Originally Posted by trek737
Any opinion on the multiple subs?
Not Mike, but an owner of Aerial 7Bs, CC3B, and multiple subs, in a smallish theater with definite modal cancellation problems. At least those were problems until I went with multiple subs. Harman (Welti, et al) is right!
And by multiple subs, I mean reproducing the bass <80 Hz as mono from multiple LF drivers. To test the theory, I first used my mains as virtual mid-bass subs (30-80 Hz) and filled in 15-30 Hz with my SW-12. The 4 virtual subs were tuned with a BassQ processor, which effectively cancelled the modal nulls. Final tuning was done to taste with the PEQ in the SSP-800. But in the end, pushing the mains and surrounds with movie soundtracks was stressfull on the woofers, so I just recently changed to using 4 real subwoofers (Hsu ULS-15), which improved the headroom some 10 dB. Detals of the BassQ exploits posted here
and the current system update in post 140
of the same thread.
Thus, you may have seen my beloved SW12 offered at Audiogon--the one in black ash. I was faced with trying to find 3 more, or selling it and buying 4 new ones. Even though there's a bevy of SW12s at Audiogon, they are not nearby, and not in the same finish. Painting the rosewood black would be a sin!
When I saw a pair of preowned 9's for sell it got me to think that with my fairly large size room that the 9's might be a better match. My 7's do a great job but, like most I guess, I am always looking on upgrading my system to get a even better listening experience.
Not sure how the 9's would make any difference in a multiple sub system, unless it was your thought that the 9's could act like two subs by covering the bass spectrum. They could if you did the same bass processing trick I did--to distribute mono bass to both of them. But if you run them in stereo, or as part of a 5.1 system, then the bass will not always be coherent, and that diminishes the effectiveness of the Harman multi-sub concept.