I curently have three 10 in mtx blue thunders that came in a box from mtx that a friend had baught brand new, which are I think 8 years old and they are each 12 ohm and there each wired two the back of the box. the amp sees a 4 ohm load.

My question is I want to go down to two subs, then my amp will see a 8 ohm load and my amp will end up puting out alot less power then its suppose to, can i use a 12 ohm resister or higher so the amp will see a 4 ohm or 2 ohm load?

 

if you went down to one sub you will have 6 ohms, not 8. Adding a resistor will not help you get any more power as the resistor will burn off that power in the form of heat. It would be like slappin a super charger on yer stang but leaving the parking brake on....

 

would this be ok. run two of my subs at 6 ohm on a amp thats rated at 400 watts at 4 ohms. I think I read that the sound quality would go up if I did this. not too sure if im right.

 

You can run subs of a higher impedance on the amp. In your case you can run the 6 ohm subs (assuming they are 6ohms each) wired in series to give you a 12 ohm load (assuming you are only running 2). This is fine for your 4 ohm amp. You just wouldn't want to drop below a 4 ohm load because it could cause the amp to burn up.