Dear Truthseeker: +++++ " This whole stereo sub thing is nonsense. Hardly any info there. Hardly heard. " +++++
I think that you have a misunderstood of what happen in a real stereo subs integration to any audio system:
First, we choose the crossover frecuency ( say, 80Hz ) in the high/low pass filters. What this means?
That the main speakers will handle frecuencies over 80Hz and that the subs handle below 80Hz.
Normally, the self electronic subs crossover is a second order design ( 12db per octave ), this means that the subwoofers will work with frecuencies as high like 200Hz and now in the whole subs frecuency range will be stereo information.
Second, the subs reproduce not only the fundamental frecuency but their harmonics too where we can heard the left right info.
Third,it is not totally true that the CD recordings has only mono low bass. One of the CD advantages is that there is no problems for to record left/right low bass frecuencies ( in the LP is different ) and that's what the CD industry is doing: taking advantage of the CD medium.
Fourth, when you attend to a classical music performance you can heard bass sound coming from the left /right side of the hall, example: bass drum to the left and double bass at the right and this is exactly what we heard/feel when we have two subs in a stereo way at home.
Dear friend, I respect your opinion and that was mine.
Regards and enjoy the music.
Raul.