sub hits when cd is played - Audio & Electronics Forum

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sub hits when cd is played
Sunday, August 21, 2011 9:52 PM
Since i did my new install of all new speakers and amp i've noticed a slight ring in my speakers it doesnt get worse with higher rpm's but its a constant high ring,all grounds seem good for the amps and recently i noticed while playing a dvd the sub would start playing slightly, it would follow the sounds of the headunit cd drive almost like it was sending a signal to the sub to play, the sub also slightly hits for a split second when i turn the headlights on... any idea what this can be and how to fix it????

Re: sub hits when cd is played
Monday, August 22, 2011 9:43 AM
How is your wiring run to the back (which sides), where is the hot run through the firewall, where is the ground, and how is the amp fed a signal? What feeds the amp remote wire?



car audio noob since 1984.
Re: sub hits when cd is played
Tuesday, August 23, 2011 1:08 PM
Sounds like a blown head gasket.


(tabs) wrote:
z yaaaa wrote:its not much fun trying to argue with a wall.
oh, trust us, we know

Re: sub hits when cd is played
Wednesday, August 24, 2011 8:47 AM
Ground loop.



Re: sub hits when cd is played
Wednesday, August 24, 2011 2:40 PM
i have my main power wire coming from the battery through the firewall on the driver side and my two rca's running on the passenger side,the amp remote wire is run from the headunit and is also on the passenger side both sub and speaker amps are run by this signal wire, and both are grounded with two different cables that run to the rear strut tower (sanded and under a strong bolt)
if it is a ground loop how should i go about fixing this?? thanks for the replys
Re: sub hits when cd is played
Sunday, August 28, 2011 5:53 PM
Separate wires, but the same bolt, right?
If so, that's good.

What kind of deck?



Re: sub hits when cd is played
Sunday, August 28, 2011 6:47 PM
1.turn the gain down.
2.ground your head unit and your amps at the same spot.
3.isolate power wires from rcas, speaker wires and remote signal wire
Re: sub hits when cd is played
Sunday, August 28, 2011 9:40 PM
Im under the belief that you have a ground problem, and/or you need to run your rca's in a route that isn't near any power wires, back in the day when I was still young I'd run all wires together and ground the subs poorly, and that would give me subs that would play to the tune of the engine lol.
Re: sub hits when cd is played
Wednesday, August 31, 2011 4:11 AM
A ground loop is the most common type of noise. It is a difference of resistance between your source and your amplifier. Easiest way to tell is if you get a hum while the car is running, and it increases in pitch when you rev it.

First things's first. The ground wires to everything. Check and make sure you have a clean solid ground from your battery to the body of the car, as well as a good solid clean ground from your battery to your engine. Almost all cars have rubber motor mounts, hence the two grounding locations. Test the grounds with a multimeter set to ohms. Put the one end of the meter at the one end, then the opposite lead of the meter at the other end of the wire. Which side you put the leads on doesn't matter. Anything less than 4 ohms is generally acceptable, but the lower the better. My grounds all have a .3 ohms or less resistance.

After you check that, we start troubleshooting the inside components. If you have a pioneer deck, they're notorious for blowing the pico fuse. ground the outer RCAs to the body of the radio. This will usually remove all the noise.

Start with each component to troubleshoot if you do indeed have a noisy component. Take a cheap pair of rcas and cut one of the ends off. strip and twist the two wires together. This will make you a muting plug. Fire up your car, turn the radio on, and plug in the muting plug directly into the amp. Check all of the channels of the amp. If there's noise from the speakers, then the problem is with your amplifier. Check the grounds for the amp, and if that doesn't cure it, replace the amplifier.

Next check any signal processors/line drivers/equalizers. Use your muting plug on the input of the device, never the output, unless you want a paperweight. If you do have noise coming from one of these components, take the ground of it and run it to the exact location of the ground for your amplifier. If you have no noise from these, we go on to the next step.

Pull your radio out. If you're using the factory ground, take a run of 12 gauge wire right back to the ground where the amplifer is grounded to. Better yet, if you can, run the wire right into the terminal of the amplifier. Upgrade your power wire as well, and be sure to fuse it.

To test if it's a bad radio or not - try another radio (duh) or use an mp3 player and plug it into either your eq/processor/driver or if those don't exist right into the amp. You can also hook up your head unit to a battery or a jump pack that isn't connected to your existing electrical system. If there's noise, then it's a bad unit. If not, keep reading.

Check and make sure your rcas aren't close to power wires. Check and make sure your speaker wires aren't sitting on long runs of power wire either.

The last thing that it could be is your alternator. Alternators make, by their nature, AC voltage. There's diodes or a rectifier inside of an alternator to change the AC into DC current. If your diodes are going bad, then this will then introduce noise. Get your alternator tested.





Re: sub hits when cd is played
Wednesday, August 31, 2011 6:19 PM
What kind of head unit do you have? Pioneers are notorious for blowing the diodes on the RCA grounds if you plug the RCAs in with the radio on.



Re: sub hits when cd is played
Sunday, September 18, 2011 9:26 AM
sounds like a bad ground issue.

Re: sub hits when cd is played
Sunday, September 18, 2011 10:39 AM
Run the remote wire away from the RCA's. Make sure all your grounds are good. Are you running a pioneer head unit? They are notorious for burning a circuit trace to the ground on the RCA cables, causing your ground for the audio signal to be pulled though the cars electrical system.


- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs
Re: sub hits when cd is played
Monday, February 13, 2012 7:40 PM
hmmm a little late but finally got around to coming back to the site and to answer some questions i have a dual...not the best choice i know but i don't believe its the head unit im only assuming this because i had the head unit before i installed the amplified aftermarket speakers and i had no problems with ground issues but once i installed the amp it all started, i think ill try the steps lanman suggested and see how that works, also if anyone can point me in the right direction with a related problem i stumbled upon when i was working on this issue, after i was digging around in the dash the head unit wouldn't start up and i found that the factory yellow wire powering the head unit no longer had any power and none of the fuses seem to be blown any ideas on that also?
Re: sub hits when cd is played
Tuesday, February 14, 2012 12:53 PM
Wow, 5 months later?



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