Bought new last year for simplicity, plug it in, turn up volume on MP3 player, ride. 
Mustang Sally by the Commitments came on and through the speakers it started distorting the Bass so I stopped and turned down the volume. Still no better so changed the track and again it was crackling and distorting on any track.
This morning tried my system again and no problems, clear music through MP3ear phones firstly then through helmet speakers.
So I was thinking I might have the wrong battery (9V-6LR61 Energizer) or just too much Bass?
Wots going on then?
Dakarnoway

Mustang Sally by the Commitments came on and through the speakers it started distorting the Bass so I stopped and turned down the volume. Still no better so changed the track and again it was crackling and distorting on any track.
This morning tried my system again and no problems, clear music through MP3ear phones firstly then through helmet speakers.
So I was thinking I might have the wrong battery (9V-6LR61 Energizer) or just too much Bass?
Wots going on then?

Dakarnoway
