This is an interesting subject... but it makes more sense when you consider it in historical context.
Long before there was DD 5.1 surround sound existed in the form of "4-channel".
A four channel system had one pair of front speakers and one pair of rear speakers.
Then, when 5.1 surround came along, even though the speaker location is specified as being more towards the sides...
People still sort of thought of the SURROUND speakers as if they were "in the back of the room".
More specifically they served the purpose of "reproducing room ambience" and "playing things that occurred behind the listener".
Then, when REAR SURROUNDS came along, they were generally seen as "filling in the space way at the back of the room".
NOTE that there is NOT officially an option to have "one pair of surrounds way in the back".
(Most AVRs and processors will not
allow you to configure rear surrounds unless you have side surrounds.)
If you have a 5.1 system then you have surrounds; if you have a 7.1 system you have surrounds and rear surrounds...
You CANNOT specify a system with rear surrounds but no side surrounds...
(In other words those rear surrounds are considered to be intended to be used IN ADDITION TO surrounds rather than INSTEAD OF surrounds.)
- MANY older recordings were actually recorded in 5.1 (even long after 7.1 became available)
- So MOST older movies are actually in 5.1
- The rear channels tend to have little priority (only for stuff "way far in the back")
- Because of the way PLIIx and the DSU work, when used with two-channel content, they also tend to put very little in the rear channels
Because of this most people I know would consider the "hierarchy of how important channels are" to be:
- FRONT LEFT and FRONT RIGHT -
CRITICAL; most important for stereo music
- CENTER CHANNEL -
CRITICAL; probably most important for dialog; equal to FL and FR for music
- SURROUNDS -
SOMEWHAT IMPORTANT; less important than "mains"; less critical of things like speakers and amplifier power
- REAR SURROUNDS -
NOT VERY IMPORTANT; probably not terribly critical at all
- HEIGHTS -
SORT OF SPECIAL PURPOSE; usually used occasionally for special effects and not much else
(really cool when they're used... but often not used... or not used much.)
This is why a lot of people will use a big pair of towers in the front...
And a big center, although not necessarily with a big woofer, for the center...
And smaller speakers for the surrounds and back surrounds...
Note that, if you don't have Height Speakers, then you won't have stuff happening above you...
And, if you don't have Surrounds, you basically have "stereo with a Center Channel)...
But, especially in a smaller room, and especially if the room is not terribly deep, Rear Surrounds aren't especially important...
And, if space is an issue, just omit the back surrounds, and put your SURROUNDS back a bit further.
And, of course, with a 5.1 or 7.1 or 7.1.x system, you probably have a sub (or front speakers with "built in subs").
I'll preface by saying I'm aware I don't quite know what I did (or why I decided what I did), but I'm looking for help sorting it all out:
I finally moved to a home that gives me an opportunity to better situate things to listen to DVD / Blu-Ray audio for music listening purposes. I'd had floor speakers for my fronts for some time, but had some smaller speakers that were sufficing for surround. When we bought the new house, I purchased an additional set of floor speakers to put in the rear so that they were capable of delivering the same quality sound the fronts were delivering.
Having done all this, I decided to keep the existing smaller speakers, purchased stands, and set them up either side as surrounds.
What I feel I'm finding at this point is that my XMC-1 system appears to be delivering so much more content to the surrounds that the rears don't really seem to come into play.
If it seems as though I didn't quite know what it is I was trying to do, that might be a bit because I probably didn't know quite what it is I was trying to do - or how it played out in the real world. To my naive notion of what's happening, it seems as though some of the purpose of rear and surround are somehow reversed, and it's almost as though I should have much better surrounds than I should have rears. When I was listening to 5.1 audio this way before, the "rear" sounds just seemed wrong. All seems find for movies (although the surrounds really seem to need to be rolled back).
Conceptually, I just feel like what I was expecting out of a music audio notion is just totally wrong when it comes to the AVR notion.
I'm likely not stating this properly, and I accept if that's the case. I felt like 5.1 audio mixes were done expecting the same level of performance from the rears as from the fronts. It is with that premise in mind that I'm confused as to what I'm hearing - what the AVR is delivering.
