Review on PAC LC-1 Remote Amplifier Level Controller,Black,Small: Advanced Audio Control at Your Fingertips by Brian Wolf

If you're dumb like me, try to save money and use this knob to control the high power output (speaker output from the canbus amp). TBT you will need a high output to RCA converter if your amp doesn't have one built in. This control only boosts the signal present, it has NO ability to reduce it beyond the initial head unit output. (or in my case a canbus amp). I still give it a great rating as it does a great job of what it advertised. I will buy it for all future cars as the PAC brand is way better than generic for the same price!