I've had this EQ for a while now, have had no quality issues with it. The knobs are kind of small, but then again, it's a 1/2 din sized EQ. I've run a few different setups, including Diamond Audio D6 components and subs, Alpine Type R coaxes, Alphasonik Components, an eclipse alum 12" sub, and as many as three seperate amplifiers. This really lets you"dial in" the music to your liking. It gives you WAY more flexiability than the typical 3 band parametric you get with most head units. The power plug is a little small, but manageable. The additional voltage and sub out adjustment makes a big difference for your gains on your amps. It's much easier to balance the levels and get much higher efficiency out of your amplifier(s). For the price, this is a really nice upgrade for any system. Plus the sub out 'kill' button is great if you don't need the bass (grandma, kids, etc...) in the car for the time being.