"something much cooler. take the main outputs and split them using y cords with the subwoofer. this is assuming that your main speakers can take the 'large' setting. then turn the sub woofer off on your receiver. now hook up the two subwoofers. you will get stereo from the subwoofers and this definitely works."
I assume by y-cords your suggestion is to hook up the subs in parallel with the front speakers via an additional set of speaker cables, connected to the high-level inputs of the two subwoofers from the receiver's main speaker jacks (or, alternatively, from the speakers themselves). This would indeed get a signal to each sub, but it begs the question of which type of installation is the better. If your goal is to get a stereo signal to the subs, okay, or perhaps you're inclined towards REL's arguments of sub/main matching. I tend to find in most situations the standard installation methodology of feeding a powered sub via interconnect to work the best, as (1) the main speakers are freed from the onerous job of producing low frequencies, particularly in HT where bass frequencies can be accentuated, (2) bass is handled more smoothly in the transition from sub-to mains when crossed over, instead of the overlap otherwise produced (look at REL's herculean approach to this in their crossover design, and then compare with the typical powered sub's minimalist approaches), (3) stereo bass is a bit of a misnomer anyway, as the frequencies at which a sub operates are of such a long wavelength that the ear does not distinguish them differentially, and (4) the main amplifier is also freed from the need to produce bass in the main speakers, leaving more power available for musical peaks-a traditional advantage of bi-amping.
Admittedly some folks will probably take umbrage at the declaration that one does not hear stereo bass. However, it is not solely my conjecture that given an approximately 80 Hz or lower signal the ear has a good bit of trouble distinguishing location. Try a little experiment, if you will- play a 1/3 octave tone centered at about 40 HZ or so, and see how (assuming the tone cuts off quickly, and the sub does not produce higher tones through distortion, cabinet resonance or other spurious means) difficult it is to locate the source of all that bass.
Mind you, I'm not saying that multiple subwoofers in a system cannot be used, albeit carefully, to both smooth response and increase dynamics/lower distortion. I use dual subwoofers in my own strangely-shaped room, as that works best. But it's not for stereo imaging of my subwoofers....
-Aerlith
