WHat about four speakers.......

Mythtrip, it sounds as if you and Dr Amar G. Bose have visited the same concert halls : )

Honestly though, his published theory as to how he came up with the design for the original Bose 901's is very similar to some of what you stated above. The main problem with his design is that it uses multiple drivers and suffers from severe comb filtering. In effect, the design creates almost as many problems as it tries to address.

As Duke stated, omni's are capable of producing a very expansive soundstage but are also more susceptible to reinforcement / cancellation from room boundaries. If you can get a good pair of omni's properly set up, the soundstage is pretty amazing. I have a pair of point source ( one driver per cabinet ) omni's and they produce a soundstage that literally "wraps around you" and "engulfs" you on some discs. I have never heard any other speakers ever do this. To be honest though, the electronics in this specific system also play a key part in this as these speakers have not always produced this effect. This is true even though i have not altered their position over the course of many, many component / cable changes.

Dipole's aka "planar's", "stat's", "ribbon's", etc... are capable of doing this, but not to the same extent ( at least in my experience ). They do tend to sound far more open and less "congested" than what most "boxes" are capable of as a general rule. The problem with a dipolar design is that the rear wave is out of phase with the front wave, creating an instant problem with cancellation. In comparison, the specific omni's that i have radiate in a 360* pattern while keeping the signal in phase. So that you have a better idea of what i'm talking about, here's a picture of what they look like. The specs as published are VERY incorrect though, so take them with a grain of salt. The only thing that the manufacturer got right is that you need AT LEAST 100 wpc to drive these. I have two pairs of these with one looking like the picture and the other having a slightly different design.

All i can add to the above is that once you experience a system that has a very expansive ( wide, deep and tall ) sound stage, you will find it hard to listen to "boxes". They will, for lack of a better term, sound very "boxy". Obviously, some designs are better at "disappearing" than others, but much of that will also be up to the electronics that they are connected to. Sean
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see Dolby Digital 5.1 channel sound
see DTS surround sound
see DVDa multichannel sound
see SACD multichannel sound

All of these formats are competing for the multi channel music market (Dolby Digital 5.1 is mainly for movies).

Anyway, my biggest argument against multi channel music is all of the speaker cable or interconnect involved. Your either going to have to run some very long interconnects or very long speaker cables to 2 sets of speakers. This can have a serious impact on the sound quality of those speakers. Why would one want to listen to 3 premium sounding speakers then 2 speakers that were producing noticeably less quality of sound.

This dimished sound quality for rears is not as evident in movies due to the fact that most rear channel sounds are really not recorded terribly well. Most of the Movie sound comes from the L/C/R/ speakers.

KF

I agree with TWL. I think there is potential in multi-channel reproduction, but I have yet to hear it done "correctly".

I'm not sure this thread is exactly about quad... but that was certainly an attempt at this.

In my personal experience, I listen to (what I would like to call, if such a thing can exist) "4-channel stereo" much of the time. The only company I'm aware of that explicitly offers such a mode (5-channel stereo, just lose the center) is Adcom, and I haven't much enjoyed what I've heard or owned from them. I have an Acurus Act-3, which I purchased ONLY because it 1) will allow independent volume control over front vs. rear via a balancing adjustment, and 2) will allow me to hook everything up to it, HT (seldom-used) included. That said, I don't really like this unit much either.

I am definitely *not* a pre/pro expert (I try to pretend they don't exist) and that's the one place I always run and hide in this hobby... it's hard for me to select a pre/pro because all I really want is 4 channels (front + rear) with independent volume control to move the emphasis forward and backward, as needed. HT capability is also a nice thing to have, but in every unit I've researched, the HT angle seems to be all they are paying attention to, and good 2 or 4-channel non-altered playback is either impossible, or an afterthought. All the pre/pros I've ever looked at seem to display an enormous HT bias. I would rather have a pure 2x2 setup without all the delay and echo and who knows what these systems always seem to force one to use.

Are there any units out there that offer HT capability while offering a good 2x2 (stereo front + rear) mode without all the HT echo party/arena/stadium/jazz club hoo-ha? I'm ignorant in this arena, let that be said. Last time I looked, I was very, very discouraged.

I think I should chime in here, all of the above makes perfectly good sense and that was also the reason why I refrained from any experiments into that direction until I heard that Quad's Peter Walker had a speaker setup ( a wall of his stators) not unlike the one I had arrived at PLUS Quads (don't know how many though) arranged along the side (not back) of his listening room. When I had managed to obtain a pair of ESL63 from ebay at a very good price I started experimenting and finished placing the speakers at right angles from the main speakers halfway between them and my listening position fairly close to the side walls, firing at each other and giving them a dedicated amp and preamp, fed from the tape out of my main preamp, a Jadis 200. I have the dedicated preamp close to my listening position, so I can dial in the exact dose of side information for every piece I am listening to. The dialing in has to be done in very, very tiny increments and what is most important, seperately for the left and the right side, in order not to ruin sound stage information and the placement of instruments and voices therein. However if done right, it will give back ambience to overly dry recordings and add width and depth and a sense of immediacy to good ones. I will never go back to the classic setup and found this to be a great step forward in my personal enjoyment of my rig. However the step between enhancement and ruin of a presentation is very slight and it is frankly even more difficult than properly dialing in a subwoofer. I also think, that it is essential with such a setup, that main and side speakers should be of the same make, or at least similar in their voicing and characteristics and all this should not be attempted for the very reasons given above, if the auxiliar side speakers cannot be dialed in exactly for each LP, Cd or master tape being played. Cheers, Detlof