I am firm believer that there is a correct volume level for each recording. This is not my original idea but makes a lot of sense.
It is a fact that our brains compensate for volume levels. Google Fletcher-Munson for verification. At lower levels the brain concentrates on the midrange and lows and highs have to be boosted to sound balanced.
So the correct volume level depends on what level the guy was listening at when he mixed the recording, assuming that he used EQ, which most recordings do. If he mixed at a low volume he boosted the extremes so if you crank it up it will have too much bass and treble. If he mixed at high volume and you listen at a low volume it will sound thin.
Add this to the fact that the average volume level from CD to CD varies widely (as Bob pointed out) means you need to adjust the volume for each CD to make it ideal.
It is a fact that our brains compensate for volume levels. Google Fletcher-Munson for verification. At lower levels the brain concentrates on the midrange and lows and highs have to be boosted to sound balanced.
So the correct volume level depends on what level the guy was listening at when he mixed the recording, assuming that he used EQ, which most recordings do. If he mixed at a low volume he boosted the extremes so if you crank it up it will have too much bass and treble. If he mixed at high volume and you listen at a low volume it will sound thin.
Add this to the fact that the average volume level from CD to CD varies widely (as Bob pointed out) means you need to adjust the volume for each CD to make it ideal.