Engine idle sound and thud/pop when powering off

[KingKole02]

Ok I had my sub running fine.
I uninstalled it to pick some people up the otherday.
When I reinstalled it, I got a rumble sound, like the engine ideling instead of music.

I didn't change anything, so why is it doing this, how can I fix it?

HELP!!
Thanks

More detail:
Had installed wires and set for one night, next mourning installed amp and woofer. Worked fine for a week. Uninstalled to put in luggage. Changed amp location and rewired and now sounds like c***. Has engine idle sound while playing and thud/pop on shut down.
Whats the deal?

Update:
I routed back the remote and RCAs to come straight out of head unit and lay across the seats to hook into amp, No help.
I moved the ground to new locations and some were worst but still not perfect.
I will try to tape/wire loom the wires in the back of the head unit so as nothing is touching the RCAs.
I think if that fails then I will try new RCAs.

[bigdogdad]

You should have left well enough alone. Good luck in finding the cause. My first (and probably only) guess would have been the ground.

[Gear_Head]

King, where did you move your sub to/from. It sounds like either a ground loop issue, or possibly picking up some rfi from re routing the wiring. did you move the sub, or the amp or both? If you moved the amp, try grounding the amp where it was originally grounded. Also look at where you rerouted the wires. The signal lines should be routed away from any +12v lines to avoid any possible interference. When I mounted my amps in the back of the cruiser, I ran the power down the drivers side kick panels and the signal lines down the passengers side kick panels to avoid any kind of interference. If all else fails, there are a few noise filters available to eliminate noise through the power inputs . Here is a link to look at
http://www.partsexpress.com --> do a quick search on noise filters

[KingKole02]

GearHead,

Yes this is what I have the "Alterntor whine" noise.

I had rerouted the RCA and REMOTE through the back of the deck over the seats and not touching anything and still the same noise. Even with all the wires seperated.

I moved the amp from the trunk location to 2-3IN up to the drivers side seat. Had all wires run in same location as origianlly worked proper and hooked it hours later and it didn't work properly. So now Im starting to seperate the wires.

What would cause a thud/pop when turning off the speaker when before it didn't do it?
I specifically bought my amp because of the soft on/off built in. It now seems like I need to install a relay.

Thanks for some info.

[KingKole02]

quote:Originally posted by bigdogdad

You should have left well enough alone. Good luck in finding the cause. My first (and probably only) guess would have been the ground.

I wanted to show it to you when you were at the picnic. Remember how I said I needed to get family at airport. I had to uninstall everything for the luggage to fix.[:I]

[KingKole02]

Gear head
I tried your link and found these marked down by 70%
http://www.partsexpress.com/pe/showd...number=079-044
So I figured I would buy 4. They may be useful somewhere. There not much as far as ampridges but there the same as the rest.

But what would I really need for mine. I mean what amp rating?

Well I also just bought on of these
http://www.crutchfield.com/S-AfmUHC9...=noise+filters

[Gear_Head]

King, is there a remote on wire on the amp? look at the documentation for the amp and see if it is an autosensing amp. Those delay the turn on until after the head unit is initialized. Thus turning the amp on AFTER the head unit has stablized. The delay is not very long, but enough. If it is not autosensing, then it may require a remote on wire that basically performs the same function. On initialization of the head unit, the amp is signaled thru this wire and amp turn on is delayed bypassing the turn on thump. There may be an issue with installing the amp physically closer to the engine compartment than before. You might try moving it back to the trunk, wired like it was before to test that. I know it os a PITA to do that, but that will tell you if that is indeed part of the issue. I have had some amps that are extremely sensitive to the type of Radio Frequency interference that an alternator emits. It could be that the difference in physical space between the amp and the alternator is enough with the amp installad in the trunk area to eliminate picking up the RFI from the alternator.

It could also be that the RFI is fooling the autosensing circuit in the amp (if it is autosensing) into sensing the RFI as audio signal, thus negating the power on delay causing the thump as well as the alternator whine you,re hearing.

You might try this before you attempt to install filters. If the RFI is being sensed by the amps position to the alternator rather than having it introduced into the amp thru the wiring the filter may not help. That is not to say that they cannot help, bit it is best to Identify how the noise is being introduced into the amplifier.

If you want to talk about this, give me a call. Send me an e-mail for me to reply to and I'll send you my phone#. Send the E-Mail to my work address: gillla@techservintl.com

[KingKole02]

quote:Originally posted by Gear_Head

It could be that the difference in physical space between the amp and the alternator is enough with the amp installad in the trunk area to eliminate picking up the RFI from the alternator.

It could also be that the RFI is fooling the autosensing circuit in the amp (if it is autosensing) into sensing the RFI as audio signal, thus negating the power on delay causing the thump as well as the alternator whine you,re hearing.

You might try this before you attempt to install filters. If the RFI is being sensed by the amps position to the alternator rather than having it introduced into the amp thru the wiring the filter may not help. That is not to say that they cannot help, bit it is best to Identify how the noise is being introduced into the amplifier.

If you want to talk about this, give me a call. Send me an e-mail for me to reply to and I'll send you my phone#. Send the E-Mail to my work address: gillla@techservintl.com

Now you starting to confuse me. I know that the position should not effect the amps sound because its in the same location just up on the seat back but still in trunk, like I said about 2 in which is nothing.

I will have to email you and give you a call about the RFI thing. Im not sure what that is.

Im sending an email.
Thanks for some help.

[maelxich]

im currently experiencing the same problem. Ive got an 800W sony Xplod amp, powering 2 600W pioneer subwoofers. the alternator noise came out of NOWHERE one day, and i have no idea how to get rid of it. i was hoping it was a ground problem, but
1) the grounds always worked in its current location (hooked to the little ring behing the back seat near the floor)
2) I've changed it and tested it in different places and it doesnt change anything.

please someone help, i just went and spent money on this new system, and i cant even use it to its full sexy potential

[maelxich]

Alternator Whine in Car Audio

theres a link that im going to test out tomorrow.

Come to think of it, i didnt have my problem with my old amp which was well...old.

its gone on fire before and 2 of 4 channels were blown, so its safe to assume it wasnt putting out full power.

it says alternator whine is from a different of voltage.

so now with the 800W im assuming my ground cant handle it?

im just thinking out loud and hoping someone can help.

i think i just need to change the ground location.