Velodyne Digital Drive Series subwoofer in stereo

I'm no professor but it seems to me you can't 'miss' any of the bass if you've summed the two channels through the sub. Its all there, how can you 'miss' any? Has anyone really compared two subs run in stereo to two subs daisey chained together? And can you honestly hear any difference or do you perceive it? I just can't believe there is. A benefit to having two subs though is another matter. I know two different people running two DD-18's in their systems... from what I hear, I want to match my single DD-18 to a sister sub... holy cow! Neither runs their other then daisy chained and both are knowledgable people in the industry.

Two answer your question, I have compared my two ULD-12's running in mono and in stereo. There is a difference. Remember that the left and right channel may have different phasing when picked up by the microphone. The most extereme example would be where the mike picked up the signal 180 degrees out of phase. This would result in no signal when summed to mono, when in fact there is a completely different signal from left to right. When played back the summed mono would have no output while the stereo subs will put out the signal and the listener will hear the bass as picked up by the microphone.

Dear Spacekadet: Why I already say that you can loose music info. With a pair subs you have stereophonic sound reproduction that is exactly how its happen at the recording event.
Example, let's take a low drum that was recorded at left side of a music hall : if you have a dual mono subs ( left/right separates ) you will hear that drum at the left side on your audio system but if your subs are sum up ( left+right ) you will hear that drum at the center of your audio system.

Regards and enjoy the music.
Raul.

Possibly the difference between one or two subs is non-quantifiable. I certainly heard a difference when I added a second Vandersteen 2W sub to my system running in stereo. I believe I hear quite well the stereophonic effect of the low frequencies. The room certainly fills with low sound better than with one sub, and there have been no problems with nulls that I'm aware of. Currently I have ten 8" bass drivers operating and simply the presence of the additional drivers makes exceptionally deep frequencies audible. Previously, when I operated two subs (with six 8"drivers total) an incredibly low bass note was not even audible. With the addition of four more drivers it could be sensed.