phillip holmes wrote:
I mean below 40Hz.  And the early stereo microphone techniques were at 
least 10' apart.
I have "full range" speakers, but I added subwoofers because the room 
volume was too large.  After adding the subs, I noticed less of a problem 
with standing waves (but created other problems with crossover between 
the subs and the fullrange speakers and distance between the two--very 
hard to get right).  A friend pointed out that "sub" woofers should be 
pointless since they are "below" bass.  But I never felt like I could 
hear the hall without subs.  Concert halls add as much character to the 
bass as the midrange and up.
Phillip
The wavelength at 40 Hz is about 25 feet. That means that subs 10' apart 
are separated by less than half a wavelength. Therefore, your sound should 
be at least as good with one subwoofer as with two.
There's plenty of signal available in the octave below 40 Hz with the 
right material. I've a monaural recording of pipe organ that shakes the 
place with its 32-foot stop - 16 Hz fundamental.
Mike
--
mrichter@xxxxxxx
http://www.mrichter.com/