03:26:28 am
Quote:

 Does the Karlson design actually help improve sound quality. It looks like it was able to improve impedance a little. I noticed Ivan Beaver Had a few of those in his sound system back a few year ago. Anyone take any sweeps of those things???


karlson cabs were designed as FULL RANGE home stereo cabinets, not really as sub or bass boxes. They originally had 12" CoAx or Full range speakers in them. Many folks started to use them as bass speakers because they had a pretty smooth response in the low end.  


If memory serves me correctly, Ivan had Maryland Sound "Clams" in his rig.  These were a slightly changed version of a Karlson cab, used as subwoofers. The Clams used a 15" speaker instead of the original Karlson 12, and were designed to be used as Bass or Sub cabs, not as full range cabs. A single was basically a 15" version of a karlson (but some of the dimensions were changed slightly). A Double Clam was basically 2 karlsons in a single box. A QUAD CLAM was 4 Karlson in a single box.

I had 2 doubles and 2 Quads for a while, but never liked moving them around. They were very heavy, especially since mine were  fiberglassed, and loaded with Gauss speakers! Back then, my version of "SWEEPING a cabinet"  was dusting them off with a broom before a gig! I'm not sure what they would look like on a scope, but they do sound pretty good.

Dave Smith of MSI was the guy who really liked the Karlsons. He had a pair of 12" on his home stereo, and 15" versions on his own PA. I liked the sound of his home stereo with 12" coaxials loaded in them. I've also heard a pair of 15" karlsons loaded with Tannoy coaxials. They sounded great!.  My buddy Sheldon still uses a single MSI Karlson in his livingroom corner as a subwoofer under his Tannoys.

Craig
Title: Re: Karlson Coupler
Post by: Antone Atmarama Bajor on November 18, 2005, 02:18:38 pm
     Yeah its interesting looking,  It looks like the cross section of a exponential horn stuck in front of a speaker.  I just wonder how effectively it actually loads the driver.

    My father was telling me about another company that was making compression driver lenses with a similar slot expansion in it.

    Hmmm I wonder if his concept was actually as valid as he thought.

Antone-  
Title: Re: Karlson Coupler
Post by: Ivan Beaver on November 18, 2005, 07:52:50 pm
Antone Atmarama Bajor wrote on Fri, 18 November 2005 14:18

   
    My father was telling me about another company that was making compression driver lenses with a similar slot expansion in it.

   
Antone-  

It was called "The tube" and came out in the late 70's.  It was a horn driver with "the Tube" attached to it and it faced straight up.  The tube was like a plane wave tube with a slot "looked like the carlson" cut into it.  I think they didn't take off because of the lack of sensitivity.  I only heard them once in a very small room with a lunatic guitar player.  I don't remember how they sounded-the show caught my attention.
Title: Re: Karlson Coupler
Post by: Too Tall (Curtis H. List) on November 19, 2005, 09:41:24 am
Ivan Beaver wrote on Fri, 18 November 2005 19:52

Antone Atmarama Bajor wrote on Fri, 18 November 2005 14:18

   
    My father was telling me about another company that was making compression driver lenses with a similar slot expansion in it.

   
Antone-  

It was called "The tube" and came out in the late 70's.  It was a horn driver with "the Tube" attached to it and it faced straight up.  The tube was like a plane wave tube with a slot "looked like the carlson" cut into it.  I think they didn't take off because of the lack of sensitivity.  I only heard them once in a very small room with a lunatic guitar player.  I don't remember how they sounded-the show caught my attention.




The Tube.
Wow, it’s been a while since I thought of them. I’m surprised Al Limberg didn’t post because he had a set. I heard them used outdoor.

They were mounted on a set of Gauss HF-4000 2” I believe, but I could be wrong.

They were used in a 2-way system with a set of Community Leviathans (dual 15” on a straight horn). So you had these big fiberglass horn loaded dual 15” enclosures with a compression driver laying on its back on top and a short tube attached pointing straight up.

As I recall there was a cut on top at an angle.

The most memorable characteristic was they had almost no vertical dispersion.
Title: Re: Karlson Coupler
Post by: Al Limberg on November 19, 2005, 10:20:04 am
Sometimes things are just better forgotten lol.  Actually, they only offered a 1" version at the time we had ours so they were mounted to a pair of Emilar EA-175 drivers. That was the driver they allegedly used to test and develop the 'tube' so the facceplate of the tube was such that when mounted to the 175 it sat at the proper angle.  It sounded pretty good (keeping in mind TT's reference to very narrow vertical dispersion).  There was certainly no characteristic 'honk'  but there was definitely a drop off in efficiency.  Outdoors the wind just carried it away, more so than a more typical horn flare. The part that turned us off to them the most was the fact that they claimed to have used Emilar's test facilities as well as their drivers in the development stage and pretty much claimed endorsements from some of the Emilar folks - IIRC - Elgis Renkus included.   Since we were an Emilar dealer at the time, we called them to discuss their views.  At that point, no one there would admit to any knowledge of the product or any such testing.  .....things that make you go hmmmmm....


Al
Title: Re: Karlson Coupler
Post by: Iain_Macdonald on November 19, 2005, 07:42:37 pm
Hi all.

Now I feeling really old. My late friend Bill Kelsey used the Tube in his C System design for TFA ElectroSound here in the UK in the late 70's/early 80's. It was a 2 box system, bass and mid + Tubes. The bass had 4 x 15 reflex loaded. The top box (same size as bass) had 4x12ins and 4 Karlson Tubes with 1 inch compression drivers. The tubes were arranged alongside the 12's, vertically in two pairs with the tube ends in each pair touching at something like a 45 deg angle. The idea was to have a vertical line of bass and a vertical line of mid/hi. Yes, a line array in 1980! To me, when set up properly, it was the most hi-fi system that I have ever heard until my experience with planar/ribbon hf systems. Of course TFA had people like Ted Nugent as customers, so volume not Hi Fi was the order of the day. The only problem as I recall, was that it used EV drivers, which at the time were not the power monsters we have today. Also people would insist on stacking mid/hf cabs side by side. The dispersion of the tubes was about 100 degrees, so you can imagine what the comb filtering was like. Had to be heard to believed. Just ask Mick Whelan (EV). In the mid 80's I worked with Bill on developing a 2inch tube, but we had insufficient funds to go anywhere. Just like the compressed air powered bass cab and our early line array. A familiar tale to many, I guess.

Iain.
Title: Re: Karlson Coupler
Post by: RobertOziemkowski on November 22, 2005, 05:19:41 pm
Iain Macdonald wrote on Sun, 20 November 2005 00:42

Hi all.

Now I feeling really old. My late friend Bill Kelsey used the Tube in his C System design for TFA ElectroSound here in the UK in the late 70's/early 80's. It was a 2 box system, bass and mid + Tubes. The bass had 4 x 15 reflex loaded. The top box (same size as bass) had 4x12ins and 4 Karlson Tubes with 1 inch compression drivers. The tubes were arranged alongside the 12's, vertically in two pairs with the tube ends in each pair touching at something like a 45 deg angle. The idea was to have a vertical line of bass and a vertical line of mid/hi. Yes, a line array in 1980! To me, when set up properly, it was the most hi-fi system that I have ever heard until my experience with planar/ribbon hf systems. Of course TFA had people like Ted Nugent as customers, so volume not Hi Fi was the order of the day. The only problem as I recall, was that it used EV drivers, which at the time were not the power monsters we have today. Also people would insist on stacking mid/hf cabs side by side. The dispersion of the tubes was about 100 degrees, so you can imagine what the comb filtering was like. Had to be heard to believed. Just ask Mick Whelan (EV). In the mid 80's I worked with Bill on developing a 2inch tube, but we had insufficient funds to go anywhere. Just like the compressed air powered bass cab and our early line array. A familiar tale to many, I guess.

Iain.


Still have my pair which I used with Altec 808Bs. As I recall, they sound fine when I'd use them with a sm/med club system above 2482s. Better than the (stolen) slots others used. Rolling Eyes
Title: Re: Karlson Coupler
Post by: TrevorMilburn on November 22, 2005, 05:22:10 pm
Iain, you think you're feeling old. I knew I had seen and also read about the TFA Electrosound system in the late 80s/early 90s, but have not heard hide nor hair about it since and thought it was my imagination playing tricks. If I remember correctly, the system was also used by Elvis Costello at the Royal Albert Hall and was given (absolutely correctly in my opinion) rave reviews for the sound quality. The whole system was, if I remember correctly, driven by BGW amps for low and mid, and I have a feeling that Quad 405s may have been used for high end. Didn't have the chance to move around the RHA but from my ground floor seat, it sounded great - certainly not like any of the then prevalent systems (Martin etc).

Regards,

Trevor
(ex Big Trev - frequent poster to the board in the late 90s)
Title: Re: Karlson Coupler
Post by: Tom Danley on November 22, 2005, 10:48:20 pm
Hi Iain

I remember the “Tubes” but never understood how they worked.
Phil Pope’s post above had a link,  at that site I found some pictures of the tubes and Karlson coupler, called a Khybo or something here.
Like the tube, the karlson coupler is an intriguing arrangement.  One can find configurations of radio antenna’s that remind one of the Karlson, yet acoustically, my gut reaction is that he was on to something but not quite all the way there.  
I had fully shelved the concept mentally until the last few years when a DIY’r named Freddyi kept posting links and photo’s and occasional measurements of them.
Now its in the “more of an unknown quantity” box for me, but like an antenna, I am sure the acoustical geometry / sizes are the key to making one truly broad band if that is possible.

Iain, I don’t know if you did Ted’s sound in the USA a bit earlier but in 1972 or1973,  I was a bass player in a band that warmed up for Ted N. concert.  
It was kind of funny, maybe that’s not exactly the right word.
I worked at a small speaker company called Steamer Sound at the time, for the gig, I borrowed every working speaker we had and the PA system we had on hand.
Anyway with all the boxes, we were able to fill the stage edge to edge with   4X12 Steamer boxes 2 high and we had an “out door” sized PA on the sides (2X12 80Hz horns and a number of big Altec multi-cells and 511’s. That was powered (mostly) with home built 200W Tube amplifiers based on the Sunn 2000S (and dynaco) output stage.
It was great fun and a great gig for the band, the best part was a standing ovation.  The next best part was Ted’s brother (I think it was) asked if they could use our PA, for me, that was just as cool as the ovation.
Pretty funny, it took every person we could get with Van’s and station Wagons to haul all the stuff,
“AAHHH,  we hit the big time”.  

Well, I still build speakers anyway.

Here are some of those Tubes and such

http://home.planet.nl/~ulfman/images/soundl12.jpg

http://home.planet.nl/~ulfman/images/soundl3.jpg

http://home.planet.nl/~ulfman/images/soundl4.jpg

Nostalgia lamp off, its getting too smoky in here.
Best regards,

Tom Danley

Danley Sound Labs
Title: Re: Karlson Coupler
Post by: Iain_Macdonald on November 23, 2005, 02:58:31 pm
Trevor,

I seem to remember that the system was sold to people who had a connection with Paul Weller post Jam. Supposedly they changed the tubes for regular horns. I do remember Bill showing me Quads on the HF. (I didn't work for them, just introduced by friends. "Hey Iain went to college, and he knows how to use a scope. Oh, better meet Bill then") The system was reviewed in a number of magazines.

Iain.
Title: Re: Karlson Coupler
Post by: Iain_Macdonald on November 23, 2005, 03:43:33 pm
Tom,

The Tube seems to me, to simply be, a 'broadband' resonating tube with a variable termination. Have a look at the Patent documents they give some insight to his thinking.

No thanks. I didn't do sound for Ted. At that time I was still going to college. Even then I wanted to preserve my hearing. It was stupidly loud. Like enough to cause your eardrum to flutter. His FOH was a crazy American, who publicly claimed, that he could kill the audience by moving a few faders. Ho Hum.. Communication was reputed to be, by line of sight.


Iain
Title: Re: DANLEY Sound Labs TH-115?
Post by: Freddy Ireson on November 23, 2005, 07:56:01 pm
Hi guys

here's a bit of rough diy K-stuff - will have to gather up links to plots and gather data on Transylvania's Tube when weather permits.

does anyone here have info on K-stuff not seen at Ulfman's? - or diy Karlson coupler data to share?

a few K-tubes - LOL

http://home.earthlink.net/~buddhaboy2/tw.jpg

a long/meadering post on a crude/small bass coupler with added air-mass cavity on its front chamber - warning - a lot of data to load if on dialup:

http://130.89.239.148/kforum/read.php?f=1&i=6473&t=6 473

a 1" ID x 5.5" (sans stub) diy pvc tube with ~0.1" initial gap and half ellipse form vs a modified X15 pipe (just "on-axis" meaning 30 degrees nominal tilt and also a perpendicular plot)

http://home.earthlink.net/~buddhaboy2/9v7.jpg  

Best,
Freddy

ps - thanks to Tom Danley for pointing out this thread

Karlson's list of inventions 1950 - note "controlled reverb" aspect of the coupler. -believe it occurs in tubes also.

LIST OF INVENTIONS 4/24/50

J.E. (Edward) Karlson

1. ELECTRONIC POTENTIOMETER. A variable element which is capable of linear variations of resistances with infinitesimal mechanical motion yet also have capabilities of broad variations in resistance.
2. CAPLESS DISPENSING TUBE. This device permits the use of toothpaste tubes, etc. without the necessity and bother of removing and replacing the cap after each usage.
3. GEOLOGICAL PROSPECTING SYSTEM. A system for use in the prospecting for oil, minerals, etc. This system may also be used for radar applications.
4. RADAR ANTENNA WITH AUTOMATICALLY VARIABLE BEAM PATTERN. This invention provides a simple means of automatically changing the beam pattern of a radar antenna from a pencil beam to a cosecant beam.
5. DIELECTRIC ANTENNA. This invention provides a technique for designing commercial and military antennas which will have overall dimensions than conventional antennae, and yet have equivalent gain and directivity characteristics.
6. BRUSHLESS DC MOTOR
7. ASHTRAY. An extremely simple design for an ash tray which quickly extinguishes cigarettes.
8. PRECISION DELAY CIRCUIT. This circuit provides a delayed pulse at a precise interval following an initial pulse.
9. CHATTERLESS CONTACTS FOR RELAYS
10. TELEVISION ANTENNA. This invention provides a simple, low cost antenna which can be readily hidden or obscured in the average room and is suitable for both F.M. and television.
11. SLOT ANTENNA. This design provides a slot antenna with broad band matching possibilities.
12. HYBRID WAVEGUIDE JUNCTION. This is a wave guide section which has variable propagation characteristics dependant upon the direction of propagation.
13. R.F. TUNER. a simplified tuner for F.M. and television use.
14. ADVERTISING SIGN. Novel electric sigh with quick change possibilities.
15. LIGHT VALVE FOR TELEVISION PROJECTION AND PICKUP TUBE.
16. ACOUSTIC TRANSDUCER. A novel loudspeaker enclosure with improved matching characteristics and controlled reverberation.
17. FISHING DEVICE
18. TELEPHONE AMPLIFIER WITH SPECIAL ACOUSTIC CHARACTERISTICS

Karlson patents

KARLSON PATENTS:

J.E. Karlson US 2586827 “Directive Radiating System” Filed March 31 1945

J.E. Karlson “Acoustic Transducers” US 2816619 filed Dec. 1951, granted 6 years later - probably due to RCA/Olson filing one - Karlson won.

J.E Karlson “Acoustic System” US 2896736 filed Aug. 1955 (reflective system to go with new "Karlsonette")

J.E. Karlson “Open End Waveguide Antenna” US 3445852 filed 1968 - essentially analogous with the K-tube waveguide used in Karlson’s X15 2-way speaker ~1966.

J.E. Karlson “Acoustic Transducers” - US 3540544 filed 1968 - concurrent with X15 and described Karlson’s use of ellipse based reflectors.

J.E. Karlson “Jet Engine Silencer Nozzle...) US 3543876 filed 1968 - jet engine muffler and rocket nozzles.  

Title: Karlson
Post by: Phil Pope on November 24, 2005, 09:06:56 am
Freddy

thanks for the interesting post.  Like the look of those clams in particular.  Can clearly see the 1/4 wavelength peak associated with the full chamber length.  Am I right in thinking that Reams' Karlson-Hypex is essentially a clam  chamber loading a variable expansion horn?

Phil
Title: Re: Karlson
Post by: Freddy Ireson on November 24, 2005, 10:56:49 am
Hi Phil - re: klam 18 made from one 4x8' sheet - not sure about 1/4 wave or BP peaking (?) - front is about 24" deep from nose to baffle - also there's a matter of microphone perspective vs its aperture affecting plots.

http://home.earthlink.net/~buddhaboy2/SK.jpg

subjectively in a modest size room, theres large changes in sound with small changes in aperture flare and/or gap. -- don't get much building done and lack math ability to digest some forumla but there's some K-guys who run 4-5 sets of CNC-ed wings and many variables per coupler.

Here's some impedance data on that klam before adding 0.6lb/cu.ft. polyfill to its ~85l chamber which lowered qtc to around 0.84 or so.

http://home.earthlink.net/~buddhaboy2/KFC

plugging the 2nd Z peak into winisd as BP4 front chamber tuning superfically looks similar.

re:Reams Hypex - IIRC path is about 2ft max so "path" shorter than La Scala.  Reams plots in the AES paper looked pretty strong. IIRC, rear chamber for each D140 was around 3 cu.ft. (apologies for mixing metric - lol)

Freddy
Title: Re: Karlson
Post by: Iain_Macdonald on November 24, 2005, 03:44:50 pm
Freddy & Tom,

I was wondering whether the Khyboe could be modeled as a Voight Rubber Throat.

Iain.
Title: Re: Karlson
Post by: Freddy Ireson on November 24, 2005, 04:40:10 pm
hi Iain  - one might look at Poppe's paper. discussion with a k-builder suggested making an impedance measuring tube (with 2 mic method rather than traveling wave type) to mount in place of a Karlson's driver.

K-Coupler paper

http://home.planet.nl/~ulfman/files/poppe_kcoupler.pdf

btw "the original" Karlson was the fifteen inch model introduced at Hotel New Yorker Audio Fair in fall of 1952 and its introduction went along with an Audio Engineering Magazine article. (which can be found at Job Ulfman's Karlson site)

Here's the fifteen inch Karlson plan as appeared in January 1954 issue of Radio & Televsion News

http://home.earthlink.net/~buddhaboy2/K15.PNG

the first Karlson 12 appeared in 1955 and sported reversible port panel for presence-control plus a movable wood bar mounted to the rear panel(three positions) adjacent to its rear lowpass shelf as
a damping control.  I have the factory 1955 blueprint and one exmaple. This Karlsonette could also be laid on its back to fire into a wall for "Aural Optics" and an optional spaced glass top available so it could be a bar! - this size coupler will kick some snappy midbass with lower Q woofer.

Karlsonette as bar http://home.earthlink.net/~buddhaboy2/BAR.jpg

btw "Leech" KHYBOE shown at Ulfman's pages appeared to be ~X15 size and not K15 size - although Walter Zintz mentioned a "shelf" (perhaps menat rear lowpass filer gap?)

at some point in time Acoustic Control introduced a couple of KHYBOE 115BK and BC2 - I have the 115BK

who was involved in this "collaboration"?  - did the late Dan Armstrong have intentions of reviving some K-stuff?

front view of Acoustic 115bk
http://home.earthlink.net/~buddhaboy2/ACAP.jpg

link to one of my posts on 115BK

  http://130.89.239.148/kforum/read.php?f=1&i=5739&t=5 739#reply_5739

btw - here's part of Ernst Beck's loudspeaker pages - looks like he was using Transylvania Tube in early 1980's:

http://www.biokurs.de/speaker.htm



Freddy

Title: Re: Karlson
Post by: Iain_Macdonald on November 24, 2005, 06:32:21 pm
Freddy,

I think that the Khyboe and the Tube are different in their treatment. To start with, the K tube can be considered as a resonating pipe. Then you can expand the complexity of analysis, like Poppe.  

The Khyboe (Bass) is different. The front of the driver has a short loading section with rapid flare. The rear also loads in to the front flare. Maybe I'm wrong, but looking at the picture links, I don't see that you or others, use the rear radiation of the driver, either by rear horn section, rear pipe or reflex loading. Why? You are missing 50% plus of the design concept and significant output.

Iain.

Title: Re: Karlson
Post by: Freddy Ireson on November 24, 2005, 10:16:16 pm
Hi Iain - my Karlson are usually vented  - sometimes with side gapped vents in the reflector which can't be seen directly from frontal view.

have 7 K15 enclosures (two definitely factory - two more in blonde formica "perhaps" - but no logos/decal(?) and a few old rough K15 copies accumulated plus 2 original X15, one original Karlsonette k12 from 1955 and one Acoustic Control 115BK (KHYBOE - I beleive - waht do you say?)

here's the Acoustic Control 115 BK from the Collaboration Series
(who collaborated??)

http://home.earthlink.net/~buddhaboy2/115BK.jpg

here's about the way the 115BK looks internally (this drawing was from a diy copy) - mine has a 20 degree baffle tilt, dimnsions IIRC of 27"H x 15"D x 20.5" W

http://home.earthlink.net/~buddhaboy2/ws.jpg

Best Wishes,
Freddy
Title: Re: Karlson
Post by: Ivan Beaver on November 24, 2005, 11:15:23 pm
I believe I have a drawing that I made of the Maryland Sound 1/2 clams that I had.   I will see if I can dig it up.  These were the concert versions.
Title: Re: Karlson
Post by: Iain_Macdonald on November 25, 2005, 04:40:12 pm
Hi,

OK, glad I was wrong about the vent.

But I am still thinking that the analysis of the Tube is going to be different to that of the Khyboe(Clam).

Acoustic - Well well... I seem to remember them producing a motor driven sub. It never made it to the UK. When was/is this  115BK produced. The Leech product had a huge vent, the width of the cabinet.

Fred Walecki at Westwood Music LA used to build Karlson cabs for bass players. Fred told me that his cabs were a direct copy of the original. Nicely made and very solid.

Iain
Title: Re: Karlson
Post by: Tom Danley on November 25, 2005, 09:27:31 pm
Hi Iain, Freddyi, all

I would agree the tube and “box” version are different.
In Freddyi’s post of Karlson’s patents, I see he played with antenna’s too.
This makes me sure that was the direction he was thinking as I have seen a balanced antenna which made me think, huh, a Karlson.

There are some amazing parallels between radio waves and sound but also some major differences.
For example, with an antenna, one reaches the radiation impedance of space with a wire a quarter wavelength long perpendicular to a ground plane (a mirror image). One can couple into that space at about 4X the impedance with a balanced (0 and 180 degrees) antenna made of two quarter wave lengths (half wave length overall).
For sound, that same “flat part” of the radiation curve is a function of area not conductor separation. .

Where a horn I think is a variable resonator (above the low cutoff  frequency) and like an electrical tank circuit can transform impedance’s from one end to the other, I do not see that in the box version of the Karlson, at least at low frequencies.
My guess would be that it is an acoustic low pass filter, which may have gain at the higher end of its response.  
A danger in drawing a conclusion from “close up” measurements is that when one changes the size of the radiation aperture, one can see differences in the sound level near field that are not related to acoustic power and would not show up at say 10 meters.
My hunch would be that if one measured the “box” version at 10 Meters, one would not find the “slot” increases the LF acoustic power (over some other shape), none of the dimensions are like what is needed down low.  
On the other hand, like any acoustic low pass filter, it will lower the distortion of the drivers output where it is rolling off.
Also, unlike any simple port used to make a low pass filter , one does not see organ pipe resonance’s, rather internal box modes mostly (it looks like) up high.

The Tube on the other hand is acoustically large enough in some of it range to do something unique. Exactly what I’m not sure, I’ve never seen a sensitivity or polar information on them. If it were also a variable resonator, then it could also provide an impedance conversion like a normal horn.

I do know that there is nearly always “another way” to solve a given problem and in antenna theory, there are things that look reminiscent of a Karlson and the goal of them is to provide a constant impedance over a broad frequency range (Freddyi, that book turned up).
It does make one wonder.
I suppose the thing to do would be to figure out how to model something with few enough segments and small bandwidth to work.

Iain, in that earlier post about Ted N., our PA wasn’t that loud, we had about 800Watts of mostly Tube amplifiers.  We played with Ted after Journey to the center… but right before he got big the second time.  I was 20 at the time so to me he was a scary fellow, although his brother was similar looking but a normal guy to talk to.
I found a link to a photo of the speakers we had in the PA and Gary Gand had one of me working on one of those tube amps back then fwiw.

http://www.livesoundint.com/archives/2003/april/water.php

Acoustic did make a motor driven woofer briefly, a subtec 2.6 or something.
This was an attempt to make a Servodrive but by using a crank throw, added the cosine distortion such a mechanism imposes.
I was pleased with Servodrive motor system, man its hard to believe that was 20 some odd years ago now. It did allow T&S parameters which one couldn’t make with a VC driver though, a key to making the horn work.

An interesting comparison can be drawn between the most powerful Servodrive, the BT-7 with uses a servomotor driver and conventional horn and the originating subject of this thread, the TH-115, which uses a conventional driver but a new horn configuration called a Tapped horn.
Four TH-115’s and four BT-7’s have about the same sensitivity / efficiency, the BT-7 is rated at 400Wrms, the TH-115 @1000Wrms.  The 4 BT-7’s are flat to about 32Hz, the TH-115’s to about 35Hz.  The Th-115’s, because of the different horn are about half the weight, cubic volume and cost.
Like I said to an old Boss, “there is nearly always a way to go around, under, over or bore through a technical problem”.   I think that is what Mr. Karlson was thinking too.
Anyway, the Karlson is a curious acoustic device, a better understanding and refinement of the various dimensions and shape could I think lead to something new also.
Best Regards,

Tom Danley

Danley Sound Labs

Title: Re: Karlson
Post by: Freddy Ireson on November 25, 2005, 09:29:19 pm
re:Acoustic Control 115BK - had large vent ~3" high by 9" wide - IIRC Z-minimum with EV15L is ~56Hz so there's probably some pipe action besides added mass-load on vent from coupler.

a description of "Westwood" bass-guitar bin was very close so will assume 115BK is very close in size and innards if not "exact" to Zintz/Leech KHYBOE(?)

here's an ~half-space (my yard drops/slides off about 8ft from mic - lol)
for the 115BK with EV15L - it must not have any more than 2cu.ft. rear chamber

http://home.earthlink.net/~buddhaboy2/AKTILT.jpg

a PV FH1 in the same spot would look like

http://home.earthlink.net/~buddhaboy2/FH.jpg

Freddy
Title: Re: Karlson
Post by: Freddy Ireson on November 25, 2005, 09:51:46 pm
Hi Tom (whoa - great pix!), Iain, Phil , guys (hey Ivan - U find  half-clam sketch?)

re: distance and plots here's an 8cu.ft K-box about like K15 but missing shelf refinements and loaded with a 0.25qts / 103g mms Eminence 18 vs UCS1 at 44ft distance. had K tuned ~42Hz z-minimum with two 4"ID x 4.5" long vents on its 1st reflector panel.  each cabinet was in same spot against corner of house and mic not moved:

http://home.earthlink.net/~buddhaboy2/44F.jpg

34Hz low level sine K vs UCS1 - 15dB more H3 on the pipehorn:
http://home.earthlink.net/~buddhaboy2/34hz.jpg

30vrms 50hz for K-box - careful not to smoke that coil!
http://home.earthlink.net/~buddhaboy2/30vrms.jpg

Rough side-view sketch of that 8cu.ft. k-coupler - its vents are 4.5"
holes on the 1st reflector panel. one board and an upper piece would probably be as good for midbass work. It started as a 15" coupler but got bored and took jigsaw to it to see what it would do with 18"
http://home.earthlink.net/~buddhaboy2/8cu.jpg

Another arrangement within 7.4cu.ft. which might work could be like so
(woofer is same Eminence 18" used in 8cu.ft. coupler above)
http://img358.imageshack.us/img358/4287/ha18capwjpg1co.jpg

This mod with extra cavity and a handful of polyfill produced the following 2M plots (rear chamber volume ~80l)
http://img408.imageshack.us/img408/7889/2mwebjpg4rx.jpg

whether sine testing showing high H3 has significant meaning vs "tone" - dunno

wideband, the original 1951-52 Karlson is probably tighter on than my box above - (15 vs 18 plus lowpass choke)

I'd normally tune this k a bit higher for a riper upper bass and nice shockwave effect. also like it as took one sheet of cheap plywood and weighs about 70lb loaded vs nearly double for the Unity.

The UCS1 had lots more 3rd harmonic than this k-box below 50.  UCS1 also has a higher Z-in - think around 10 ohms minimum- -neither are any good in my house for 32Hz -haha

John Karlson musta had good relations with Robert Moses as K15 (probably with EV 15RTX) was used in several exhibits at the 1964-65 World's Fair including Ford (with Disney Animatronics) GE and other exhibits.  a reliable source says Karlson did a rocket mic-speaker install for Moses and in abtract way reflected the twin-towers project.

FWIW in the legend of Karlson its said that loading below cutoff is one feature:

snippet from Dave Young's post:

I have built and used various Karlson couplers for PA since 1983.
There have been 15" and 18" woofers in 2'x2'x3' Karlsons of my own design.

"-For a while, I used X-15's for midrange with very
drastic equalization. I have used the Tube on top of a 12" Altec
for small jobs. I have also made a 2" Tube coupled to a Renkus-
Heinz 3300-8 for outdoor use. There are also some 12" coaxials in
use with a K-coupler for the highs.

As a low frequency cabinet, the Karlson is usable to 35hz with
low harmonic distortion.

Like any enclosure that depends on porting to augment the bass output, Theile-Small parameters have to be taken into consideration. I have yet to measure anything of comparitive size
that came close.

They get ugly above 175 hz. and require a crossover set from 100-150 hz.

The key to its low freq. performance is the coupled front chamber.

The increased air pressure loads the cone and dampens it.

A front loaded woofer and a horn loaded woofer operating below cutoff doesn't have that
advantage.

Twice I've measured the 3rd harmonic of 40hz(120 hz) louder than the fundamental with 100 watts
feeding the speaker.

The Peavey FH-1 and a Yorkville 2-18 with RCF's. When the 1504-4
Black Widow was tested in a 12 cu. ft. Karlson, the 3rd harmonic
distortion went from 103% to 8%. I didn't have the Yorkville long
enough to switch speakers."

***********

Carl says mass loading changes T-S parameters and evaluates up to 5 sets of wings (whew) - by his critera a Karlson bass coupler would not have a large rear chamber.

if feel up to it -  do some plots of Transylvania Tube in 15 degree increments at several heights.

re:K-Tubes - x15's tube imo has a significant ammount of energy propogated perpendicular to its long axis so theres a fairly high and even vertical window.  

Too Tall mentioned the Transylvania tube (which normally has slot "down" and tube angled up ~30 degrees) not having high vertical dipsersion - not sure - up close didn't seem to have much anything happening right above its structure- maybe it can be aimed towards the rear of an audience to good effect - straight down the tube would be imo where the highest HF goes (from listening to tape-hiss components)

Here's an indoors plot of a x15 copy with mic going up to overhead and perpendicular to the waveguide (loaded IIRC w. old PV 22A) the 1.875"ID tube on this Karlson x15 is mounted on its first reflector panel and aimed down 12 degrees from being parallel with the floor. (12 degrees subtracted from a nominal 35 degrees give the 23 degree baffle tilt)

http://home.earthlink.net/~buddhaboy2/X15/Perp.jpg

Here's same coupler/tube 85 to almost 90 degrees off horizontal axis in-room - that's the mic's position - lol

http://home.earthlink.net/~buddhaboy2/X15/Horz.jpg

like to get rid of that 2K2 notch - maybe wasn't as deep with 806a(?) was it from a diameter transition of a 1" OD 30 degree slice pre-waveguide to 1.875" ID tube?  

Karlson presented two circuit models for the coupler in 1952 Audio Engineering article - separate circuit for LF.

what type of Z tranformer (if any) is an Ultra-Fidelity type Karlson? - some couplers seem to have high outputs with good cone control.  there could be BP action - but is there more?

maybe they're 100% bunk - but can/or seem do some "stuff"/ give illusion - I like the vortex gun type effect on kickdrums

Best wishes to all
Freddy

ps - one more thing - here's plans for 18" 5181 10.3 cubic feet Karlson cabinet by Cetec-Gauss. note - dimensions on page one include carpet. look at page 3 before building - lol (also double check that wing radius to see if correct)

http://home.earthlink.net/~buddhaboy2/GK

can some K-couplers be made to work stronger within their passband for a given bulk by allocating more air-mass load from front chamber so rear chamber isn't quite as large as 5181's approach? - thoughts?
Title: Re: Karlson
Post by: Iain_Macdonald on November 27, 2005, 10:46:01 am
Tom,

Yes I have heard the Servo product. For a short time,(and not short enough for me) I was part of the company that imported Servo product to the UK, 1988 approx. We had 12 x SDL 5. They were sold to a "rave company", and the last I heard they were still working.

Now I know why you moved south.

http://www.tnugent.com/

Iain
Title: Re: Karlson
Post by: Freddy Ireson on November 27, 2005, 03:56:31 pm
Hey Iain, Tom and guys - IIRC there were other Karlson-types in the 1970's -  around 1971 I saw and heard "something on a pole" outdoors in a small venue which wasn't standard Ultra-Fidelity type nor klam-projector 'ala JEK AP and JEK's Oliver-Projects - wonder what  those were and what called? - didn't look DIY but could have been.

Freddy
Title: Re: Karlson
Post by: Phil Pope on January 04, 2006, 06:06:13 pm
Anyone got to grips with the Poppe paper?

http://home.planet.nl/~ulfman/files/poppe_kcoupler.pdf

I managed to struggle through the Marshal Leach horn paper but the Poppe paper is a bit beyond me.  

Got some spare Ciare 12.00SW drivers sitting around so I am going to try a 1.8m Klam and see how it goes. Hoping to get down to around 50Hz.

Anyone know how LF cutoff is related to length and cross-section area at both ends? What sort of T/S parameters are suitable for a Klam design? Is rear chamber volume important?

Phil

Title: Re: DANLEY Sound Labs TH-115?
Post by: Freddy Ireson on January 04, 2006, 09:35:55 pm
Hey Phil - you'll have to contact and engage Carl into some practical directions as to what will happen as he's built a number of AP-style klams.  I'd think be some coupled-cabity type action to  account for part of its response.  Ciare should be nice driver.

Best!
Freddy
Title: Re: DANLEY Sound Labs TH-115?
Post by: Phil Pope on January 06, 2006, 09:52:24 am
Freddy

you mention Carl in one of your other posts but where would I find him?

cheers
Phil
Title: Re: DANLEY Sound Labs TH-115?
Post by: Freddy Ireson on January 06, 2006, 09:39:04 pm
Hi Phil - here's Carl's note from K-forum


Re: trying to build new K's - can it be done? klam question
Author: Carl
Date:   01-07-06 03:24

Sealed Clam: System Q target for .7 , size back volume accordingly. High Qts drivers can compromise the design. Remember, if an optimum sized sealed box , systen Q = .7, is made bigger, f3 raises. Remember, the
addition of the K-Coupler raises the Q, lowers fs. You can test the speaker in air, and with the coupler in place to measure these effects. Then finalize the back volume for a system Q of .7 for the lowest f3. Add a Leach transform set to get the low cutoff you want. Without the transform, we were able to get a good dynamic response 60hz. We found coupler lengths as short as 26 inches and back volumes 1 to 1.75 cu ft to work well. The taper we liked best for the 12 was a Trax recommended by Ken. The length affects f3 more than the width. However, the projection pattern changes also with length so for home use shorter lengths might be more practical.


Title: Name
Post by: Craig Leerman on January 06, 2006, 11:36:30 pm
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