Really? The game is unplayable because sound effects and dialogue are also coming from the rear speakers? I mean, it sucks and I went with headphones for the majority of my playthrough as a result, but unplayable? Come on.
To me the loudness issues are much more of a problem, to be honest. The mass relay transition screen is so unbelievably loud that I had to mute my AV receiver every time. The same goes for gunfire (had to set sound effects volume to 40% to make it somewhat tolerable), and even the end credits song is at least 10 dB louder than the in-game audio. What a mess.
They are not 'also' coming from the surround speakers, they are only coming from the surround speakers. This means that all dialogue in cutscenes are coming from behind your back only and that makes it unplayable. Forcing audio output to stereo to make it listenable is quite simply unacceptable.
