I have a general question about surround sound.

What is the big deal about multichannel music? I see where many of the new SACD's are multichannel. Does this make the recording seem more lifelike? When we go to a concert, the music only comes from in front of us. Isn't that the purpose of the two speakers in our stereo systems? Why do we need two behind us? I understand about ambient noise, reflections, etc. It just seems to me that music is more accurately reproduced with two channels rather than multichannel. Could I please get some feedback and whether you agree or disagree with me and why.
I guess I kind of feel like you are under estimating reflections. A reflection can sound as lifelike and be dynamic as direct sound. To me, that is the point of multichannel music. Although I have not adopted it yet.
I love two channel also, but multi-channel can be good if it's done right.
A lot of multi-channel mixes are stupid, putting instruments and singers behind you. The good ones put you in the audience, like at a live performance, but that does not mean it isn't accurate; the fronts do the same as always, the rears add the ambience of the venue. You hear the sound of the room, which can be good or bad: concert hall good, arena bad!!
Actually, at a live concert, the sound comes from all around your head through reflections. The directional cues that you relate to come from the front only. The richness of the acoustic experience relies on accurate rendition of stage depth and reflections in the listening environment, usually a larger one than a home. Incredible expense and art have gone into designing concert halls to provide the best acoustics. Two channels can only present a window into the direct sound with perhaps some stage depth. If you use multichannel to deliver the appropriate sonic environment, than yes, it is superior to two channel. Multichannel has the benefit of stabilizing bass and midrange and reducing summing and cancelling nodes, making these tones much more rich and believable.
It is impossible for two channels in front alone to present a complete acoustic experience and this has been demonstrated through psychoacoustic research, although some audiophiles cling to the notion that somehow two channels are always the best.
The thing is, when you get your 2-channel right, you do feel enveloped by the music - in the correct way. That is up to us to discover the tweaks (room treatments etc) that get us there. With multi-channel, you are at the mercy of the mixing engineers who want to "Whizz-Bang" listeners with things like tambourines in the rear channels.
This is like one of those questions about "the best" or "who is right" it's all Apples and Oranges to me. I've kept my stereo system in the ex-family room and placed my surround in the living room with the TV.

Multi-channel sacd's can sound phenominal (Roxy Music "Avalon") or horrible (The Police - any). The classic's have the same problem. I would never give up my multi version of Orff but there are many others where the ambience is mixed ridiculously low.

Yes, I listen to "Dark Side ..." on the stereo system BUT I also enjoy the quad type mix on the surround every now and then.
I detect the fundamental knee-jerk reaction to anything but two channel stereo. The ambiance of the recording venue is not very well reproduced by two channel. A number of audible cues are present on stereo recordings, but to reproduce this "other dimension" of sound, added channels are required. How many and what to pump through them is another issue, but the fact remains that to come out with the two statements that music only comes from the front of the hall and that we only have two ears so why more than two speakers is simply wrong.
Jkphoto wrote: "The thing is, when you get your 2-channel right, you do feel enveloped by the music - in the correct way."

It may be satisfying but it can never be correct. The reflections generated by your listening room are not anything like the reflections/ambience of the performance site.

Here is what I wrote for a previous posting.

Multichannel discs, and why.

There is a limited selection of Multichannel discs, and some controversy regarding the merits of multichannel. Certainly there are some inferior discs, but there are also a few that are superb, and demonstrate the potential of the medium to far surpass stereo.

Here are my thoughts on the subject, and I hope that others will offer similar info, perhaps with regard to pop/rock music where I am completely ignorant.

1. The most suitable type of music for multichannel is a small group of musicians like a classical quartet, or a jazz band. The recording can place one instrument, more or less isolated, in each speaker. This has the effect of transporting the musicians into your listening room, rather than projecting you into the performance space. The result is striking. The best examples are Tacet DVD-A discs of chamber music (Mozart Flute Quartets is a good one) and Warner DVD_A "The Bluegrass Sessions...Bela Fleck.

2. "Antiphonal" music is composed with two or more separate groups of musicians in mind, and is a natural for multichannel. A Sony disc of E. Power Biggs playing four separate organs at the same time in a cathedral in Freiburg is a good example. The music is Bach Toccatas and Fugues, and his performance, where the musical phrases are answered back and forth between instruments puts an interesting new twist into these old war horses. The music is very antiphonal, but we never realized this because you usually get to play only one organ at a time.

3. A Telarc SACD, "The Sound of Glory" illustrates another aspect of multichannel. This is a performance by the Mormon Tabernacle Choir, 400 voices strong, and backed up by what must be the mother of all organs. It's a huge soundstage, and it takes at least five speakers and several powerful subwoofers to do it justice.

4. The Sony disc of Mozart Sinfonia Concertante (Midori, violin and Nobuko Imai, viola) is an orchestral piece which places a significant part of the orchestra (not just ambience)in the rear speakers. This troubles some listeners, who are used to hearing music from a distance of 100 feet or more. However, for anyone who has played in an orchestra, or sung in a choir this perspective is very realistic, and certainly more "involving" than straight stereo.

5. Polyphonic music, where there are about ten musical lines going on at the same time benefits from multichannel which permits better isolation of the different parts. Teldec DVD-A Chanticleer Magnificat (Gregorian Chants) is an example.

6. Last but not least there is some music that just asks to surround and roll over you like a wave. Of course the example is PentaTone SACD of Rachmaninov Piano Concerto No. 2, famous as the world's most effective seduction music.
It's a big deal in that, it may offer the same amount of upgrade to the soundstage that stereo offered over mono. Does it do that at this point and time?, on some disc's yes.

I think that down the road (could be a good while), your going to have many new disc's come to market that use the multichannel format to it's fullest potential..that is: music that should have sounds that come from everywere in an unreal manor as you mention..A lot of new-age/trance/rock and that type of stuff will use the format with great results. Recordings that only need to maintain their up-front soundstage with only hall/room ambience will benefit from a discrete center channel, not the fake one we must use in our two channel setups. The rear/side speakers will provide the reflections for these recordings.

All that said, I have been playing around with different multichannel setups for a couple of years now and have formed a few opinions. My first try in a 12X17 foot room only worked to some degree if I used the long wall. The short wall setup always placed the rears in poor positions. The long wall setup (my listening position had to be against the rear wall) was much more real sounding but did not allow for the rears to be behind me so was still not first rate.

My second system try was in a much larger room 23x27 feet, this room is a dedicated room and is setup friendly with little to no WAF..now I was getting some place as far as speaker placement with no need to tweak speaker distance/delay/height and types used for rears. Still had a small problem though, I also wanted to watch Dvd's on my large RPTV in this system..this stuck the tv in the middle of things up front with a large center speaker on top of it which was to high IMO but did allow vertical placement with a tilt down towards the listening position. I used it this way and liked it a lot for a short time.

Then I had a brainstorm, get rid of the RPTV and get a projector..kill two birds with one stone, no large TV to muck the sound up and I could place the center speaker on the floor, I'm happy to say that if you have a large room, no WAF and don't mind spending a ton of money you to can reap the benefits of multichannel music.

Now if all those recordings would just hurry up!!!

I share your sentiments on surround sound

two channel done right can be phenomenal
spend the money there not on multi

multi channel smears the image unless it is set up perfectly and with a recording which actually incorporates the spatial relationships of the room. very few recordings are done true multi channel outside of the big budget action movies. WHo wants a boom boom room for just that? What you typically have in a multi channel recording is just mixing of multichannel info into 5.1 channels and no ambience or hall dynamics. One rare example of good multi is the last track on the Eagles Hell Freezes Over dvd - one singer per channel. String quartets or jazz trios should be recorded well in a 5.1 setting, but typically are not. Most 5.1 is very old historical (best seller back catalog stuff) two channel sources.

I just don't understand home theatre

more is not better

but it's a great way for people with older stereo systems to feel like they are actually missing something and get the upgrade bug

and you can impress your friends with psuedo imaging

The type of image that audiophiles love from stereo does not sound like anything you may hear in a live venue. Many audiophiles have given up, I think, on reproduced music sounding in the home like the real experience. Focusing on attributes of sound reproduction that are kind of inward looking, as though sound systems were to be compared solely to other sound systems, they strive for qualities that are not there in the real thing. The whole notion of being able to differentiate between musicians within an orchestra is one of these attributes sought by audiophiles. Unless sitting very close, most orchestras, except for the times the music demands a soloist or that only one section be playing, sound way more homogeneous, at least to my ears, than what audiophiles cherish. The hall ambiance is only hinted at in two-channel reproduction. Again, the whole thing hinges on what will be done with the new technical possibilities at hand. If it is anything like the production of stereo recordings, you can rest assured that it will be extremely variable. Thinking that only two channels are required is like hardening of the arteries.
The hallambience can be much more than hinted at IMO. As my system has "matured" with room treatments, cables, power-line conditioning,equipment isolation, speaker placement, tube selection etc ,,, hall ambience has come out to an astounding level. So much so that seated anywhere close to the sweet spot, you do feel surrounded by the music.
Your a lucky man. It's amazing that something as remote as equipment isolation would have an effect (placebo, maybe?) on ambiance. I maintain my point that anyone so enslaved to two channel would have been equally enslaved to mono. Audio of the high-end persuasion is going nowhere fast since there are too may sacred cows and belief in voodoo.
Just a clarification ... I am not enslaved to 2 channel, or mono - not sure what I said to give that impression. I indeed have a surround system and listen and view in multi-channel. I also listen to 2 channel. When I first installed everything, as one example, I preferred to listen to the Eagles Hell Freezes over in surround. As my system matured as described before, I can now say that I will listen to it in 2 channel as well. And if I am doing normal CDs they are MUCH better after all the work.