I have 2 12 and a jvc 1200 watt amp. When ever I turn off my head unit a loud buming noise comes from my sub. I have a 97 acura cl and have a fatory head unit.

 

turn down the level and gain......my system does that shit if certain settings are too high....

 

it has something to do with the delay turn off. some amps have it some don't. when you turn of your head unit, there's still some signal going to the amp before the amp shuts off. there's no other output for the signal so it sends it out of the speakers ergo the loud booming sound. something to that extent. you can purchase some devices online that are called delay turn off to prevent it. you wire it between the head unit and the amp. some work, some don't. what you can also do is run a switch from the amp to turn of the amp first before the head unit. or get an amp that has this delay turn off feature...i think that's what it's called. you can do a sreach on the web about "amp popping" or something like that. here's one that might get rid of it...

http://www.davidnavone.com/amp.html .again, it might help, it may not.

 

It could be also a shitty ground (amp and HU). And make sure you run the RCA's opposite the Power and Remote.

 

he doesnt have any RCAs when its a stock head unit, he has to use a hi-to-lo converter, it happens to me also, get a face

 

Depending on your setup, you can do a couple of things.

Try delaying the remote turn-on to the amp (so the amp turns off later). You can do this easily w/ a diode and a cap (both available from radio shack or similar store) instead of buying something similar from the link above.

Instead of hooking the remote turn-on wire directly to the amp, hook it into the negative side of the diode (diode will have a stripe on the positive side). Connect the positive lead of the diode to the remote-turn on of the amp. Finally, wire a capacitor (say 470 uF electrolytic) from the remote turnon to the amp ground (make sure you connect the positive side to the remote-turn on and the negative to ground).

This will delay the amp turn-off by a second or two. If you need a longer delay, put more caps on (wire same way). If you get more than ~1000 uF of total capacitance, make sure you get a diode that can handle the peak power during capacitor charging (get a medium/large power diode --if you ask for a rectifier diode you can put as many caps as you want ).

If you have a crossover driving the amp, you might want to delay its turnoff until after the amp is off. You can do this the same way as above, just add more capacitance to the crossover than the amp and it will probably turn off later. Make sure that you use a different diode for each device that you're trying to delay.

-- Nihil