|
High Efficiency Speaker Asylum Need speakers that can rock with just one watt? You found da place. |
|
|
|
High Efficiency Speaker Asylum Need speakers that can rock with just one watt? You found da place. |
|
In Reply to: Re: Solution indicated by conditions posted by Wayne Parham on March 4, 2003 at 01:34:15:
Hello!
What is your relationship to this project, and to Tom Danley? I see that you are a manufacturer, and I sense that you tend to feel somewhat defensive of the LAB horn design. I also can't help but to notice that you've only posted twice on this website - TD - and both were in response to this thread. So what is the nature of your participation in this matter?*Hi Wayne
*Easy big fella', let’s just put the safety back on and put it back in the holster. I come in peace; I mean you no harm.
*Peace, love and road hockey is what it’s all about.
*My relationship is as follows. I am one of the mystery lab participants. I built, tested and listened to the very first Lab horn once Tom finished designing it. I did this out of interest seeing a possibility to learn something new. At the time (and still to this day) I have never met Tom in person, I just sent him the measured results with an introduction of who I was and why I built it. Why the mystery, well until lawyers are finished with certain “things†that have evolved between our two companies since then it must remain this way. This is not an attempt to duck and hide so please do not accuse me of this. I have only posted twice on this forum preferring to sit and watch especially the posts between your self and Tom regarding the Unity horns. It’s almost at times like a scene from a Monty Python film, great stuff and very informative. So I have NO involvement other than one of trying to learn and help out in the Lab project where I could.
Anyway, you wrote:
>> There is no need to review these requirements as I am sure you
>> have followed the Lab horn project from the start.
Actually, no I haven't. I became aware of it a few months ago when the drivers were already being promoted.
>> Tom was asked to design a subwoofer (which he did for free) with
>> a certain set of requirements that were dictated by the people that
>> were going to build and use it.What "certain set of requirements" might this be? And what was the reason for setting those particular requirements? It appears that they may have been set by a group that is primarily ServoDrive customers, and that this has been an effort to mate a bass subsystem with another existing product in their line. Or perhaps it is to replace an outdated woofer product offering. Those reasons would make perfect sense and are reasonable goals. But I have no reason to tie myself to this particular set of constraints.
* I do not think that the people that have built the Lab horns are necessarily Servodrive customers. If you have followed the project from the beginning it sounds (to me) like there are all kinds of people building these boxes for many different applications from home theater to small PA businesses.
>> This is how the size of cabinet, portability/truck pack requirements,
>> frequency range of operation and desired target output were set.
Am I correct that this is mostly people that are already familar with other Danley offerings? Were the design goals driven largely by the need to mate with something else in the line? I suspect that there is another Danley product that has lower cutoff around 150-200Hz, and this device is intended to be used with it. Again, this makes sense, but I'd slice it up a little differently.* I am not about to attempt to answer for Tom. If he is reading these posts he can speak for himself about your comments above.
-
>> From that Tom designed the basshorn and the correct drive units to
>> do the job as he saw fit.
Makes sense.
>> My point is that if YOU were in Tom's shoes and were asked to
>> design this sound reproduction device (if subwoofer is not the
>> correct term) then what EXACTLY would YOU suggest the
>> Lab Forum build.
Honestly, that isn't a reasonable question to ask of me. I can tell you what I would do, and that is all. To attempt to "put myself in Tom's shoes" would be disingenuous. I have already told you that I would use a midbass horn to cover the range down to 60Hz, and a direct radiator for the two octaves below that.* This is all I was trying to accomplish Wayne. I understood your comments about the shoot out to mean that you did not agree with some of the design choices made and I was just trying to find out what you, as a speaker designer, would have done differently for optimum reproduction in the range of 30-150 Hz, as was the desired target for the Lab horn. Which you have kindly done so below. I am not going to say that I think your design below is wrong, there are many ways to accomplish certain goals. I will say that I have done direct A-B listening tests of the Lab horn against many different bass reflex cabinet, some very similar to what you have described below and I preferred the Lab horn for many different reasons. AGAIN this is just my opinion I prefer bass horns over bass reflex cabinets, I also prefer lager over ale and blondes over brunets. I think this was also the general out come at the shoot since the two cabinets that were liked the most were bass horns not the direct radiators that were present, which I am sure were well designed fine products. Bottom line is that I thought Tom has done an excellent job designing the Lab horn and since you did not seem that impressed with the measured results that you may have a better deign in mind to accomplish the same goals.
*So again I thank you for offering the alternative design ideas listed below. I will be attending Lima and I will make sure to stop by and say hello.
TDM
I think probably there was some development time spent on the LAB project, and I think it would be reasonable that any project submitted for comparison to be given the same amount of time to mature. But I'll shoot from the hip and let you know the direction I'd likely take.
As I said, my design goals would be a bit different, because the subsystem components I would choose would be different. I'd employ midbass horns from 60Hz up to 300Hz or so. And I'd use midrange horns above that, crossing at 1.6kHz to compression horns. So my subwoofer focus would be a range that is exceedingly difficult to cover with a portable horn - from 60Hz down. If the basshorn could be built as a permanent installation, super. Build a large horn as an equiangular spiral under the floor or behind the walls. But if it must be portable, then it must use direct radiators because horns for the bottom octave are prohibitively large.
The choice of direct radiators wouldn't preclude the use up to the 200Hz crossover of the LAB horn, if this high frequency were required. It's just that in my application, I'd prefer to horn load as far down in frequency as possible, and crossover to direct radiators for the bottom octave where a portable horn would be too big. The subs would be somewhat versatile, since they would be individually contained in smaller cabinets. Each 18" woofer could be used individually or clustered together. That gives some versatility, and I like that.
For the direct radiators, I'd probably choose four 18" drivers in a bass reflex cabinet the same volume as the LAB horn, tuned to 15-25Hz. They can be contained in a single cabinet, but as I said above, I'd prefer to have them isolated from one another in individual cabinets for versatility's sake. I'd load them with JBL 224x series woofers or Eminence Kilomax, Magnum or Omega parts.
I suspect that this four woofer combination would generate about 135dB at 100Hz at one meter and at full power. This is about the same output as the LAB horn, and the alignment chosen would allow it to generate output a full octave below the cutoff frequency of the LAB horn.
Take care!
Wayne Parham
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: Solution indicated by conditions - TDM 05:38:17 03/04/03 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
