Newman
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Actually, I described it inaccurately. The multi-sub technique, as explained in detail in my book, attenuates some modes (odd order 1st & 3rd) while amplifying even order (2nd). All modes are amenable to attenuation by equalization, but normally they are in disarray. The multi-sub arrangements in rectangular rooms create order, so that listeners can find locations where the bass is similar. Once done, the remaining modes - certainly the amplified ones - can be equalized, but in a way that affects several seats similarly. Figure 8.15 from the 3rd edition illustrates the principle quite well. Equalization is still required, but the situation is much more orderly, more predictable. Missing from this is system efficiency: subs in corners win.
View attachment 158469
Obviously non-rectangular rooms need different approaches. Active sound field optimization works extremely well and has the additional advantage of significantly increasing the system efficiency. See Section 8.2.8.
Thanks, fascinating. I notice the above diagram includes several subwoofer layouts but not the "quarter width points along front wall" technique from pg 14 in your 2002 paper. Has that layout fallen from favour?
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