I have the JBL 600.1 mono subwoofer amp that has a dial on the side of it that you select you pre-out voltage. The deck I run is a Clarion DXZ715 that has a 4 volt pre-out, but when I turn the dial on the amp to 4 volts, there is no sound what so ever, but as I turn the voltage dial on the amp away from 4 volts the bass gets louder and louder. Anyone else have that problem or am I doing something wrong or is the amp defective?

 

you dont want to turn it all the way down. an amp is not supposed to get louder if you have more powerful outs (like 4 volts). you have the higher settings for using recievers that have weaker preouts. another thing to note is that the 4 volts is usually the max out. although you are supposed to match the amp and HU, it does not mean it has to be a 1:1 ratio. some people will turn the amp up higher to get more bass. a good test cd will give instructions how to do this. another method i had found was in a car audio magazine using a cheap radio shack amplified speakers. however, since i don't have the article here and i just woke up from a nap (sorry if i dont make sense at times), i cant go into the details. do a search around the boards at www.carsound.com and you should be able to find the details.