Galaxy Nexus LTE battery - It's fine...until I start playing media

Can anyone help me explain this? I've noticed that my battery drain is very slight (about -80maH), but the minute I start playing something - be it a video or audio file - this shoots up. Way up.

I mostly use Doggcatcher for podcasts and Spotify for my music - is there something up with these apps that is causing this?

For instance, right now my phone is at -103maH. This is while doing some light web browsing (with Chrome Beta). Now if I go into Spotify... my phone goes up to -425maH. I've seen it go up to -1100maH, which is something my old phone never used to do (and my old phone was a Thunderbolt - we all know how good the battery is on that phone).

Am I doing something wrong, or is it a bug in the OS?