Hi ​@Lisa363 

Welcome to the Sonos Community!

Sorry to hear of this issue you are having with varying volume levels across different songs.

There is one very good reason why we do not perform volume levelling - if access to the entire song’s data is not available prior to playback, any attempt to adjust to the song automatically will just sound awful, and this goes against our entire ethos. The correct way to normalise volumes is to scan the entire track and find the loudest peak, then set the gain to adjust that peak to 0 Decibels. Without access to the whole track, this cannot be done.

Another method is for the service (who do have access to the entire track) to either re-encode the track in the manner above and save the change, or, more commonly, to provide that gain adjustment to the player - Sonos speakers will apply this gain adjustment, but can only do so if supplied with the information in the first place - unfortunately, this is not done by many services.

The issue came about some decades ago when someone figured their music would stand out more on the radio if it were louder than everyone else’s - this created a “loudness war”, with the end result being that music recorded before some time in the 90s is recorded “properly” with peaks set to 0dB, and music recorded after this tends to be considerably louder due to increased compression (not to be confused with data compression, which is different).

Ultimately, not much can be done, other than not mixing pre-90s music with post-90s music in a single session.

I hope this helps.