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Unique & Distinctive Speakers

Bose Acoustic Wave Cannon

A subwoofer with an attitude...an imposing 12 foot black tube, housing a 12 inch LOUDspeaker.

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That Bose subwoofer is actually just a variant on an idea that is about as old as audio itself -- there were plans for essentially the same thing in the first issues of High Fidelity or Audio (whichever was in Great Barrington) from the 50s. Roy Allison got his start working on the refinement of it. I think it started out as a quarter wave resonator and then became several smaller tubes of different lengths before ending up with the driver one third of the way down the tube.
(My memory of the details is hazy since I lent the first three issues to a fellow nutcase, and its been difficult getting them back -- they really are deeply fascinating.)
 
Nat said:
That Bose subwoofer is actually just a variant on an idea that is about as old as audio itself...
Click to expand...

I once heard one of these Bose units at a record store (suspended up in the air), and it easily filled the huge store with a lot of bass you could feel and hear. Later, I once was able to see behind the screen of a movie theater and I viewed a few large tubes such as these handling the bass. I seem to recall an article I read once that explained why the design works so well, but at a size/length penalty for larger drivers, thus making these more suitable for commercial applications.
 
A open tube attached to a driver will resonate at odd quarter wavelengths, and if you put the driver 1/3 of the way down you get the resonance of the whole tube, the short end, and the long end, so rather than one enormous resonance, you get a more distributed set. Add more tube of more lengths, and you get more distribution -- that's the idea behind Stuart Hegeman's very interesting speakers of the 70s, now being sold by someone in Canada, I think -- a whole set of tubes of diffferent lengths. It's also the idea behind Tapered Quater Wave Resonantors, though the tapering smooths the resonances somewhat. Its arguable whether or not it is the actual reason that transmission lines work, but that is a very complicated issue.
Resonances are useful for getting volume, but are obviously a disaster for smooth response, unless you do the Hegeman thing (and there you actually are sacrificing the really low end for smooth mid bass). So for a long time, when smoothness of response was the goal, and acoustic suspension speakers were the means, pipes were out of fashion. Then along cam SETs, and Bose and tiny speakers and subwoofers and suddenly one, two or three note bass became more congenial...
 
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The Ultimate by Transmission Audio

Cost = $2,000,000 USD

The system, containing 4 separate dipole Subwoofers, (seen in the middle), made from a total of 40pcs of 15" woofers, followed by 1 dipole panel per channel, each containing 24pcs of 8" units, in turn followed by 2 full MF ribbon dipoles per channel plus one HF panel per channel, containing a total of 68 meters of true ribbons, has a sensitivity of +100dB/1W/1meter and can continously handle 15500W with +3dB headroom. A total of 31000 Watts, equalling 146dB SPL. The system comes complete with its own poweramplifiers to match.

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But properly the only quality speakers a 14 year old girl would die for, maybe even cut the phone bill a bit :)

Not to mention all those Mac users.
 
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