[Hallucyn8]

It seems that we are pretty much where we started with this thread: in order for ReplayGain tags to have a effect that you can hear you also need to set a peak tag of 1.0. I have no idea if that is reasonable or not.

At the risk of bumping this thread unnecessarily I just wanted to make a further comment based on some more testing that I have been doing. My conclusions are that for the ReplayGain settings to apply correctly the songs either need to be tagged with a peak of 1.0 or have no peak tag at all (as the code will assume a peak of 1.0 if there is no tag for this).

This may have been what you meant anyway but just wanted to clarify as it may help in any future fix.

For reference in order to work around this issue at the moment I have taken a backup of the existing album peak tags on all my tracks by copying the value to an unused tag and then removed the existing album peak tag completely. All playback tests since updating my library now playback, to my ear, correctly and at a consistent volume. Should the issue be fixed I can copy the tags back to their original location to put things back how they were. I did this using some custom actions in MP3Tag from my Windows laptop if anyone is interested.

One additional thing that I think may be worth mentioning, and is something I've picked up on while trying to educate myself more on the science behind ReplayGain, is that if Kodi now has a built in way of stopping clipping (as I think was mentioned elsewhere on the thread) then I think the peak tag is irrelevant as from what I've read it's only use is to alter the gain if applying the ReplayGain settings would cause a track to clip. If Kodi is handling clipping outside of this calculation then presumably it doesn't need to worry about whether the tag is or isn't there or indeed what it's value might be.