Help. Subs pulsing rapidly at high volumes but no sound

[SuperDuty350]

Hey all,

New to all this stuff and could use some help.

So I installed a small system in my truck. It's a kicker Comp r 12. I originally had it hooked to a cheap Boss riot amp. Then I got a kicker cx600 amp which I have since given my brother and now have installed a kicker cxa600. When I had the two previous amps, I don't think I was experiencing any issues. I was running a factory head unit, with a cheap line out converter. I purchased the kicker rca to speaker wire cables and installed them for the amp I have in place now.

Problem is, my sub doesn't seem to want to work when I raise the volume to to about 3/4 on the head unit. They stop hitting, and I notice the cone moving back and forth rapidly. I also have noticed a hum coming from the sub when the volume is completely off.

I appreciate any help you guys can offer, as I really have no idea what I'm doing. Just disappointed it was working before and now is acting up.

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[Papermaker85 5,000+ posts]

check our grounds. sounds like a bad ground..

 

[SuperDuty350]

I did that. Put a voltmeter to it.

I'm going to tell on myself here, and you guys can laugh me out of the place, but I would rather look like a fool than have a sub not working.....

The line out converter I installed for the previous amps needed to be grounded, so I ran that wire to the same ground bolt as the amp ground wire. When I took the LOC out, and went with the cables, I simply clipped that wire off as close to the bolt as I could instead of taking it out completley. It was hanging out by maybe 1/2 but still insulated...could that cause a ground loop?

Also, when I did the kicker rca to speaker, I wired them all up with butt connectors, the. Taped them all together into the same electrical tape bundle so they would look nice. I suppose I could have taped each butt connector individually, and then bundled them all together. Could that cause a problem? Like speaker signals leaking into each other or something? Just trying to cover my bases on the things that have changed since previous amps.

Thanks

 

[Boomin_tahoe 5,000+ posts]

Use diff grounds. Not the same one. And yes will cause ground loop.

 

[SuperDuty350]

Use diff grounds. Not the same one. And yes will cause ground loop.

That LOC has been removed altogether, and I got the little piece of wire out. Currently only one ground wire coming from the amp

 

[SuperDuty350]

check our grounds. sounds like a bad ground..

I used an Ohm meter and it seemed to stay right at .2

 

[SuperDuty350]

Also, i don't know if this is related or not......I had to jump start my truck. When I took the jumper cables off the other car, Once mine was started, there seemed to be a magnetic pull to the other cars battery I have never experienced when jump starting anything. ????

 

[Boomin_tahoe 5,000+ posts]

Magnetic pull?

 

[Papermaker85 5,000+ posts]

Copper is non magnetic so is aluminum unless you have some really ****** steel jaws on your jumper cables no magnetism was involved.

I'M thinking you have some grounding issues and the pull you felt was the current being drawn through the ground of the jumper cables.

the ohm meter between the amp and te steel where you grounded is telling you simple the resistance between the steel and the amp AKA the wires resistance.

Id try to re-gound the battery and the amp.

 

[BOOMINGRANDPA 5,000+ posts]

Also, i don't know if this is related or not......I had to jump start my truck. When I took the jumper cables off the other car, Once mine was started, there seemed to be a magnetic pull to the other cars battery I have never experienced when jump starting anything. ????

I always pull in line amp fuse before jump starting or doing anything to battery.. but don't know about it effecting hu..

 

[SuperDuty350]

Copper is non magnetic so is aluminum unless you have some really ****** steel jaws on your jumper cables no magnetism was involved.I'M thinking you have some grounding issues and the pull you felt was the current being drawn through the ground of the jumper cables.

the ohm meter between the amp and te steel where you grounded is telling you simple the resistance between the steel and the amp AKA the wires resistance.

Id try to re-gound the battery and the amp.

Yeah. I could feel the jumper cable being pulled back to the other cars terminal post. I'll try re grounding. Could the ground be what is causing the subs not to function well at higher volume? I know it can be responsible for the hum when the head unit is off.

Also, do you think I should take apart the speaker to rca cable bundle I made and tape them all separately?

 

[SuperDuty350]

Is there a better way to check the ground wire instead of ohms between the amp negative and the grounding bolt?

 

[Papermaker85 5,000+ posts]

Yeah. I could feel the jumper cable being pulled back to the other cars terminal post. I'll try re grounding. Could the ground be what is causing the subs not to function well at higher volume? I know it can be responsible for the hum when the head unit is off.
Also, do you think I should take apart the speaker to rca cable bundle I made and tape them all separately?

yea. i htink you are having a grounding issue wt the amps or it could be hte head unit as well..

 

[Boomin_tahoe 5,000+ posts]

OP, your asking the same questions over and over again.

Just take our suggestions and see if that works.

 

[Papermaker85 5,000+ posts]

Is there a better way to check the ground wire instead of ohms between the amp negative and the grounding bolt?

the battery terminal and the amps ground terminal. get you a piece of number 12 wire. ohm it out then connect it to the battery and test the wire you ran to the amps - terminal. take the wire off the battery and connect it to the location of the batterys ground to the chassis. there should be no difference and it should be less than .2-.3 ohm