Spotify is a pretty cool music service, and I really enjoy Pulse Audio, especially when combined with tools like pasystray and pavucontrol. Together they have a bit of an annoying "feature" though.
Spotify is smart enough to link its internal volume meter with Pulse's stream volume for Spotify. However, for some reason, Spotify also links the stream's volume to the master volume for the sound device Spotify is on. Blech! That means that when you grab the volume slider in Spotify, everything on the system gets louder.
This is, I am told, a "feature" of Pulse Audio called "flat volumes", and it is supposed to do better things. In practice though, I find it doesn't work and I'd rather just control volume myself. The fix for this, luckily, is simple.
To turn this off, in Arch Linux at least, is pretty simple. In
/etc/pulseaudio/daemon.conf there is line like
; flat-volums = yes
; is a comment marker in this file. Uncomment that line and change the
no. Now there is no silly linking of volume meters, and I can
control volumes independently.
This has been bugging me for a while, but not enough to do anything. The straw that broke the camels back is my new USB soudn card. For reasons I don't understand, the internal sound card on my Thinkpad dock doesn't work in Linux. This is pretty easy to work around. Get a USB sound card, plug that into the dock, and plug my headphones into that.
This works nicely, except the particular USB sound card I got is apparently a bit wonky. If I grab the volume meter in Pulse Audio and lower it below about 36%, the sound cuts off. Apparently that is as quiet as it will go.
Unfortunatly, having Spotify and the sound card both set to 36% volume is too
loud. The solution is to slide Spotify down to around 20%, which sounds good.
Except sliding Spotify down with
flat-volume = yes also lowers the sound
card's master volume, making it cut to mute.
The fix above lets me set Spotify's volume independently, so now I can get a comfortable listening volume on my headphones through my dock. Yay!