Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Finally

I found a good in-line gain control that I can use with any amplifier. I'm sick of proprietary controls that only work with one type of amp. This just goes in-line, and allows me to conrol the amount of bass in my subwoofers for different types of music. I can adjust it on the fly, depending on my mood. Works well, since I have a stock deck to keep the finished look of the dash.