Podcast Mp3 volume control on android

So I'm travelling tomorrow and decided to grab a few podcasts I've missed over the last few weeks and listen to them as MP3's on my phone (as I'll have no internet access), but the volume seems stuck on full blast no matter what. The GBEast are the same except I can re-export the mp3s and then they're fine, though I can't do this with GB cast. I'm on a Sony Experia, not sure what the dealio is here, but seems like a bug somewhere nonetheless

I've since tried VLC player for android, which works, so that's my solution