Subs cut out?

[FLASH]

I need help!
I am not all that system-savvy and recently...my system stopped working.
To my knowledge...it doesn't make sense. All wires are attached as they were when it was working, all fuses are good, and the amp definitely has power. I did check the big fuse up by the battery and it too is fine. The fuse in the headunit is fine, as are the two in the amp itself.

It was working fine until the other day when I showed it to my buddy and thought "Wow this barely sounds on." Then I went to play with the levels and frequency and stuff on the amp, when I realized the subs were not hitting at all.

I even took the subs out to make sure the wires going to the connectors on the box werent fried....everything looks perfectly normal.

Is it possible that the subs just died for no reason? both at the same time? Could it be the amp is just not giving them any juice, even though it has power? (according to the "power" light on it) I do have a Sony Xplod amp which I have heard horror stories about...

Can anyone help!?

[Sentinel]

I think you should get a DMM (Digital Multi Meter) [You can get a decent autoranging one from Craftsman for about $25] and start tracing where you REALLY have power.
Another thing to do would be to hook up a "known good" speaker to the outputs of the amp and see what happens.
You can also start swapping stuff around and seeing (ie: use a different amp driven by a diffreent channel and drive the subs: see if they are good)