Crystally

I'm recording a classical music concert. I have a Sony Mz-Rh1, and a Ecm-ds70p electret condenser mic. But why does the mic sens have to be set at LOW? Shouldn't the mic sens be at HIGH if classicial music hall is without an amplifier? What settings do you suggest I use to make a good undistorted recording? Or am I gonna need another microphone or something?

I just bought a MZ-RH1 recently, The software took a while to get used to. I'm using an ECM-719 microphone. I'm going to a concert tommorow night. Should I record in PCM, or in Hi-SP? It's in an open air auditorium, so there's going to be some "loss", I understand. Is it worth it to record in PCM which is CD quality? And with SonicStage, what transfer settings should I use? should it be as ATRAC3? or just transfer as is?