I just put in a Brand new alpine m-500 mono amp, with 4g wire good ground 50 amp fuse it's hooked to NEW 10" kicker comp VR sub in a down firing box. I also have a Alpine head unit. The problem is when I tun the volume up past 19 the sub turns off and then I have to turn the deck off then back on. the amp light is still on ( solid blue) but the sub is off, If I turn the gain way down and the bass setting on the amp way down it will stay on. It's set at 2 OHMs
is the sub a duel 2 ohm or duel 4 ohm? to get a 2 ohm load you need the duel 4 ohm coil not the duel 2 ohm coil. it sounds like you may have the duel 2 ohm causing the amp to go to into shutdown or protection.
I'd just make sure it's wired in series (if in fact it is a dual 2ohm sub). That amp will put out 300RMS x1 @4ohm and 500RMS x1 @ 2ohm. The sub is 300 RMS so it should work just right..
Also, make sure you're not running too much level adjustment or bass boost on the head unit.. Ideally, you should set the head unit up with the sub unkoohed to make it sound good with the speakers and then with those settings setup the gains for the sub using a multimeter..
so I should keep the sub??, I rewired it to series, it sounds good, What should I put all the settings to? I'm new to all this crap lol, it say's its 50-400 rms 800 peak power, so wouldn't i want to get the 4 ohm sub and use more of the amp?
With the M500 amp, you want a 2ohm or 4ohm load...you can get away with a 4ohm load (your current setup), but that amp only produces a max of 300w at 4ohms whereas a 2ohm load will get you the full 500w. I've used that amp and it's a great amp for the price.
If I were you, I'd take your sub back and exchange it for a dual 4ohm sub.
Then wire it like this:
"We don't build great brakes because we think you don't know how to drive, we build them for the guy on the road in front of you that doesn't." - Black Magic Brakes
Well I got my new Dual 4 ohm sub, everything is working great now I want to thank everyone who helped on here. This things sounds awesome!!!!! Love the polk DB speakers and the kicker sub really put's out the bass, The box was easy to make and I still have trunk room