Double Bridging?

[jhubbz]

Ok, I just bought a sub, box and amp off this kid from CL

Here are the specs:

Power Acoustik PS4-800 4-channel
4 ohms: 85 watts x 4 chan.
2 ohms: 105 watts x 4 chan.
Bridged, 4 ohms: 210 watts x 2 chan.

Now I'm assuming the next bridged rating would be something like 260w x 2chan @ 2ohm..... Would this be right??

Also it is running to ONE Alpine SWR-1243d 600wrms, of which has 4ohm DVC.

Now, here is the big question, is it possible (or safe for that matter) to double bridge this thing??? The bridge is currently running off channel 3&4, but if I run bridged 1&2 AND bridged 3&4 and run them both together to the sub and wire that to either 4ohms, would this work? I've never heard of double bridging, but seems like it might be possible. I'm thinking it would be putting out around 500wrms x 1chan @ 4ohms.