The four post are for the voice coils your sub seems to be a dvc, althought i''ve never seen those before. By the number on the magnet (RA-12d4), usally means the sub is a daul 4ohm voice coil. Now according to Ohms Law, wiring POS + POS, an NEG + NEG, on 4 ohm load drops the load to a 2 ohm load. So once you bridge your amp it drops the load again so your amps reading a 1 ohm load. An they're are only a few hcca amps that can play at a 1 ohm. I have'nt seen Lanzar amps ever handle a 1ohm load. So to fix your problem try wiring your speaker in series (POS + NEG POS + NEG). this should bring the load fom the speaker to 4 ohms, an the amp'll read 2 ohms. So you should'nt have the problem with the clipping. I hope that helps you out, sorry i tend to run my mouth alot.
