I'm going to be very uncool here and say I don't understand all the Bose hate.

I've had several Bose products over the years, always sounded great and worked well. I currently have a 2.1 Acoustimass system for my office setup connected to my Mac Pro.

The acoustimass system is largely designed for someone with no clue to install themselves. So a little knowledge can be a dangerous thing

The super thin speaker cables have always bothered my though. I swapped them out once, couldn't tell at all.

Sounds to me like someone has tried and failed to be cleaver with this system. I would tone back from the speaker end, disconnect everything at the receiver end and see if the tone is coming up on something un expected, sounds like a wiring fault to me.

Edit - You should also be able to use the Tone and probe to see if one of the pair has been cut along the route, it was very very handy when I used to work in Telecoms!

Cheers

Cris