It is too bad that receivers are not more flexible. Why can't you have both height and width at the same time? It seems like height and width would be more beneficial in most rooms than the rear surround channels. So why is it not possible to use the channels of amplification in that way, if there are 9 channels on the receiver? I thought that Denon allowed 11.1 if you add an external amp for the height or width. This is a terrible waste of an external amp. Ideally, one would want to add extra amplification for the front left and right speakers. This would free up the extra channels on the receiver for both height and width speakers, but I think that the receivers are not set up to work in this way.
The newer line upper end model AVRs from Yamaha allow you to do somewhat what you ask but with their proprietary DSP Soundfield processing,different from Audyssey which is not part of their package. Back a few months ago I bought an RXA(Aventage) 2000 which allows one to use external amps for the front and center along with all the other channels which I have, via the 7.1 pre-outs, connected to outboard amps anyway and this allows me, along with PL11X to run a constant 9.2 soundfield(with the elevated front presence channels, similar in positioning to the height channels) at all times. The top-of the-line 3000 models feature the option of even a further additional two-channel hook-up complementing the rears to create a constant 11.2 configuration. In each case the addition of an external amp, connected via the pre-outs, frees up the internal amps in the AVR to connect these additional speakers so the outboard amp is being used the way it should be.
To tell you the truth, personally, I prefer the Yamaha soundfields, particularly those that cater to movies because they expand the soundstage to make it sound like you are in a larger space than you really are and are fully adjustable to your particular taste and acoustics of your room.
