I'm reviving this thread after years without a solution.
I don't know why this problem occurs and I can understand that it's not easy to fix (the first Mass Effect is very old, there's no surround sound by default on PC either, I don't know about Xbox...), but, if it's really that hard to fix, could you update to disable surround sound in the first Mass Effect?
Right now it's really annoying and the only solution is to manually enable 2.0 sound on the AVR or PlayStation, but then we have to re-enable surround sound for other games (including ME2 and ME3). It's not a very comfortable solution. However, if you enable 2.0 sound in the game itself, you save us from having to do this kind of "fixing" every time we want to play the first Mass Effect.
I know it doesn't happen to everyone, but in my case it's an accessibility issue. The problem of the volume difference in the SFX and the dialogues coming from the surround speakers gives me a slight headache after playing for a session. If the fault cannot be solved, I prefer to have a good Stereo than a defective 5.1 and disabling is the most comfortable option for everyone. As developers it only takes a few minutes and we, as users, do not have to change the configuration of our AVR/PS continuously.
Greetings.
