Subwoofer Pulseating Problems..... | Ford Explorer Forums - Serious Explorations

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Subwoofer Pulseating Problems.....


Well-Known Member
January 14, 2008
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Year, Model & Trim Level
1998 Explorer XLT
ive prity much solved all my sub problems thanks to everyones help but my last problem..

every once in a wile, both my subs start pulseating, and wont stop unless i turn off the head unit/or the car but once its back on it keeps doing it, with the volume all the way down. if i turn off the car for 6+ hours it will stop, but starts agian later

any ideas?... & is tis bad for the speakers? there hitting very hard when doing this

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btw i got Kicker l7 r15's and i tryed lowering the amp level w/ no luck

and thanks for anyones help

you probably have a remote line hooked up which isn't sending an "off" signal to the amp.

the amp will only hit and play if there is a signal coming to it, to turn on and off, that's what remote is for... from what i've learned...

i don't have any formal training or experience, but this is what i did for mine, and i had a similar problem...

you have a few options, try the following, they may not be convenient, but should help.

1. get a small 12v switch, and wire that into the remote wire, so when you turn it on, the amp will go, and when you turn it off, the amp won't hit. in essence, you could lisen to music with or without bass, your choice.
2. wire in a switch and relay into the power line... wire the switch to the relay, to open and close the circuit to the amp.
3. go to an audio shop and have them fix the problem.

what's happening is your amp is getting a "dead signal", and is just pulsing for the hell of it...

now this may or not be right, if it's not i'm sorry, but it's what i think the problem is... good luck with it...

nope, the remote line works, when i turn off the head unit the sub goes off and vice versa. it only happens when the head is on and happens weather vol is low or high, but when the vol is up it still hits but pulseates between the beat


Try a new RCA cable. It sounds like one may be shorted inside the jacket somewhere, which is VERY easy to do. You may also have a small short in the speaker wire which is trying to put the amp into protect mode. What amp/head unit?

If you have not done it, recheck all of your cables. You might have loose ground or a pintched wire some where, maybe where you came through the fire wall. Check the connections on the sub, etc. You know you have a problem but where is the question, so you need to start ruling things out. Until things start getting ruled out we came only guess where the problem is.

yeah.... and as elementary as it sounds, make sure the rca is running separate from the power line... the electromagnetic interference from the power line will jump over the rca line if they're to close... i ran mine on complete opposite sides of the explorer...

what voltage is your headunit putting out? 2.2vlts? 5vlts? maybe there's not enough signal to the back. a booster?

might want to try a little tool you plug into the rca plugs into the back of the head unit, then your rca's into the tool... suppose to cut out any extra noise..

I've had a similar problem in the past and it ended up being a bad RCA output on the amp. Temporarily swap the cables out and see if it fixes the problem. If not, I would bet it's the output on the amp.

yeah, that's the only real thing you can do with subs and amps... switch things out and narrow what it isn't...

I had an amp do that in the past. I think the speaker leads touched while on.

Amp was

its very rare, but there are a select few amps out there (like older mtx mono amps) that have that problem when the gain is too high. we used to call it motorboating. but if turning the gain down does not change anything then thats not the problem.

more then likely it is a bad rca cable or the rca's are pincehd somewhere. it could also be a loose ground connection.

of course the worst case would be that the amp is bad.