i finally got my subs hooked up and my monoblock going....so i know most of you have your gains set at a quarter and so thats what i did at FIRST. The dmm gain settings way wasnt working for some reason it kept reading the same numbers with the music going and the music off. Anyways i left the gains at a quarter for now and listened to it and i couldnt even feel the subs at high volume so i turned it up to half just to see the difference and then right as you get to half this HUGE rumbling comes from my subs and its constant even if the music is on pause....can someone pls help me with this.

here was a couple of things i was thinking...
1.preouts on pioneer HU
2.maybe bad ground
3.maybe need loop isolator???

 

i have a amp that dose that too. I think its a bad amp not the hook up. i always leave mine turned down and i dont have any problems then.

 

well see the thing is....i had my other sub amp hooked up right before this one and i had the same problem just not as bad.

 

I would say check all your grounds and ****... mine was fine at lower volume but as soon i cranked it... kinda went funky... but i figured out insted of 12v i was getting like 6-7 because bad ground.... so check it and let us know

 

when mine dose that i put a meter on it and it was reading 5 to 20 volts. my amp that i'm using dosn't do that but when i turn it up it cuts in and out and the speakers that are not hooked up to the amp dont make any noise either

 

i have a dmm.....where should i put it to check the voltage and what setting does it need to be at???

 

get a voltmeter, check your power and ground wire. Look for any wires that are pinched...especially to metal. It sound like you got road noise to me.