Review on 🔊 CT Sounds Universal Bass Knob - Digital Voltmeter, Blue LED Display, Remote Gain Control, Power Switch: Enhance Amp Performance with Durable ON/OFF Push Functionality by Jason Rawls

I was a bit skeptical before purchasing that the volume or sound quality would be compromised but neither of those fears has materialized, this thing is great. The voltmeter appears to be accurate, but there is a potentiometer in the side hole so you can calibrate it if needed. The handle doesn't play, it has a "dead zone" where it won't rotate the handle it's attached to. Loud music or beats don't exactly turn it off. The power LED is ridiculously bright, and I knew that from the reviews, so I stowed it in a 1-DIN flap pocket that's available in Subaru for Foresters, but adapted to work in my WRX. I love that it says 'on' when it's on and 'off' when it's turned off by either the ignition or a button on the dial. I opened it up and was surprised to see that its chip was running on a high quality circuit board. The wires are tiny and the RCAs aren't the best in the world, but they do what they're supposed to do. All the wires are connected to JST connectors to connect them to the board, so I could probably replace them all if I wanted to. I took a 4 wire connector with matching wire colors, put it on the end, soldered it and wrapped it in shrink wrap. From the side of the car the connector was soldered into the wiring harness and the wires removed were crimped and fitted in the car. I used a short 1.5" RCA to connect to the radio. It turns out to be a very smooth handle that does everything it's supposed to do very well.