Cubase 5: mic volume reduces gradually during recording.

I’ve been having a very odd issue lately. When recording some songs with a friend and his guitar, during recording the mic volume gradually reduces. When we start, it’s perfectly normal, but then after about 30 seconds the volume starts to drop until you can barely hear him and I have to open up the gain completely. I can’t find anything about it on the web, does anybody got a clue? Any tip will be very much appreciated.

Hi and welcome,

Make sure, there is no any Compressor or Limiter applied in the signal path. Also make sure, there is no automation.

Most often also the musicians (especially vocalists, speakers) really do so. But not in this extreme way.