I have a Nakamichi PA1004 4 channel car amp. I have brought it out from the attic, I have no owners manual, (bought it used). I bought a new infinity 475 watt amp and am not all that happy with the sound. I want to hook the nakamichi back up and I cannot figure out how to configure the front and back channels to play in full range mode. I ether get high pass or low pass option on each channel. There is a switch on the amp I am not sure what its true function is? It is marked "Line Selector", and underneath it the options are Lo Pass, Off, CH 1+2. Does any one know how I can set this amp to play all channels in full range mode? Or where I can get a manual for the unit? I would appreciate any help. I hooked up this unit and I like the type of smooth, airy, powerful sound over my infinity amp.But thats just my opinion of coarse. I just cant get the channels set up right yet.