I'm using Cubase 7E to record and mix tracks, I am try to upload my tracks to Reverbnation, at the moment this is pretty hit and miss so I'm assuming the mix down settings are not correct, this is what Reverbnation require: MP3 format (192 kbps - 320 kbps bit rate, 44.1 or 48 KHz Sample Rate). how do I do this ? Thanks.