Up the the sub

[omega88]

So I have an alpine M500 I believe it's called, does anyone know if there's a unit I can plug into it to turn the sub up or down, for more or less boom?

 

[audio1der]

Do you mean the Alpine MRP-500 outboard power amplifier? If so, look on the end which has the (red & white) RCA inputs, and look for a "gain" knob; you'll probably need a tiny screwdriver to adjust it. Turning it counter-clockwise will turn the gain down, turning it clockwise turns the gain up.
If this is not the amp/device you're talking about, get us a pic?

EDIT- just a thought; if you have an MRP500 you probably have an aftermarket sub too. If so, if there any polyfill inside the enclosure? You can get polyfill at any fabric store for under $10; lining the sides on an enclosure with it helps eliminate boominess.

 

[LB3711]

here is the manual for that amp http://vault.alpine-usa.com/products/documents/OM_MRP-M500.PDF Just adjust the gain and bass EQ on the amp and the bass on the radio to adjust the bass that you want.