Stringreen, That's an excellent point and one that supports what a good friend involved with the Vienna Opera told me: He said "there is no absolute sound" precisely because of your observation. And then there is position in the audience, humidity, is the hall crowded etc. It never sounds the same. All we can hope for is get closer and closer to what is on the recording. Even that seems fruitless on some level.
However, to Raul's point, there is an argument for trying to maintain a standard in the playback equipment in order to decrease the variables which take us away from what is encoded in the recording.
However, to Raul's point, there is an argument for trying to maintain a standard in the playback equipment in order to decrease the variables which take us away from what is encoded in the recording.