After a couple of days of testing I discovered the music player in BB v0.4 (Froyo) practicaly mutes all sound below ~100hz while playing through Bluetooth. The analog out (headphone) sounds great.
I tested Canoygen's latest v6 rc1, and it's player sounded fine. Then I randomly selected the MixZing player for testing on BB v0.4, and it sounded normal as well.
MixZing is fine as a bandage for now, but I would rather use the standard player. Has anybody else seen this, know of a solution?