Quoted from adamross:
I just installed Pinball Pro speaker upgrade and it sounds like sh*t. Sounds garbled, with little to no bass coming out of the sub. Had problems with the original speakers when I first got this machine home but thought the upgrade would solve problems. Could it possibly be a damaged audio board?
Thanks in advance for any help.
There could be something wrong with the amps. Note there are two channels on a ToM. Make sure they are connected properly, J1 should be connected to the cabinet, and J2 to the backbox speakers. J1 is sometimes called J504, J2 is sometimes called J505. Also, I would not recommend a crossover for the cabinet speaker if the Pinball Pro comes with one, it isn't necessary. If there is one, bypass it.
If it is all wired properly, I'd start by removing the connector at J1 and seeing if your backbox speakers sound ok, then vice versa.
Anyway, if none of this helps, I'd look to the sound board for failed components.