Ok, i have a 12' subwoofer and a Visonik 600 watt amplifier. I have a 4guage power cord. My battery is fine. My altenator is fine. Lights do not dim when amp is on with music playing. Amplifier is set to 18+db bass boost and it is very quiet bass. I have had this system hooked up in my old ranger and it was knocking hard. Now the speaker barely vibrates. The taurus i have the system hooked into now does not have RCA outputs in the back of the radio so i bought a sochoshe output converter so i can have the RCA's for the amp. I hooked the rear car speaker wires into the converter box. (note factory rear speakers still connected) and then hooked up the RCA's. The level on the output converter box is set to max on each channel i have plugged in. The amp is set to maxx Bass. I have the speaker hooked up so that i get the bridged 600 watts to the one speaker. The system is now very quiet. Is this because the output converter box? Please Help if you know anything. Thanks, Derik