i think our speaker systems and rooms ideally ought to compliment the media we choose. otherwise we compromise our signal paths or sources.
sooooo, i have a purpose built 2 channel room with a built in shape and built in diffusion for 2 channel media, then a separate 9.3.6 multi-channel Dolby Atmos home theater room for movies and multi-channel music. my home theater room is more compromised acoustically, since i'm not chasing reality and it's my lesser focus. who knows how that 'popcorn' movie is supposed to really sound? and i have my 2:35 10 foot wide picture to distract me anyway.
i play the media where it belongs.
a center channel in a 2 channel room is going to be a trade-off somewhere for 2 channel media. especially for analog. unless you have a 3 track tape deck and appropriate tapes. but we all make our choices. i love my Trinnov dsp, but i keep it where it belongs.....far away from my 2 channel room.
even if i was 2 channel digital only, i would not dumb down my Wadax digital to feed a center channel.
Either you are bothered by the inter-aural crosstalk caused by 2 speaker systems or you are not. I really like 2 channel audio recordings and overall prefer them to multi-channel recordings. They have all the information I need in them to create the soundstage I'm after. The problem with using just 2 speakers is that it significantly damages the signal that actually reaches your eardurms because of inter aural crosstalk that is extreme in the case of a center panned phatnom image. Usually there's a centerpiece performer that's panned center, so that's exactly where I don't want that to happen. Because that interference pattern is so strong, it's very diffucult to mask it with room reflections without seriously compromising the imaging and tone overall. My experience is it just can't be done to my satisfaction. Nature never has two sound sources playing nearly the identical signal at the same time so much as to make it sound like a single sound source coming from between them.The 2 speaker phantom center totally works if you're right between the speakers but it has a unique sonic effect that is peculiar to stereo systems. You either like it or you don't. I don't, so I see standard 2 speaker setups as not suitable for sweetspot focused listening, but better for party mode, moving around the house, dancing, or sitting off axis and listening casually. Just enjoy the spacial effects but don't get caught up in analyzing the sounstage accuracy. There's a limit to what it can do although you can learn to hear through the error, similar to looking at a stereoscopic image when a lot of light is bleeding across into the wrong eye. The ghost side images are there messing things up but some people can learn to ignore them better than others.
2 speaker setups are an audiophile tradition, and people have come to want to hear that crosstalk interference as a feature, a historical artifact of reproduced home audio. If that's what you want then that's really easy achieve. I dont' like it so I have to make efforts to hear what I want to hear. A physical crosstalk barrier works beautifully but it's not a practical setup. Recursive crosstalk elimination schemes also work but to my ears they alter the signal purity too much, adding their own audible and undesirable artifacts. Dolby upmixing is interesting too. I should experiment with it some more but so far I feel it's a bit too agressive, although usually better than just using two speakers. I do not understand how it separates and steers the sounds to new channels. I just use very simple channel mixing
Regarding signal purity with channel mixing, I can digitally mix a left and right channel, and then mix the inverse of one channel back in, and that channel disappears entirely. There is no hint of it left, and no mark on the original channel. I know this because If I then mix in the inverse of the original channel I get pure silence. The digital sigal is comprised entirely of zeroes. Digital summing and subtracing of signals is extremely pure as long as you don't clip anything. I'm pretty sure that no passive network in any speaker can be inversed with that degree of purity. So yes, I'm adding a step to the signal path, but if it's degrading at all, it's orders of magnitude less degrading than what's happening between the amplifier and the speaker drivers in even the very finest speakers with a passive network. It's not something I'm going to be hear and be bothered by. There is a way to implement my method of crosstalk reduction and center channel derivation without any channel mixing. It can work with a standard 2 channel system - pure analog, whatever. It would just be a type of speaker and would present a normal load to a 2 channel amplifier. I did a quick experiment by jumbling some speakers together and heard it work. It was an ungainly mess but proved the concept. I might build a speaker for myself using this method just for the convenience of not requiring the signal mixer in my playback chain.