Sonos do not apply any volume normalisation to files from any music source and perhaps rightly so in some peoples view.

However, Sonos apparently can and do alter the playback levels using the ITUNNORM or REPLAYGAIN_TRACKGAIN tags in the embedded metadata for a track.

When it comes to general streaming music services though - and this includes things like Spotify - it really depends on whether those mentioned tags are passed by the service to Sonos players, or not.

I understand that you can point Sonos to a local Music Library on a NAS or PC etc. and if the tags are present, or you insert them yourself with a Tag editor, like MP3Tag for example, then Sonos will apply the normalisation. 

I hope that helps.

Ken

Many thanks for your reply. So it looks as if there is nothing I can do re Spotify sourced music unless they introduce a normalisation facility on their service. 

Victor

I don’t personally use Spotify, but yes I suspect that’s the case. Maybe chat to their Support Staff and see what they come back with.

I don’t use any normalisation myself and just go with how the Artist & Sound Engineer intended me to hear their work, but I know that some folk prefer to have this setting.

I would think it’s Sonos position that it’s not their source-data, so they just play it as sent/received by the MSP and so don’t interfere with it too much. Although we can go onto adjust EQ settings and even that (Treble/Bass etc.) area is fairly limited on Sonos. I guess Sonos want the audio to sound as the Artist & Sound Engineer and MSP intended too… er… perhaps?

Thanks again, I totally agree. However, when a particular track has a very low volume compared to others, I don't actually believe that is how the Artist & Sound Engineer intended me to hear their work. Surely it’s more to do with random attenuation somewhere in the system?

Possibly, sure. I’ve had many classical music tracks that tend to use a wider variation in sound volumes. When I went back to my vinyl copies, I found it much the same. But as said before, Sonos doesn’t mess with the volumes that are sent, no compression thereof, nor expansion. They play what they’re handed by the data stream.