Wied popping noise

[4jb 10+ year member]

I have a jbl 1200.1 that powers 2 12" subs and when i take off my face on my cd player in makes a loud pop. Like the power is ****** out of everything. It also happens when i turn off the car with the music on. I found that turning the volume all the way down, switching to FM radio, and then taking the face plate off makes the smallest ammount of a pop noise. I was wondering what you all think is wrong with my sh*t and what i should do about it?

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[MikeofTulsa Moderator]

if im not mistaken...its known as turn off noise... or somthing similar to that....basicly the amp still has a little bit of power run to it and when the music quits there is still a little power running to the sub and it makes a loud pop sound...if im wrong please feel free to correct me....im not 100% sure on this....

 

[Jasontb2000 10+ year member]

If it is turn on - off thump, you can wire a relay on your remote wire that will keep your amps charge for a little will longer and should stop that thump!

 

[4jb 10+ year member]

Ok this is much better than what i thought it could be. Is there any dangers with this noise to my speakers or amp? Could you explain how i would hook up the relay off of the REM wire to get rid of this ?

 

[Jasontb2000 10+ year member]

I'm sorry!! I had a brain fart. You can't fix this problem with a relay... BUT you can fix it with a diode and a capacitor, here's how..

Take a diode( a 1N4004) and place it in series with the amps turn on lead.(Striped side connects toward the amp) Then add a capacitor in parallel , the Pos. (+) side of the cap. connects to the striped (amp side) of the diode. the neg.(-) side of the cap. goes to ground. (not the ground of the amp but to the chassis. What this does is when you turn your radio off or power down the system, the cap. will cause the amp to have a delayed turn off. (As the cap. discharges the voltage to the amp turn on lead will drop slowly and not all at once.) You will have to play with it to get the right timed delay by changing capacitors. Usually you can use 220 - 1000uF caps. But besure to use a polarized electrolytic cap. 16V or higher. also the diode will keep the cap. from discharging any voltage in a reverse path to you headunit. But it will also cause a 0.7 voltage drop one your remote. I have never really seen any equipment damaged by a turn off thump, but I can't say that it won't! Good luck.