weird thump sound from subs

[greg22-us 10+ year member]

Ok I looked around and couldnt find anyone with this particular problem. My system consists of pioneer avh 3100 hu american bass sq900 an American bass 100.1 feeding 2 12" tnt's with a second battery in the trunk. Well I use an usb for my music and lately everytime I switch songs my subs thump quite loudly i also noticed it does it when switching radio stations I checked the grounds and they seem to be tight any help would be greatly appreciated thanks

Click to read more...

 

[Jepalan]

What is the last thing you were doing with your system before this started happening? Had you made any changes? Tweaked gains? Moved some RCAs?

 

[jrdnhsnbrg 10+ year member]

Sounds like an issue with the HU to me... If it only happens when switching songs or radio stations I'd try a different deck and see if it still does it

 

[greg22-us 10+ year member]

Nothing I got up for work and it started thumping as soon as I switched songs so I switched over to the tuner and still did it now i went out at work and used the aux jack to play music from my phone no thump!! Has me totally perplexed i have searched and cant anything with this problem I am worried I will damage the subs

 

[jrdnhsnbrg 10+ year member]

Were you changing songs on the HU when you had it plugged in with the USB?

 

[greg22-us 10+ year member]

Yes i was I switched songs with the hu using usb and the thump I switched songs from my phone using the aux jack NO thump

 

[jrdnhsnbrg 10+ year member]

Yes i was I switched songs with the hu using usb and the thump I switched songs from my phone using the aux jack NO thump

Try a new HU in there and see if it still happens.

 

[greg22-us 10+ year member]

**** I hope that isnt it but I will try that and thanks for the help!!

 

[bbeljefe]

You said you checked grounds but did you check the head unit ground? Most people don't and the head unit ground is the reference ground for the audio signal all the way to final amplification.

When the head unit ground (normally the factory ground) goes bad, the head unit seeks ground through the antenna and some pretty freaky shite can happen. I would run a separate ground from the head unit to a good spot on the body of the vehicle before I went to changing expensive components just to test.

You can even run a temporary ground wire from the head unit to the amplifier ground and see what that does before you go to the trouble of routing wire under the dash.