Bridging an amp

Ok, here's the hardware I'm working with:  Panasonic DEH2300 cd player (4 channels, 19 watts per channel RMS), Lanzar Vibe 420 amp (4 channels, about 100watts per channel RMS), and a pair of 12" JBL subs (250watts RMS, 1000 peak).  As it stands, I am using 2 channels of my amp to push the subs, and have 2 unused channels.  What I would like to do is use 2 channels to push each sub.  Now, the problem is that the cd player only has 1 preamp out, and I need 2 preamp signals to use all 4 channels of the amp.  Last time, I used a set of RCA splitters to get all 4 channels, then hooked up the subs and they didn't work.  My question is this, since that didn't work, is it possible to use all 4 channels and how do I do it?  Assuming that can be done, can I use 2 channels per sub?

The easiest way would be like you said and use splitters to allow you to use all four channels of your amp.  Then to wire up your subs, your going to to want to bridge the front channel of your amp to one sub, and bridge the rear channel of your amp to the other sub.  Normally to bridge your amp use L+ to positve and R- to negative.  If your speakers still wont work, let me know and we'll help you troubleshoot.