I have a rather old ALA320 Altec Lansing Amp. It's four channels. Right now I have it split 4 ways. In the back I have two Alpine 6x9's Type R's. In the front I have some small type R's (not important). I have a head unit that pushes out 45 watts so I'm waisting a lot of power here. I'd like to bridge the amp so I have 180 x 2 in the back in stereo. Can any of you help me with how to bridge the amp properly? I'm not an idiot but I have very little car audio experiance. Also it may be important the AMP has a switch that says 2ch, 3ch, 4ch. I don't even want to know what the hell 3ch is..
3ch would be using for example the front left and right outputs to power two speakers and then using the rear left/right channels bridged to power 1 speaker.
To do 180x2 simply select two channel mode and then take the front left/right channels and connect negitive from one and positive from the other channel to the correct terminals posts on the speaker. Do the same for the rear. Now your powering 2 speakers with two bridged channels off a 4ch amp.