NVX XVRC2 Universal Bass Knob Level Controller with Built-in Digital Voltmeter, Blue LED Display, Remote Gain Control and Amplifier On/Off Switch

Cool bit of tech to upgrade your amp and speakers. You can completely turn your amp off if you want and adjust bass level at a turn of the knob. Cool extra feature to see your volt level on your battery or at least the charge to it from your alt. I love it. Easy level control at a cheap price. Bright display that's easy to read in daylight.

Cons: as other reviews have stated the wires for positive and negative remote in remote out are extremely small. It is a little bit of a challenge getting it connected other than that. Pros. Besides the small gauge wire it’s fairly simple to install and it works great. My favorite part is I can remotely turn off my amp and my subwoofer when I don’t need them voltage meter works well. The only slight thing I would say about it is at night it is very bright but a small piece of tint over the screen will fix that.

Didn't end up using it want to keep my MKX stock and stealth but this thing is pretty awesome just didn't want some thing with bright lights on it ruining how my classy ride looks not a beat up Tahoe doing 160 db in the lanes

To get voltmeter powered up, I had to connect both yellow and red wires to positive 12V. Level controls works, even if unit not powered on. As shown in video, adjustment screw on back fines tunes voltage display. I turned it all the way clockwise, and then it was only .1 volts off from my direct battery voltage. Seems to work well enough with my subwoofer. I did not connect it to turn my amp on or off.

Excelente

NVX is a great new addition to the car audio world. 21 years into the hobby and I am very picky as well as loyal to my brands. The knob is Super sleek looking compared to similar knobs. The fact you can turn the amp off is awesome! Seems very well made, easy to use, nice and bright, RCA truthfully is the way to go as far as being able to listen to your bass at more than 3 different volumes.

For those complaining about voltage being off, there is a screw on the back to set it correctly. Idk why but my unit controls multiple amps when there is a rca splitter upstream. I thought it was only supposed to affect those down? Guess I need a new head mother multiple outputs

Easy installation

This product failed before even using it. Tested on multiple instances, and did not work at all. Support was amazing though and instantly refunded it.