My theater room was wired for 7.1 when built, and have been using 7.1 while watching movies in one form or another for the the last 3 years. The HD-a1 has only 5 analog outs, and since neither it or the 990 can apply dsp to them to create 7.1..... split the surrounds to the rear surrounds for psuedo 7.1 on the Toshiba's outs. The question is, I have been thinking about purchasing dual passive cylinder subs, and if one channel of the amps (4 crown xls-402b's) is freed up, don't have to find another amp channel to drive a 6.2 setup....was thinking about just running the two rear surrounds in series with the surrounds and using the 6.1 dsp formats instead of dplixx. Another added benefit of freeing up a channel on the amps is it allows an easier relocation of the amp and sub(s) to the front of the room between the fronts, which should help with blending of the bass between the fronts and the sub(s). Will probably test 6.1 vs 7.1, to see what I could be missing, but it is not really a fair test because it does not include the bass gain of going to .2 on the sub side (at least I hope the bass improvement of .2 vs .1 will be noticed), but at least it will give me some idea before purchasing two subs. Any thoughts on 7.1 vs 6.1 or 6.2...anybody compared them using the 990 in their setups?

thanks