Sub pulsing when no volume is on?...

[Kaltenberg 10+ year member]

Me and my friend just installed a system in his integra and after some troubleshooting we got it all hooked up but the sub is like pulsing kinda like a heart beat just slow thump....thump...i dont really know how to explain it but the volume on his deck is at zero, all of his settings should be fine...ground should be good, all wiring is correct...what could the problem be??

Thanks, ill check in after work tomorrow.

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[PaulThompson229 10+ year member]

Very strange...

Probably an issue with the amps internals, do you have another amp you could throw in and see if it causes this as well?

 

[Kaltenberg 10+ year member]

Yeah i have two of my own we could try. He had this memphis power reference amp and memphis subs in his civic last year, sold the civ bought this integ and just decided to wire it up. They worked fine when he look them out of his civic. Idk, i was really confused.

 

[thegreatestpenn 5,000+ posts]

bad ground, I'm like 90% sure of it. test with multimeter to confirm

 

[RidnClean 5,000+ posts]

bad ground, I'm like 90% sure of it. test with multimeter to confirm

x2

 

[MakeshiftAudio 10+ year member]

!!!

It's your amp going into protect via DC biasing. What that means is that you're giving your sub a full DC rail as fast as the SMPS can create it, but the protection circuitry detects that there is a DC signal on the output, and it resets. Do not turn it on too much, a fet is bad on one rail or another, and it will eventually cook your sub.

Simple question: Is it going in and out of protect? Protect light at all?

 

[Jeepjones85 10+ year member]

My buddy's sub did that one time, And it turned out to be the amp. I think this amp was from walmart so he just took it back and got a new one and that fixed the problem

 

[MakeshiftAudio 10+ year member]

Any update?

 

[bmoney9 10+ year member]

mine was a grounding issue..i had to sand a better connection

 

[Sarthos 10+ year member]

Good chance it's the ground, but it could also be the amp. Could be a badly grounded head unit. Less likely, but it could be the RCA wire or if you have a remote bass knob that can also cause it. Mine on a song with 0 bass, turning the knob to full will make it sorta pulse. Can't hear it unless your ear is about an inch away though.