I would like to upgrade my old recevier and speakers to take advantage of the surround sound in DVD movies. I have read that most aurround receivers can play 5.1 sound without the sub and center channel by blending the center channel and sub into the front speakers. Is this correct? If so how is the sound?

My main interest is in music (95% of my usage) so although I would like to be able to take advantage of the 5.1 sound in movies it is not my top priority.

My thoughts right now are to upgrade my receiver (any suggestion for a $500 or less receiver), get a pair of surround speakers and then maybe upgrade my mains and/or add a center channel or sub.

On the subject of surround speakers how much difference do the dedicated surrouns type speakers make above ordinary small bookshelf types.

My main speakers are 12 year old Advent Prodigy Tower speakers. Anybody want to comment on how much say a M40ti will improve the sound (mainly interested ni the music aspect). Also if I am gonig to upgrade the main speakers I think for my interests the money would best be spent on a good tower and forget the sub at leat initially. I would like to add a center speaker eventually.

Also keep in mind that my movie listening is mainly done at night with the kids in bed so its low volume level.