I am running one 12" sub off a 175x2 amp. I was wondering if I can bridge the two channels together by running positive from one channel and negative from the other channel to achieve 350x1 at whatever impedence it is rated at?

 

Yeah, you can. Check the manual to find out which pos & neg to use, and what load it'll be stable at when bridged.

 

Depends on the sub and amp.

Any GOOD amp and a 4 ohm sub will be happy.

 

it depends on your amp.. it should be able to be bridged tho..check your manual or look at the amp itself.. sometimes you can see which leads you need to use on the amp when its bridged and when not (it might be labeled like on my amp)