Have been investigating this area recently. I too like the labhorn setup, although I have never heard one. For my way of thinking, I don't really see the neccessity to separate sub-bass and mid-bass. A PA bottom end bin SHOULD be able to cover ALL of the low end, say from 200Hz down. For this, the labhorn doesn't go high enough, and I'm not overly impressed by the measured response lumpyness anyway - which seems to be a direct consequence of the too low Fs of the Lab12.

At this stage I am not convinced with the need to go quite as low as 20Hz, but certainly believe we should be trying for maximum performance to at least 35 or 30Hz, rather then the common 50 or 60Hz. To this end, I am currently working on a wide range bottom end bin which so far models fairly flat from 35Hz to 200Hz (block of 6), and will get a chance to prototype within a few months when shipment of the appropriate Beyma drivers turn up.

Cheers
Graeme

There is a simple reason for this, and it has little to do with the capability of sound systems. It is that the human ear just isn't very sensitive to pure tones lower than 60 Hz, and when the second harmonic content of a bass tone is increased in level the brain is fooled into thinking that the fundametal level has been increased as well. This meshes quite nicely with the latest research on the subject by variuos sources as published in the Journal of the AES, where it has been verified time and again that increasing the subjective psycho-acoustically perceived level of bass content is most effectively achieved by the alteration of harmonic levels and not fundamental levels of bass sources.

Chances are that when you have problems with kick drums it's not at 40 Hz but at 80 Hz. I've found that when bass levels are perceived as excessive, to the extent of pounding your chest so hard as to literally take your breath away, the bulk of the energy present is around 80 Hz, not 40 Hz. When you retune the drum higher what you're really doing sonically is pushing that all important second harmonic higher to where it is less offensive.

The woofer is intented specifically as a low distortion subwoofer, suitable for use a variety of cabinets, including the LABhorn. The proposed target specifications make it suitable for use as a direct radiator, bandpass or horn subwoofer. The simplest implementation is a 2ft3 to 5ft3 vented box tuned to 20Hz. It's most common implementation is likely a low-distortion, high-fidelity drive unit for the LABhorn, or other suitable bass horn.

I'll provide a head count to Eminence to give them an idea of interest in this improved MAG12 subwoofer. So please write to me if you are interested in this and I'll pass the word.

I've always thought similarly to what Bill said, in that bass horn must be very large to get under 40Hz and keep response flat. If the installation can be made permanent or semi-permanent, then the horns can be made large enough to reach below that, but for portable stuff, I've sort of concluded that 40Hz was a good lower limit for horns. Seems like between 20Hz and 40Hz, everything is pretty much from direct radiation anyway, whether in a horn cabinet or not. So I like the idea of having direct radiating subs and horns from midbass up, at least for relatively small sound production work like clubs and theaters and, of course, people's homes.

But if you can stipulate that several horns be used, then each one can be made a little smaller and still get the job done. For large-scale setups, that becomes an option. Or if the installation can be made permanents or semi-permanent, then you can really come up with some neat large bass horns. And then there's the reality that 40Hz is a pretty good goal for bottom end, and if bass is solid down there, it generally satisfies completely. 120dB between 40Hz and 80Hz sounds very powerful indeed.

Cheers

But I definitely understand the issue of $$$bucks$$$. I'm impressed when a twenty-something fellow is as techno-savvy as you are. It's hard to plop down the cash for expensive hobby projects, and the good stuff always costs a lot. You can really see this in auto parts and sound equipment. So kudos to you for using your intelligence to make up for your budget crunch.