Recently, I've been messing around with compression on my drum submix. I'm using a dual mono compressor, it seems to me that the best way to preserve the stereo image is to; set both channels exactly the same and key one side on both channels, i.e. left side straight signal and the right side listens to the left signal... I'm wondering how a stereo compressor works, does it sum the sides to mono and react to the overall signal? Or does it only listen to one channel as well? I can't imagine a straight dual mono compressor set the same on both channels alone would keep the same image. Is there a better way (aside from buying a stereo comp...) to do this?