[clpetersen]

Originally Posted by chessman

There are some pre/pros that will let you redirect LFE to the mains, but I would advise against it. Assuming perfect integration of the stereo subs (which takes an active cross-over and a small miracle), the impulse waves of the stereo subs will match the mains. Actually, they are probably in phase but delayed by one of more cycles (due to group delay in the subs), so there is still smearing even though they look in phase on a graph. To make matters worse, the LFE track is added sound under 80 H (the "boom track") that has nothing to do with music. The fix is to send the LFE signal to a third sub while telling your pre/pro that your mains are "full range" and further telling it that your sub is twelve or more feet further away from the listening position than it really is. The pre/pro will start the impulse wave 12 milliseconds early, which will be negated by the group delay inherent in a thirteen inch diaphragm, with the net result that the impulse wave of the LFE arrives precisely when it sounds best. Now you see why I have three subs with an active cross-over running two of them and a pre/pro sending LFE to only one of them.

Nice write up, thanks. In our set-up, we use REL subs which allow the full range signal from the mains as well as an LFE (".1") input, which are summed by the REL. I have tested this using test tracks and it does seem to work well enough with the active crossover in the pre/pro. However, I lose the ability to individually tailor the phase delays between the mains and LFE output. Any thoughts? It seems that placing the subs 12 feet back (electronically) should work. Will try.