JBL powered sub issues

[RGKeller]

Hello all. New here and looking for advice on some issues I've been having with my JBL powered sub. I installed it about 2 years ago in my 2017 Ford Escape with the larger screen but non Sony system and it worked fine for several months but here recently it's been acting funny. I used the speaker level inputs to get signal and tapped into the speaker wires behind the factory head unit. Like I said all was good at first but here recently it's been getting quiet at times then will go back to normal operation. Sometimes it will do this back in forth several times during the same song and other times it will be longer periods before switching. I don't think it's ever shutting completely off or going into a protection mode or anything. It just gets quiet at times then all of a sudden gets louder again. I was told in a Ford Escape forum that the factory head units control module is actually sensing there is another speaker present and is cutting the ohms down to 2 to protect itself. Could this really be happening or is something else going on? Anybody else with a Ford run in to this issue? Any ideas or info would be much appreciated. Thanks all.

Click to read more...

 

[Jimi77 Premium Member]

I doubt the stereo is sensing another speaker since the high level inputs on the subwoofer amp should have a very high impedance.

Do you have some sort of noise canceling on the stereo? Does volume drop on other speakers?

 

[RGKeller]

No noise canceling that I know of. It doesn’t seem like any of the other speakers volume drops at all. I’ve tried fading front to back and left to right when it happens to see if there is a change and there isn’t. I tried unplugging the remote gain knob to see if that made any difference and it doesn’t either. All the wires seem to be connected tightly and nothings loose that I can find.

 

[1aespinoza Premium Member]

All the wires seem to be connected tightly and nothings loose that I can find.

Try connecting your phone to the sub via 3.5mm to RCA cable. If you cannot replicate the issue, then the powered sub is ok.

 

[RGKeller]

Okay I'll try that nd see what happens. Thanks all.

 

[RGKeller]

Update.
I couldn't try connecting my phone to the sub because once I disconnect the high level inputs the amp won't turn on. It's using the high level inputs as the remote turn on and I didn't feel like running a separate remote turn on wire just for testing purposes.
I did notice though that when I move the wires I have run for the high level inputs you can hear noises coming from the sub every time I touched or moved the wires. So now I'm wondering if the issues are something to do with the wiring itself. Would getting a LOC and running RCA's for the signal change anything?

 

[audiobaun 5,000+ posts]

Update.
I couldn't try connecting my phone to the sub because once I disconnect the high level inputs the amp won't turn on. It's using the high level inputs as the remote turn on and I didn't feel like running a separate remote turn on wire just for testing purposes.
I did notice though that when I move the wires I have run for the high level inputs you can hear noises coming from the sub every time I touched or moved the wires. So now I'm wondering if the issues are something to do with the wiring itself. Would getting a LOC and running RCA's for the signal change anything?

Sounds to me from this response, that you have some wiring issues that need to be addressed/checked and possibly reconnected properly. Id check the wiring, pulling the HU and check all connections before spending any funds. Could just be loose connections making the proper contact, that will happen over time from road vibrations if not connected properly. Soldering and heatshrink generally stays connected the best from my experiencing. Using Butt connectors work very nicely when used properly and crimped well. You can always run some electrical tape around the outside of RCAs exposed connection once connected to help from a little more noise issues,. Check your wiring first. Make sure all are connected tightly first before spending any funds. Its going to cost you some time Yes, but may save you some funds and fix your issues

 

[1aespinoza Premium Member]

So now I'm wondering if the issues are something to do with the wiring itself

Try wiggling the connector that goes into the amp. I have seen solder joints in the circuitboard develop hairline cracks that cause the issues you mentioned. If this turns out to be the issue, you can just hit the joints with a solder pen to solve it.

 

[RGKeller]

Try wiggling the connector that goes into the amp. I have seen solder joints in the circuitboard develop hairline cracks that cause the issues you mentioned. If this turns out to be the issue, you can just hit the joints with a solder pen to solve it.

To be clear I was touching, moving the wires where I connected them right behind the factory head unit, I wasn't touching them close to the amp. All the connections seemed solid still but every time I moved them you could hear static coming from the sub. Could the wire itself I used be bad or just degraded because they were old speaker wire I had lying around?

 

[1aespinoza Premium Member]

Could the wire itself I used be bad or just degraded because they were old speaker wire I had lying around?

Unlikely. I would recheck those connections if you are getting static.