Hi Andy
There was a subwoofer shootout in Michigan last February put on by some of the guys over on the LAB.
There was a number of high end sub present (don't recall the list, but the link lists them). The comparison was in a large empty warehouse (similar to a shed event) and they had adequate power available for the subs Crown, QSC, (PL9.0 no less). The gear was setup using SMAART and the test was instrumented using Praxis.
The general consensus by all present (there were representatives from BassMax, Servo-Drive, etc.) was that the two horn loaded subs (BassMax and Lab) were on a totally different plane of performance compared to any of the direct radiators. In this shoot out they were mostly comparing against typical dual 18" (even a quad 18") subs. The horn subs were much cleaner sounding with less distortion and required less power to deliver more SPL. Pretty much a slam dunk over direct radiators.
http://www.live-audio.com/messages/archive5/35316.html
There is one potentially negative aspect about the horn subs. Some musical styles actually incorporate the harmonic distortion that direct radiator subs create and it is possible the horn subs clean sound will not satisify that style. Other than that there is no reason why I would want anything other than a horn loaded sub.
Phil
There was a subwoofer shootout in Michigan last February put on by some of the guys over on the LAB.
There was a number of high end sub present (don't recall the list, but the link lists them). The comparison was in a large empty warehouse (similar to a shed event) and they had adequate power available for the subs Crown, QSC, (PL9.0 no less). The gear was setup using SMAART and the test was instrumented using Praxis.
The general consensus by all present (there were representatives from BassMax, Servo-Drive, etc.) was that the two horn loaded subs (BassMax and Lab) were on a totally different plane of performance compared to any of the direct radiators. In this shoot out they were mostly comparing against typical dual 18" (even a quad 18") subs. The horn subs were much cleaner sounding with less distortion and required less power to deliver more SPL. Pretty much a slam dunk over direct radiators.
http://www.live-audio.com/messages/archive5/35316.html
There is one potentially negative aspect about the horn subs. Some musical styles actually incorporate the harmonic distortion that direct radiator subs create and it is possible the horn subs clean sound will not satisify that style. Other than that there is no reason why I would want anything other than a horn loaded sub.
Phil
very interesting i always wondered that if music was engineered to estimations of what systems ppl use
(i listen to hardhouse and hardtrance 
)
I keep thinking when I have a few weeks off that I will build a Lab horn, especially as the drivers are now easily available in the UK from BKelectronics. A few weeks because even though I am a good woodwoorker, the box is fairly complicated, and would take some fine tuning to get right.
Even though they are designed to couple in multiples for best response, I think that having one as a sub, doubling as a stand for my big TV would be quite cool
.
To avoid any magnetic interference problems I will just buy the driver first, and if I work out the distance the driver will be away from the tv if I put the box upside down, (with the driver access plate at the bottom), I can test the setup. If it fails, I'm sure I can knock up another enclosure instead, so the money won't be wasted.
Even though they are designed to couple in multiples for best response, I think that having one as a sub, doubling as a stand for my big TV would be quite cool
.To avoid any magnetic interference problems I will just buy the driver first, and if I work out the distance the driver will be away from the tv if I put the box upside down, (with the driver access plate at the bottom), I can test the setup. If it fails, I'm sure I can knock up another enclosure instead, so the money won't be wasted.
pinkmouse said:
Yep, built a large TL that was 4 seperate lines, one for each driver, and about the same physical volume as two LABs. Whilst I never compared them side by side, I'd say my KHorn is as good as it to 40Hz, with lower distortion (ear test) and better dynamics and I think the LABs will be an order of magnitude better.
Based on the test data I've seen for the LABs, loaded in quarterspace, and with 10dB or so of EQ I reckon I'll get mid 20's out of them, still with an effective efficiency of 100dB.
Cheers
So does LAB stand for Live Audio B... ? Just Curious.
Also, what makes the LAB horn so much better and economical that most anything else? Certainly better (in every aspect I can conceive) than anything else that has two 12" drivers moving back and forth. 100dB efficiency? Headroom at low bass? How do they do it?
Also, what makes the LAB horn so much better and economical that most anything else? Certainly better (in every aspect I can conceive) than anything else that has two 12" drivers moving back and forth. 100dB efficiency? Headroom at low bass? How do they do it?
Word has it these are a step down from the Servodrive Basstech 7's (The Basstech's going lower) Efficency wise, There are no dual twelves in the market that can keep up to the Lab Sub.
I'm not at liberty to go into details, for my knowledge is not up to par. Search the Live Audio archives ( 2000 - 2002 section) Your answers lie there.
I'm not at liberty to go into details, for my knowledge is not up to par. Search the Live Audio archives ( 2000 - 2002 section) Your answers lie there.
bostarob said:
Well. It started on the Live Audio Board, by users who wanted something better than the standard Dual 18 Sub. Many members shared their thoughts, and, ideas on what was needed. It was designed, to produce, the least amount of distortion (At Extremely High SPLs) at low frequencies (40Hz - down), with a high, efficency rating.
Which is the main factors for sound reinforcement.
So amateurs (not necessarily, a lot of them are engineers) worked together and designed this wicked sub? Wow, I'm impressed. I wrote Tom Delaney an email asking him if he knew of any good reads or links. I hope he's the right guy to ask - I remembered people talking about him as the inventor.
bostarob said:
I can see your Very Unfamiliar with the LAB Sub. Tom Danley is the main factor behind the Lab Sub.
Did you search the Live Audio archives post 2000 - 2002 era?
I hate to sound like a broken record, but, unless you do a search, you will never have the answers.
Oh, and for the record, I wouldn't call them (Lab Rats) amateurs.
They are experts in their fields, in Sound Reinforcement. But, I guess they would call Audiophiles amateurs as well. Its just a matter of having the right skills for the right applications.
For example:
Audiophiles use inefficent speakers, tune them very low, (20Hz - down)and use room acoustics to boost the gain.
This is due to a fixed installation (Living Room, Den, Basement, what have you)
Sound Reinforcement Guys, use high efficent speakers, tune them around 35Hz or so, and, use multiple drivers/enclosures to achieve a lower frequency without
any help from room acoustics.This is due to having to play
in all kinds of venue's and cannot rely on room acoustics to achieve a better sound.
Best Regards,
Sure, Mr. Danley is no amateur. One of the other guys there is a prof at Georgia Tech, so one could assume that the guys in there know there stuff.
Yes, I am Very Unfamiliar, and I've been sifting through the LAB forums, even from early in the life of the sub discussion, for a couple days now, looking for the basics, and all I've found is horn mouth size comparisons and other very focused things which don't mean all that much to someone who has not been following. I'm sure if I read the whole thing, I will learn something, but the amount of threads and posts are dizzying. I'll keep looking, of course, because it's interesting. In the meantime, however, could anyone who knows that forum know any good keywords to search for?
What about horn theory and design? Not just folded horns, mid and high horns as well ( I am assuming that they operate on the same principals, but I really don't know).
Maybe I should post a thread on that site? Or would I get eaten alive? I saw some threads that people had posted on the lab that got scolded for being out of context and asking dumb questions, that we would certainly put up with (chuckling)
We'll see...
-andy
Yes, I am Very Unfamiliar, and I've been sifting through the LAB forums, even from early in the life of the sub discussion, for a couple days now, looking for the basics, and all I've found is horn mouth size comparisons and other very focused things which don't mean all that much to someone who has not been following. I'm sure if I read the whole thing, I will learn something, but the amount of threads and posts are dizzying. I'll keep looking, of course, because it's interesting. In the meantime, however, could anyone who knows that forum know any good keywords to search for?
What about horn theory and design? Not just folded horns, mid and high horns as well ( I am assuming that they operate on the same principals, but I really don't know).
Maybe I should post a thread on that site? Or would I get eaten alive? I saw some threads that people had posted on the lab that got scolded for being out of context and asking dumb questions, that we would certainly put up with (chuckling)
We'll see...
-andy
bostarob said:
I've spent hours reading the archives. Its the best thing about site. Try "LAB Sub", "Lab Sub Tom Danley", "Lab Horn Project" for starters. You can also look for "Servodrive Tom Danley" for
the horns concept is the same. (With the exception of the Servo
motor of course!)
Search the Archives, 1999
To be honest, I post on the board with no problems. But, I am into Live Audio, so I have no backlash from my post. Gotta keep in mind, Live Audio is the only board (To my knowledge) that caters for Sound Reinforcement on a large scale level. You can speak to the average Soundguy, Regional Soundguy, the manufacter of a company, and so forth. This is why they (We) won't tolerate any off topic questions, and/or, to us, common sense questions.
There are a few of home audio forums about, which I post
also. (Audio Aslyum, Audio Karma, etc) Since you would like
to know the basics, on how horns work, your best bet is to
checkout the High Efficency Board, and/or PI Audio Board,
on Audio Aslyum.
They (We) will tolerate more 101 questions, than live audio.
Best Regards,
Hey, that's good stuff!
They recomend a paper: "One of the most important papers on horns is by W. Marshall Leach, Jr., On the Specification of Moving-Coil Drivers for Low-Frequency Horn-Loaded Loudspeakers. Available at the AES website as Preprint number 1405. This paper contains a model of horn loading based on electrical circuit parameters. Thomas Danley, a horn and sound pressure expert from Servodrive says this model is the most accurate for horn design that he has come across."
I think I should be able to get that for free, so I'll try that. That site seems to have more good stuff, so I'll keep looking.
Thanks,
andy
They recomend a paper: "One of the most important papers on horns is by W. Marshall Leach, Jr., On the Specification of Moving-Coil Drivers for Low-Frequency Horn-Loaded Loudspeakers. Available at the AES website as Preprint number 1405. This paper contains a model of horn loading based on electrical circuit parameters. Thomas Danley, a horn and sound pressure expert from Servodrive says this model is the most accurate for horn design that he has come across."
I think I should be able to get that for free, so I'll try that. That site seems to have more good stuff, so I'll keep looking.
Thanks,
andy
Also look at
#938 - Optimum horn mouth size by DB Keele and a couple of others he put out later (maybe around #1500?) about using TS parameters in bass horn design.
Anything by Keele, Leach, Dinsdale, Small et al on horns is worth reading. Others too, but I don't have them in front of me. Will add them later.
If you can get them for free, great, but most are only $5, and well worth it.
#938 - Optimum horn mouth size by DB Keele and a couple of others he put out later (maybe around #1500?) about using TS parameters in bass horn design.
Anything by Keele, Leach, Dinsdale, Small et al on horns is worth reading. Others too, but I don't have them in front of me. Will add them later.
If you can get them for free, great, but most are only $5, and well worth it.
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