Hi guys

I have a sound prob here which is driving me insane,why would a game sound work on a test rig but not in cabs?
the board in question is a tiger heli board which works fine on my rig but if i connect it up in two other cabs
there is no sound even though there is 12V+ reaching the board in both cases?.
Other game boards and MVS work fine in the cabs as normal and all speakers in the cabs and rig are 8ohm,if the audio amp is not 100% i always expect them to be dead!, is it possible they may become fussy about o/p requirements? x_x