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Author Topic: Reloading horn-loaded subs...what to get?  (Read 43233 times)

Callan Carnahan

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Re: Reloading horn-loaded subs...what to get?
« Reply #20 on: October 31, 2009, 01:45:37 PM »

Glenn, thanks a ton! I think that we'll undoubtedly go with these. Geez, I'm indecisive. I think you've finally helped me settle on some!
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Callan Carnahan

Elliot Thompson

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Re: Reloading horn-loaded subs...what to get?
« Reply #21 on: November 01, 2009, 08:02:16 AM »

How is the Selenium 18W FH801suitable for horn loading? Rolling Eyes

It offers a 5.25 mm xmax. I cannot think of anyone would look at an 18-inch driver for pro audio use with such a low xmax. The JBL 2441 offers more xmax than this driver and it is nearly 30 years old. How can you get 1600 watts continuous from an 18-inch driver with a linear xmax of 5.25 mm in a reflex cabinet much less a horn that offers a higher average cone excursion?

The Silenium’s Magnet structure is 120 ounces. The B-52 replacement is 220 ounces. I don’t need to even address the QTS. Anyone who is familiar with loudspeakers knows which one will perform better in a horn based on the weight of the magnet and, how it co-relates with the QTS. Not even the Reflex replacement on B-52’s website offers such a lightweight magnet as the Selenium. As a matter of fact, none of the replacement 18-inch drivers offered by B-52 is less than 200 ounces.

This is precisely why those who are not familiar with the technical side of raw drivers should not assume buying another brand other than the replacement OEM would automatically be an upgrade.

I wish you good luck Callan in choosing the replacement speaker for your cabinet. You seem easily influenced which is a salesmen's biggest sucker. Do keep that in mind.

Best Regards,
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Elliot

Glenn Williams

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Re: Reloading horn-loaded subs...what to get?
« Reply #22 on: November 01, 2009, 12:26:38 PM »

How is it suitable?

It was designed for the application. It is an E-horn retrofit.

A review on the website at Parts Express concurs with the more than 30 applications that I have used this woofer in. That review from 2007 was posted several years after I had been using them.

The B-52 information is eronoeous like most of the other information that they publish. It is all extremely suspect. Succinctly worded it is BS.

Their marketing misquotes driver specification among other things. How convenient for them.

In the Matrix 2000 when the sub woofer was blown by an aquaintence and removed it turned out to be 600 rms version rather than the 1000 watt version of the Celestion Woofer that B-52 marketing said that it was. hmmmmmm.....

They also embellish product by quoting one of their active/passive slave sub products as a system and not an individual box and were slippery enough to say that it was the sensitivity of "the system". System means both boxes instead of a single box. Since most ppl assume that this specification is quoted on a per cabinet basis it is very misleading. The actual SPL sensitivity figure will be as much as 6 db lower if they are quoting the additional amplification.

A 220 oz magnet structure ceramic slice in that diameter of magnet structure would require two ceramic slices sandwiched. The entire magnet "structure" including the metal casting might weigh 220 oz, but the actual magnet will be more like 109-120  oz. Both those magnet weights are common in the industry. Stucture is another slippery marketing term used along with magnetin the automotive car woofer industry to mislead ppl into believing that it is bigger than it is, so I am quite familar with it.

Furthermore,you make the assumption that the classic so called "E-Horn" is infact a horn.

I will grant you that in a true folded horn, the compression chamber and throat specifcations were optimized for one woofer, and another woofer will not function approprately. It is not wise to implement another woofer in an application designed as a system if one wants the system to perform optimumly.

However, E-horns are not folded horns at all. They may have a compression chamber, but the throat is a flared transmission line like passage, calculated at a given length in order to cordinate in a large port if you will which is also often mistaken for the horn mouth of a Folded Horn.

They are very forgiving in variances of most TS parameters and are not optimized like folded horns. They still require High Bl factors. If you had ever been inside the Earthquake or the Jr Earthquake you would have seen that the configuration is NOT a Folded Horn at all. Far from it.

An E-horn is essentially a derivation of a Voight Pipe.

Bill Wood's Yorkville LS1208 and LS808 used a futher derivation and tuned the flared port to to the front loading. Bill called this design a Dual Tuned Resonator. Yorkville marketing called it a Bass Pipe. A bass pipe is the generic term for Paul Voight's bass pipe, which in it's purest form is more of a transmission line that opens into a large a port.

Yes the Selenium mentioned is eminantly suitable for use in bass pipes, just as certain woofers work well in bass reflex boxes at a given tuning and certain woofers do not. Selenium knew that the E-horn was not a Folded Horn and the design reflects that. The majority of ppl in audio are not even aware of what a Voight Pipe is.

BTW: The technology is just as old as Folded Horns





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Elliot Thompson

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Re: Reloading horn-loaded subs...what to get?
« Reply #23 on: November 01, 2009, 02:53:03 PM »

Glenn Williams wrote on Sun, 01 November 2009 17:26

How is it suitable?

It was designed for the application. It is an E-horn retrofit.


Did you look at the cabinet in question? It is a Cerwin Vega copy. Cerwin Vega does not make any drivers aimed for horns using a QTS of 0.37  

Quote:


A review on the website at Parts Express concurs with the more than 30 applications that I have used this woofer in. That review from 2007 was posted several years after I had been using them.


Parts Express is aimed towards Home Audio & Car Audio enthusiasts. It is not a place where I would class the best source to research on bass horns in Pro Audio.

Speakersplans.com  is aimed for DIY horn designers in Pro Audio. PSW Subwoofer Forum is aimed to wards the Lab Sub. I’ll even say the High Efficiency forum on Audio Asylum is a good resource.

Quote:


The B-52 information is eronoeous like most of the other information that they publish. I is all extremely suspect. Succinctly worded it is BS.

Their marketing misquotes driver specification among other things. How convenient for them.


Pretty much like Selenium stating 1600 watts and having a voice coil winding depth of 22 mm, and an xmax of 5.25 mm. The Selenium driver you recommended has the specs of a driver designed in the 1980’s. It will not handle 1600 watts much less 1000 watts.
Did you happen to look at the AES rating? It says 600 watts.

Quote:


In the Matrix 2000 when the sub woofer was blown by an aquaintence and removed it turned out to be 600 rms version rather than the 1000 watt version of the Celestion Woofer that B-52 marketing said that it was. hmmmmmm.....



Was it the driver pictured on their website?  How did you confirm the driver was 600 watts? Why would B-52 put a Celestion woofer in their cabinets when, B-52 have been using Eminence for the past 10 years?  How do you know it was the original driver?


Quote:


They also embellish product by quoting one of their active/passive slave sub products as a system and not an individual box and were slippery enough to say that it was the sensitivity of "the system". System means both boxes instead of a single box. Since most ppl assume that this specification is quoted on a per cabinet basis it is very misleading.

The actual SPL sensitivity figure will be as much as 6 db lower if they are quoting the additional amplification.


Do you have any graphs to back up this claim?  We are talking about folded horns where it is standard to use blocks of four minimum.

Quote:


A 220 oz magnet structure ceramic slice in that diameter of magnet structure would require two ceramic slices sandwiched. The entire magnet "structure" including the metal casting might weigh 220 oz, but the actual magnet will be more like 109-120  oz. Both those magnet weights are commomn in the industry. Stucture is another slippery marketing term used along with magnetin the automotive car woofer industry to mislead ppl into believing that it si bigger than it is, so I am quite familar with it.


The Selenium FH 18W FH1P magnet from the manufacture states 120 ounces. The Eminence OEM magnet states 220 ounces from B –52’s website. That is documented for all to see. Where is your documented proof that the Eminence OEM magnet weight is indeed 109 – 120 ounces as you stated?

Everything I stated in regards to the Selenium FH 18W FH1P is documented in their PDF specifications. Where are the documents in regards to what you stated above so, I can read for myself?

Quote:


Furthermore,you make the assumption that the classic so called "E-Horn" is infact a horn.

I will grant you that in a true folded horn, the compression chamber and throat specifcations were optimized for one woofer, and another woofer will not function approprately. It is not wise to implement another woofer in an application designed as a system if one wants the system to perform optimumly.

However, E-horns are not folded horns at all. They may have a compression chamber, but the throat is a flared transmission line like passage, calculated at a given length in order to cordinate in a large port if you will which is also often mistaken for the horn mouth of a Folded Horn.


Surely you are joking right?

Are saying that one B-52 is going to offer the same low frequency extension as block of 4 – 8 cabinets?


The B-52 copy is a Cerwin Vega design that stretches back to the 1970’s. Please tell me which model number Cerwin Vega offered that matches the TS Parameters in the QTS as the Selenium 18W FH 1P?

Quote:


They are very forgiving in variances of most TS parameters and are not optimized like folded horns. They still require High Bl factors. If you had ever been inside the Earthquake or the Jr Earthquake you would have seen that the configuration is NOT a Folded Horn at all. Far from it.

An E-horn is essentially a derivation of a Voight Pipe.



No folded horn is very forgiving on the incorrect driver. I don’t think you are familiar bass horns as you assume.

Why don’t you post some frequency and excursion charts of the Selenium 18W FH-1P in the box in question?

As a matter of fact, since you are so familiar with the raw drivers of the Eminence OEM used in the B-52 Folded Horn, why not post some charts of the stock driver as well so we can see why the Eminence OEM designed specifically for that box will offer an inferior response to the Selenium 18 W FH – 1P


Quote:



Bill Wood's Yorkville LS1208 and LS808 used a futher derivation and tuned the flared port to to the front loading. Bill called this design a Dual Tuned Resonator. Yorkville marketing called it a Bass Pipe. A bass pipe is the generic term for Paul Voight's bass pipe, which in it's purest form is more of a transmission line that opens into a large a port.



The B-52 (Cerwin Vega copy) is not the Yorkville LS 1208 & 808 that is designed to be used singular. The B-52 (Cerwin Vega copy) needs to be in blocks of 4 to take advantage of the coupling of the horn’s mouth (SPL) and, achieve low frequency extension.

Quote:


Yes the Selenium mentioned is eminantly suitable for use in bass pipes, just as certain woofers work well in bass reflex boxes at a given tuning and certain woofers do not. Selenium knew that the E-horn was not a Folded Horn and the design reflects that. The majority of ppl in audio are not even aware of what a Voight Pipe is.

BTW: The technology is just as old as Folded Horns



I’m pretty sure anyone who is familiar with horns is familiar with the Voigt horn.
However, the B-52 (Cerwin Vega copy) is not a Voigt horn. I don’t know why you would compare the B-52 (Cerwin Vega copy) to Yorkville when the designs are not the same.


Cerwin Vega

http://www.cerwinvega.com/images/foldedhorn2.gif


Voigt Horn
http://www.troelsgravesen.dk/SP200_files/quarterwave_1.jpg


There are no characteristics amongst these two designs, hence comparing the two is like apple to oranges.




Don’t forget to post some frequency/excursion charts of the Selenium 18W FH 1P in the B-52 (Cerwin Vega copy) so we can see why it is a superior driver over the OEM Eminence driver designed to work on the B-52 (Cerwin Vega copy) cabinet.

Best Regards,
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Elliot

Art Welter

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Re: Reloading horn-loaded subs...what to get?
« Reply #24 on: November 01, 2009, 04:54:49 PM »

Elliot,

The B-52 18-220S 18" Magnet structure is listed at 200 oz,(or 220 oz) the speaker weighs 26 pounds.
The Eminence 4018LF magnet structure is listed at 109 oz, the speaker weighs 26 pounds.

Looking at various pictures of 18” speakers, all of which come in at similar  weights and magnet ratings, it is obvious that the B-52 magnet structure weight is off.
Since they don’t publish the TL specs, hard to say what the BL specs are, or speculate on it compared to any other speaker.

The Lab 12, with a BL of only 15, and QTS of .38 obviously is a lousy horn driver...

I take the empirical approach.
Build, listen and test.
Having loaded similar horns with speakers with widely varing BL ratings (not to mention size, QTS, etc.) I have got results that very suprisingly little in frequency response and efficiency.
Harmonic distortion is different with the different speakers, so they do have markedly different “sound”.

I have heard the B52 with the stock speaker, it sounds  better than the Cerwin Vega, louder (more sensitive), cleaner (less harmonic distortion), wider frequency response (both top and bottom), not “sludgy” (goes "thunk" with a 9 volt battery, not duuhthhh).

I would be willing to bet that all the speakers mentioned would work OK in that type of box, and that there would not be a clear winner, even including the Cerwin Vega, some people go for that sound.

That said, I’d stick with the stock speaker, so any expansion won’t require retrofit, and additional rental speakers would match up.

Art Welter
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Elliot Thompson

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Re: Reloading horn-loaded subs...what to get?
« Reply #25 on: November 01, 2009, 07:14:27 PM »

Hey Art.

The Difference between the Lab Sub and the B-52 is the longer horn-path. With a longer horn-path, you can indeed use a loudspeaker with a higher QTS rating.

However, with every driver that falls within the B-52's horn path 0.3 QTS is the limit. Optimum performance using cabinets that are or similar to the Cerwin Vega is always 0.3 or under which the majority of Cerwin Vega 18-inch drivers fall under.

Actually, the only cabinet that offered a higher QTS than 0.3   was the old EAW BH 800, which brings forth a longer horn-path than the Cerwin Vega L 36 and, W Bins.

But the real issue is the xmax. 5.25 mm is nothing considering 9 mm is the standard these days. When we take into consideration an 18-inch driver sitting in a sealed chamber, will offer even more excursion than a vented enclosure, I don't see how the Selenium is going to exceed the performance of the OEM Eminence.

I just scaled the Selenium 18 FH 1P in the B-52 box and, the most I am getting before exceeding the 5.25 mm linear xmax is 600 watts @ 66.6 Hertz which, co-insides with AES rating of 600 watts on the Selenium 18 FH 1P spec sheet. Surely, not the 1600 watts Selenium marketed.

http://img524.imageshack.us/img524/2738/65473835.png

I also scaled the Eighteen Sound 18 LW 1400 in the B-52 box and, I can now achieve 38.0 Hertz before exceeding the linear xmax of 9 mm @ 600 watts. So, it is obvious which driver would be a better replacement. It also offers the correct QTS, lower FS than the Selenium and, a higher xmax.

http://img265.imageshack.us/img265/8447/48054130.png


   http://www.eighteensound.com/index.aspx?mainMenu=view_produc t&pid=197

Personally, I would consider the Eighteen Sound 18 LW 1400 an affordable driver but, I am very critical to sound.

The issue is not finding a replacement. It is the user not willing invests in a better driver. I could name a few but they are not $200.00 Actually the Eighteen Sound would more than likely be the cheapest driver that I would recommend under the given conditions.

Possibly I am just a little to critical when it comes to sound. But that what makes Elliot, Elliot.  Cool

Best Regards,



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Elliot

drewgandy

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Re: Reloading horn-loaded subs...what to get?
« Reply #26 on: November 02, 2009, 10:00:11 PM »

Elliot Thompson wrote on Sun, 01 November 2009 18:14


But the real issue is the xmax. 5.25 mm is nothing considering 9 mm is the standard these days.


Have you looked at the klippel data for these?  How about determining how many db's the difference actually makes?

Quote:


Possibly I am just a little to critical when it comes to sound. But that what makes Elliot, Elliot.  Cool

Best Regards,




Methinks the difference is being overstated. But that's what makes Elliot, Elliot. Wink

Doubling the cost of a (already cheap) speaker for a couple decibels of "improvement" is not what I think this guy is after. That's not to say that the 18sound won't be better.  I just question how much better.
More than likely some modeling in hornresp of some of the Eminence models will reveal some economical and workable options.    And Art's suggestion of keeping it stock has merit.  I would be trying to determine if the oem unit has an over the counter equivalent.  That magnet doesn't look like a normal Eminence.

drew
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Callan Carnahan

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Re: Reloading horn-loaded subs...what to get?
« Reply #27 on: November 02, 2009, 11:30:26 PM »

drewgandy wrote on Mon, 02 November 2009 22:00


Doubling the cost of a (already cheap) speaker for a couple decibels of "improvement" is not what I think this guy is after.  


Precisely.

Just bought two replacements straight from B-52; one for this broken one, and one as an extra. I figured Art's right. Stick with the stock speakers. Then I know it works, fits, sounds fine, (hopefully) lasts, and if someone I sell them to (eventually...they're wayyy too physically big for my 6x12' box trailer) wants to know how they sound, then they'll have the "original" sound and I have no explaining that I have to do. I just get rid of them and get some 728's  Very Happy

Thanks for the help though, guys. You guys amaze me with how dedicated to your practices you all are. It's great to be able to learn from you all and get your input. Much appreciated.
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Callan Carnahan

Elliot Thompson

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Re: Reloading horn-loaded subs...what to get?
« Reply #28 on: November 03, 2009, 01:09:47 AM »

drewgandy wrote on Tue, 03 November 2009 03:00

Elliot Thompson wrote on Sun, 01 November 2009 18:14


But the real issue is the xmax. 5.25 mm is nothing considering 9 mm is the standard these days.


Have you looked at the klippel data for these?  How about determining how many db's the difference actually makes?

Quote:


Possibly I am just a little to critical when it comes to sound. But that what makes Elliot, Elliot.  Cool

Best Regards,




Methinks the difference is being overstated. But that's what makes Elliot, Elliot.

Doubling the cost of a (already cheap) speaker for a couple decibels of "improvement" is not what I think this guy is after. That's not to say that the 18sound won't be better.  I just question how much better.
More than likely some modeling in hornresp of some of the Eminence models will reveal some economical and workable options.    And Art's suggestion of keeping it stock has merit.  I would be trying to determine if the oem unit has an over the counter equivalent.  That magnet doesn't look like a normal Eminence.

drew


If you haven't notice, I was the one saying stick with the OEM driver from my first reply.

http://srforums.prosoundweb.com/index.php/m/0/50507/0/83/#ms g_485824

Callan is hard pressed to find a driver that would match the performance of the OEM replacement under the price point B-52 was offering.

The Horn can only dictate what it can control within its band pass. Below that, it is the sealed chamber will determine the longevity of the driver from a cone excursion point of view.

Whether you use Horn Response or Eminence designer, the excursion will be the same since both programs are simulating cone excursion from 60 Hertz downward in a sealed chamber.  

I used the Eighteen Sound as reference to show why the Selenium driver was a poor choice as a replacement. I made it clear from page one that a replacement driver suited for the B-52 (Cerwin Vega copy) would be outside the $200.00 range. I can't think of anyone would class 66 Hertz acceptable for bass when using Cerwin Vega copies and, showing a simulated graph on what to expect is far better than crossing your fingers and wishing for the best. If I had the TS Parameters of the Eminence OEM, I would have easily compared it to the Selenium.  

Bear in mind the smaller the xmax, the lower the output as the driver moves further down in the frequency band. So, the output is significant from 50 - 40 Hertz when comparing both drivers. You need to move air to attain a lot of output when it comes to sub bass.

Best Regards,



 


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Elliot

Callan Carnahan

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Re: Reloading horn-loaded subs...what to get?
« Reply #29 on: November 03, 2009, 09:01:59 AM »

Callan Carnahan wrote on Mon, 02 November 2009 23:30

drewgandy wrote on Mon, 02 November 2009 22:00


Doubling the cost of a (already cheap) speaker for a couple decibels of "improvement" is not what I think this guy is after.  

I figured Art and Elliot are right. Stick with the stock speakers.


Sorry to deny credit where credit is due, Elliot  Confused


I'm going to e-mail B-52 and see if their general questions guy John can tell me what the X-max and BL and QTS on their speakers are. Would it be okay if I PM'd you, Elliot, if he gets me those numbers and you could run them through your program to see what I can realistically run through wattage-wise it without wreaking havoc on it (again)?
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Callan Carnahan

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