Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Randy Freemire]

Hi- I was looking through the LAB SUBWOOFER with great interest but haven't seen the overview that I was looking for.  I looked through the stickies, and while it's showing alot of technical details, I didn't see the big picture anywhere.

Would someone make a sticky, something like "LAB SUBWOOFER PROJECT: Big Picture" and include the basics for someone like me that doesn't have a clue how to put all this info in context.

1. Approximately how long it would take for someone with moderate woodworking skills to make one of these boxes.  How about the second one?

2. Is there just one or are there several sizes (they seem huge from what i've seen).  What do they weigh?  What does it take to man handle them?

3. What's the approximate cost for wood, speakers, etc.

4. What do they compare to?

5. Is anyone making parts (such as cutting out all the pieces that you then assemble and glue)?

6. What amplifiers and DSP are used?


I imagine these basic questions are answered if you spent several hours on this site, but I don't know why you'all wouldn't just put an overview Sticky up that answers these very basic questions.

This must be one hellofa subwoofer if it's in the same league as a EAW sub going for a coupla hundred grand!

Thanks!

[Tim McCulloch]

Hi Randy-

I suggest you *search* for the stars....

Use Google and append this to your search terms to limit hits to the Live Sound forums-  site:srforums.prosoundweb.com

The info is in here, trust me.

I haven't built the LABsub, but I followed the project from the first comments by Tom Danley, so I can answer a couple of your questions.

There is only 1 size, and it uses only 1 specific model of speaker.  It's a custom job from Eminence and available from Parts Express or any Eminence dealer.  They are "truck-pack friendly", sized at 22.5" x 45" x 45" and weigh around 230-250#.  Some folks say theirs weigh more...

Depending on materials, methods and finish, the cost per unit has been reported between $600-$800 each but those are old numbers.  It might well be more now.

These compare favorably with Speakers You've Heard Of

[Oskar Rei]

I'll try to answer questions Tim McCulloch hasn't.

1) For me it took about 3 days to build the first, but it's possible to build approx. 1 in a day, when using right equipment and cutting pieces out for many subs once. The measuring and preparations for cutting takes most of the time, because every mm is cautious.
So for me 3 days to finish the box without cutting the metal access panels and paintwork.

3) From hard plywood, i got my box weighting 280lbs, considering access panels and drivers weight 10kg each. But it's possible to make it a lot lighter. I didn't also cut away the excess material from the back side.

2) Actually there are several LABhorn designs with slight modifications, but the best is still thought to be the first one, which blueprints are here in prosoundweb site. Also there are half labsubs, which use only one driver and maybe are more user friendly in smaller applications.

Cheers,
Oskar

[Randy Freemire]

Tim and Oscar,
Thanks for the replies!

Wow, that's quite the box!  As I've been doing research for getting monitors/foh for a band, a top concern has been size and weight.  At 230-280#, and with that form factor, that's an awkward beast! Obviously casters are part of the design, and a buddy is required.  
I'd be curious to know what the lightest version of this sub is (without compromising performance)?  
So a half sub is the same size box but with fewer drivers?

So,I guess the question here would be, in order to achieve the tight, loud, low low bass this box is capable of, what comparable products are out on the market?  
Does it require something massive like this to achieve such remarkable results?  

The ones I'm familiar with (from forums) are much smaller units like the JBL PRX 618xlf, various Yorkville subs (most around 100#s and less than $1,000), and those obviously don't go near the sub 30hz range.  I saw a post comparing it to a massive eaw box (KF940), and that sucker costs over 2 HUNDRED THOUSAND DOLLARS!!!  That boggles my mind.  
But Tim said it out performs subs costing 3x's as much, so say commercially available subs in the $2,500-$3,000 range, right?

And what kind of spl at different frequencies are achieved?  I'm a little confused on this as sometime people talk about full space and half space measurements, not sure what they mean.

As far as building it, it looks pretty tricky.  I checked out various build photos, and there's lots of curves and strange clamping angles.  I guess it's one of those things that looks intimidating, but once you've actually done one it's not so bad.
So Oscar, when you say every mm is cautious, do you mean that in order to get all these strange angles to line up, you've got to be super precise?  

So, if this is a passive box with speakers, nothing else, what kind of wattage does it take to get the full sound out of this sub?  
Are there specific amp models that have found favor for this sub?
And the DSP?
That must be on hellofa 12" speaker to perform like that- but 2 are used, right?
Is this design/speakers efficient compared to other subs in this league (which of course becomes an issue when blowing fuses and paying the electric bill for a show).
Tim, when you say $800, that's just for the finished box; with an amp and dsp I imagine the figure is closer to $1,500?

Thanks for the replies!!!  A sticky with these kinds of questions answered would be most appreciated for new folks like me!

Randy

[Jeff Bailie]

Hi Randy..

I hung out and read this forum from end to end for about a year before I decided to go for it.

I have 12 Labhorns now. They averaged about $1000 each to build.

When I started I had never used a table saw before. The first 6 took me almost 2 months to build, and I worked 8 hour days.  

I know there are a lot of choices out there. I know there are cabinets that go lower, and louder. You can find cabinets that use 4 times as much power. And you can defiantly find lighter cabinets to drag around. But in my experience, I have never listened to a better sounding Bass Cabinet.  It has very low harmonic distortion. And it's also a long horn length.

I suggest the same as Tim.  Start searching around. The more you read the more you will like the Labhorn...


 

[Oskar Rei]

Randy Freemire wrote on Thu, 16 December 2010 18:49

I'd be curious to know what the lightest version of this sub is (without compromising performance)?   So a half sub is the same size box but with fewer drivers? /.../ But Tim said it out performs subs costing 3x's as much, so say commercially available subs in the $2,500-$3,000 range, right?

Actually no, I'd say half Labhorn is totally different design, and obviously not that efficient as Danley original designed sub when using both in bigger stacks. If I remember correctly, there were topics about half Labhorns in this site, but I couldn't find them right now. But search and learn about different subs and find the best one that suites for you. LABhorn has quite good response, SPL and efficiency gets even better as using them in larger racks- consisting from 6-8 subs stacked together.

Quote:

And what kind of spl at different frequencies are achieved?  I'm a little confused on this as sometime people talk about full space and half space measurements, not sure what they mean.

The response around 30-40Hz builds up when using more than 2 subs, with 4 subs the response is quite flat from 30 to 80Hz. 4 LABhorn's stacked together could average about 138dB/1m.

As you know air travels more spherically away from speaker as the frequency lowers, think of omnidirectionality. As still horn speakers are more directional, speaker response gets better as it reflects from some kind of plane (etc floor, wall...). So full space should theoretically be place where air travels beyond meeting any obstacle and half space means speaker gets reflection from one plane, quarter space from two planes and so on. Reflection from one plane should add approx 3-6dB to response.

Quote:

So Oscar, when you say every mm is cautious, do you mean that in order to get all these strange angles to line up, you've got to be super precise?

As I looked into these different LABhorn designs some time ago, the compression chamber was modified vastly with newer modifications (for bigger compression ratio=louder) but actually the response didn't change so much as effecting the durability. What I thought before, is you should line up everything that it gets all air tight, especially the compression chamber. It is mentioned even at LAB12 driver specification sheets that any air leaks in Labhorn design could destroy the driver quite easily because of its very loose suspension. So it's not (only) about the measurements, but to get it all air tight and line up, but if you take your time building it, it isn't so complicated.

Quote:

So, if this is a passive box with speakers, nothing else, what kind of wattage does it take to get the full sound out of this sub? Are there specific amp models that have found favor for this sub? That must be on hellofa 12" speaker to perform like that- but 2 are used, right?

I'd use lower power and more cabinets, but i've read they could handle 1.6kW a cabinet with cooling plugs for long time term. So i 0.8-1kW should be fine, but someone should add their experiences and thoughts. One thing to consider when choosing amplifier is, it should have a little bigger tolerance on output impedance as the Lab cabinet’s is about 3.3 Ohm on lower points.
Yes, there are two drivers, but keep in mind, as one of the driver fails, the other will also in the matter of time. Because they both fire into thought to be high pressure cavity to limit the Xmech of the driver, the space of the chamber theoretically doubles as one driver fails.

I’ll add a link to LABhorn measurements done by Tamas Tako link.
And measurements done by me, but these creditability aren’t much because of homedone microphone calibration. link

Quote:

Is this design/speakers efficient compared to other subs in this league (which of course becomes an issue when blowing fuses and paying the electric bill for a show).

The response is quite fair and gets better when adding more of these cabinets. 12pi is undoubtedly better design for PA but I don't know about getting drawings from the author Wayne Parham. The 12pi uses same LAB12 drivers and has better results. You should find these subs comparisons by searching Prosound Shootout.

I’ll add that, I would definitely go with LABhorns or 12pi’s.

Cheers,
Oskar

[Brandon G Romanowski]

I agree a singular, entire project page with specs etc.  would make things clearer.

[Chris Jensen]

Randy,

I'm almost sure that 90% of your questions would be answered on the page 24 or 25 of the posts.  This project is about way more then a good sub.  There is so much information from some great minds that has been compiled over the years on here.  Simply adding a "sticky" page would allow you to miss so much about these things.  There is no simple answer to building these.  You need to understand the evolution.  The reason why is there is almost zero consistency from build to build.  When you buy a box it is made the same way with a quality control.  You may blow up your cabs and by not doing the reading you won't have any idea why.  There have been many over the years that ask the same questions over and over, my favorite is I keep blowing drivers with putting low power into them.  It almost always ends up the chambers aren't sealed.  There are questions about epoxy vs glue, paint vs line-x, handles and wheels, the list goes on.  The only way you will answer these questions are to read other peoples answers.  Think of the entire sub section as a massive sticky for all the talk on the Internet for the LAB.

I know that isn't what you want to hear, but it took me almost 6 months of reading before I got stared.  Almost every question I had was answered by someone else prior to me even making sawdust.  I have been lurking on this board for about 6 years and the thing that Labsters hate the most is answering the same questions.  I mean they hate it.  One of my favorite things is to look at topics and see something like "I need a speaker system, it will be for reproducing audio.  What should I get"  and I know the first post under it will be Ivan grilling the hell out of them because they have no idea what they want, and there is no answer for them.  People on here are more then happy to help provided you are will to seek out the info it it exists already. Unfortunately you missed the evolution of this project and no one is really interested in hashing it all out aging, so you need to catch up and you will be shocked by how much info there is that a sticky would never give you.  

Ok now that my rant is over.  You need to look at the impedance chart and understand it.  It goes to 27 hz and should be passed at 80 or so.  It will handle a ton of power if needed and run correctly, there are numerous threads about amp combos.  4 or more is almost necessary as one cab is 1/12 of the horn mouth it makes.  You can corner load a single can and it will help a lot.  The plywood will be expensive don't skimp out.  13ply 18mm birch.  The next question you have will be the plans are only in inches how do I use 18mm that is all I can find.  There are threads about how to convert and how to align the module for the best possible outcome.  And lastly I can't stress enough, this is some wicked woodwork!  Remember 1 degree over 12" is almost 1/4", these cuts are to a fraction of a degree.  I don't mean to sound like a jerk or scare you away but I don't feel a simple sticky will really give you the scope of your undertaking.  I mean it seems to good to be true right?  A sub that will kick the big boys asses and cost well under a $1k.  The worst thing is that you start this and invest time and money into this and get stuck or worse discouraged if you are in over your head on skill level or time.  My dad is an extremely experienced wood worker/cabinet builder, I got in over my head and was lucky enough to get some help, so if you have a resource line it up first.  There will be nothing worse then several hundred dollars of plywood cut either wrong of unused.  

Again sorry for the rant, but this isn't another site with plans to build the next best sub that some guy built in his garage then posts the plans in one shot.  This thing has history, understand Servo-drive and SPL to know where the Lab comes from, and who is behind it.  Check out Peter Sylvester's site, there is some good info there too.   http://web.archive.org/web/20050209025454/home.comcast.net/~ labhorn/

Good Luck and happy sawdust making!
Chris Jensen

[Randy Freemire]

Chris,
You make a compelling case and I agree with you- for the most part.  But I don't think this needs to be either/or.

For many of us this is part of a larger learning curve.  Whether you're taking the time to learn how subtractive synthesis works in your keyboard (and not being a preset player), learning the technical intricacies of doing live sound well, getting proficient with a DAW, or building your own tour quality sub for a decent price, etc. etc., it's all a matter of time, interest and application.  Usually lots and lots of time.  

As someone who has visited this site a number of times and not known what to make of it, I think a sticky would be well placed, and would serve better to lure more people who would potentially be interested but don't know what to make of it.  Sure, it proves you're among the dedicated and persistent if you take the time to put together all the pieces yourself, and I applaud those who do so, in any field.  But this is not a Disney ride where you pay your money and get a pre-determined thrill, it's backpacking, where you earn every bit of your enjoyment, and I don't see anything wrong with having a rangers station for orientation.

It wouldn't take much- give the general parameters of what is being aimed for here (like the questions I've already posed), and what the motivation is (how these subs compare to what you'd have to pay commercially for them, and how good they sound).  Then say something to the effect of what you said in your post, making clear that what has been explained is a little primer on why this sub project is an exciting possibility, and to get the real meat of the matter you need to read a lot more.

And then at the end of this overview (which wouldn't need to be much longer than the length of what you wrote) put in 10-20 links with good descriptives to various posts within this forum that are especially excellent for various reasons.  That, or use the space to the left of the topic listings to display a special icon that identifies those posts that the moderators or a polling of forum members think is crucial reading for beginners.  And having read some really good posts, the newcomer to this forum will be hooked even more.

So- is the goal to maintain purity, that those with enough desire will find their way through this forest of information?  Or is the goal to build a community of people excited about building their own diy sub?  Even if you enacted my suggestions, people are still going to have to read an enormous amount of postings and become somewhat obsessed with the project.  Personally, I believe that you'll attract a larger number of people who would get onboard by having a friendly ranger and more sign posts out.

For what its worth,
Randy

[Tim McCulloch]

I'll answer the last question... yes, to a certain degree it IS about "purity."  Perhaps it's the quaint, old-fashioned thrill of understanding the technical posts after reading a couple hundred of them.  Perhaps it's because knowledge is more than mere facts or statistics; wisdom is more than mere knowledge... and there is wisdom, some profound, that looses it's impact when not read in the context of perhaps dozens of posts.  As Chris points out, the journey *is* the destination.

This project was about the idea that a high-performance horn sub could be designed and built in a collaborative manner, with Danley doing the design & modeling and forum users making sawdust.  Tom speculated that this DIY project would embarrass more than 1 manufacturer, too.  Frankly it's not about driving page traffic or turning this particular forum into a generic DIY sub forum.  Those already exist.  It's about getting insight into horns & how they work, and the LABsub is the practical exam.

Someone with time could put together a page of links for the mods to sticky... but that someone has yet to appear.

Have fun, happy subbage.

Tim Mc