Working Great for 5 years then...

Hi everybody,

Ran into a problem with my sound system in my truck the other day. Currently I have a Pionner AVH-X2500BT, a JL XD500/3 Amp, Kenwood KFC-6984PS speakers, and a JL W1v3 Sub. I installed everything myself about 5 years ago and I have really enjoyed the sound and never had any problems.

Just the other day I noticed two problems that have started to occur. 1st problem is my subwoofer at certain frequency's just sounds terrible. It only makes this sound during certain songs at certain frequency and sounds fine at any other time. The sound it makes sounds like the sub is bouncing a bunch of marbles on a metal surface. Just a really crappy sound.

2nd problem is that when the everything is on and I am not playing any music I get a constant small bass hit from the subwoofer and a quite audio tone from the speakers at the same time. This happens every two seconds or so.

What I have done. I inspected the subwoofer and cant see anything wrong with it. I brought it into my local audio shop and they tested it and said it was fine. However they didn't seem very confident. I made sure all the wires throughout the entire system were secured. The power cable is separated from all the others. I cleaned my grounds. I pulled out the RCA's and the bass and speakers still made the faint noise every 2 seconds.

It has been around -25 degrees fahrenheit here in MN so maybe the cold had something to do with it, even though it has survived every other winter just fine. Not sure if the two problems are directly related to each other or not. I have not changed anything for the last 5 years and it was working great. My components are not too expensive so i'm not hesitant to replace anything, I just don't want to replace the wrong thing if I don't have to.

What advice can you give me? Any ideas on the problem? Any similar problems out there? Any other trouble shooting I can do?

Thank you!

 

Have you had your amps checked out? I know that alot of times after long time exposed to high vibrations some times pieces can vibrate out or fail...

I would say that your wires need to be ground to prevent a low humming noise if it is constant, but you are saying you only hear it for a few seconds then nothing?

Is the noise from the sub perfectly timed with the noise from the speakers? Are you running 1 amp? Have you tried new wires?

Is your sub enclosure sealed? Have you looked at the box to see if it has separated anywhere? Can you feel air coming out of your box around where the boards are nailed/screwed/glued? If so you can try to put a few more screws in it to tighten it all back down again. Drill pilot holes!!!!

That is all i can think of right now. I will add more if i think of anything. Good luck...

 

Thank you so much for the help. Some great ideas and advice.

There is some very faint static but that doesn't bother me. The noise I here goes off every 2 seconds or so and is just a faint thud from the sub and a kinda squeak from the speakers.

It is just a single 3 way amp.

The sub makes the weird noise even without the box but I will definitely take a look at that. That's a good idea.

Maybe it's just a bad amp and possibly sub. Still going to try more trouble shooting.

 

Have you tested the sub's impedance? Did you do a cone push test to see if the coil is doing bad things? With everything off, push in the center of the sub's cone through most of the excursion - taking care to spread the weight around so you don't damage the cone or dustcap. If you hear/feel grinding or scraping or scratching you have a bad coil. Either recone or get a new sub if that's the case. Either way, static, squeaks and thuds don't sound like a normally-functioning low end.

That said, my sub's having some issues with the cold too (below zero), but it just refuses to play until the truck gets warm. Could be the amp or sub - haven't figured it out yet since it hasn't been that cold since I noticed.

 

Did some more trouble shooting. The repeating noise stops only when I disconnect the sub. When the sub is disconnected everything works great just obviously no bass.

Everything I've tried won't get the sub to stop sounding like trash during some songs.

Thinking it's got to be a bad sub.

 

Well I put my sub in a friends jeep and it sounded great. Thinking it must be a bad amp. Must be just the sub channel not working right.