When installing a 990/7700 combo does it matter which 5 channels you use??? In other words I am running 5 speakers and a sub right now. Front left and right, center and 2 in the rear. I can't remember which outputs I used, the rear or the sides. If memory serves me correct, I used the rear surrounds and not the side surrounds.

Any difference??? Thanks.

I'm pretty sure you have to use the side surrounds...but I'm not 100%...check if you have a signal with dolby digital or dts material

Doesn't make sense since before 7.1 even hit, it was only rear surrounds. Now they want you to use the side even though mine are in the rear.

You need to use the side surrounds - the rear surrounds are the additional two channels that give you 7.1. This may seem odd since we often thought of 5.1 surrounds as being in the back, but they were actually intended to be along the side walls (as they are in movie theaters). The back surrounds are a refinement of the single "back" speaker introduced by Dolby Digital EX and DTS ES.

Thanks. What would be the difference to my ears??? When I get home tonight I will check but like I said, I am sure they are hooked up using the backs and the sides are empty, used balanced connects. It sounded pretty good to me. Any improvement will be welcome.

If you have the backs connected and are getting sound, then you have the sides enabled and they are sending sound to a dead end - basically, you are throwing away at least half (possibly more like 2/3rds or more) of your surround information. Move those pre-amp outputs from the back to the side and set the back surrounds to "none" in the 990's menu.

I will give it a try and let you know. Thanks so much again for your time.