Deep_333 wrote, " Duke, Can you name the popular opinions among sub manufacturers on how they think it should be addressed? Of course, more subs a.k.a an array of 4, 8 or 16 is great for business. But, are there other opinions out there?"
Setting the controls on the subwoofer amp correctly matters a lot. If you’re doing it by ear, first set the level, then the frequency, then the phase. Then cycle back through again a few times. This order is progressing from "makes the most difference" to "makes the least difference."
(Setting the level correctly is particularly time-consuming. Equal loudness curves indicate that a 2 dB difference at 40 Hz is subjectively comparable to a 4 dB difference at 1 kHz, so precision in setting the level really is called for. This also explains why smoothing the bass response pays unexpectedly large subjective dividends, as the ear is arguably doubly sensitive to peaks in the bass region.)
Careful positioning of the subwoofer and/or listening location is beneficial. One particularly effective technique is the "subwoofer crawl". Put your subwoofer in the listening chair and crawl around the room until you find the location where the bass sounds the best. Place your subwoofer there.
Bass trapping or other methods of low-frequency damping improves the bass smoothness everywhere in the room by reducing the magnitude of peaks and dips.
EQ on its own is most suited to smoothing the bass in a small listening area. This is because that roller-coaster pattern you mentioned typically changes significantly for different listening locations around the room. Of course bass trapping and EQ can be combined with other techniques.
A distributed multi-sub system, or distributed bass array, smooths the bass throughout the room by reducing the magnitude of peaks and dips.
A planar bass array consists of a rectangular array of four subwoofers on or in the front wall, with a similar array on or in the rear wall. The symmetrical rectangular configuration minimizes reflections in the horizontal and vertical directions. The subs in the rear wall are delayed such that they cancel the output of the front subs when it arrives at the rear wall, so there is theoretically no reflection in the front-to-back direction. I have no actual experience with this approach.
"Of course, more subs a.k.a an array of 4, 8 or 16 is great for business."
I’d probably make a lot more money selling a single big sub for the same price, as the labor cost to build four small subs is roughly four times the labor cost to build one big sub. I went with four small subs (credit to Earl Geddes) after spending many years trying to develop a single subwoofer "fast enough" to keep up with Maggies and Quads. The solution was to focus on room interaction, because (imo) that’s the biggest problem.
" As far as the manufacturers coming up with a flat response (Rythmiks, HSUs, SVS, etc), Is it just a "statement" that they are competent enough to come up with a flat response? "
I am sure those designers and others have worked just as hard at solving the problems they believe matter most as I have. And they are probably better at hitting their target(s) than I am at hitting mine: You mentioned 4, 8, or 16 subs, and my 4-sub system would be outperformed by 8 or 16 sub systems.
Regarding the "forest of subwoofers" issue, often at audio shows nobody even notices the four small subs sprinkled around the room until they are pointed out. In many cases as the number of subs goes up the size of each sub can correspondingly go down, and in some rooms it is practical to place small subs atop bookcases or on shelves.
Tomic601 wrote: "Duke you really should look at the wave photo I emailed you long ago"
I vaguely recall it, but couldn’t find it when I looked again just now.
Duke
