QP5. Speaker Hiss when depressing brakes..!!

MC_Bob

Member
Messages
133
Bit of an odd one!
2008 QP5 Prefacelift.
You can hear a hiss with the volume turned all the way down, but the screen assembly on. The same hiss can be heard when listening at quiet volumes.
Oddly, the hiss gets slightly louder for about 4 seconds when you press the brakes, or do an action like use the indicators!?

I removed the boot lining, and refixed all ground points I could see, also unplugged and replugged the amplifier in the boot. I removed the headunit to see if anyone previously had touched the wiring.

Has anyone ever experienced anything like this?

Its not awful, and I could live with it, im just sure its not normal?
 

Ewan

Member
Messages
6,757
It's an Italian sports car (all be it one with 4 seats). So of course it's going to be upset and hiss at you in disapproval if you touch the brakes.
 

MC_Bob

Member
Messages
133
Im not sure where to start after doing the trunk earths. Including the battery earths. Ill check but pretty sure it does it with engine off too.
 

allandwf

Member
Messages
10,958
Check the earth on the radio unit, (or whatever they are called these days.) It's picking up interference that should be screened or suppressed.
 

outrun

Member
Messages
5,017
It's an Italian sports car (all be it one with 4 seats). So of course it's going to be upset and hiss at you in disapproval if you touch the brakes.

Actually, it doesn't approve of the noise coming from the radio drowning out the sonorous V8. Turn off the radio, problem solved. :)
 

MC_Bob

Member
Messages
133
Thanks for the helpful comments!
I removed dash needed and unplugged the mic, there is a connector 2 inches down. All hisses gone and the annoying random volume increases/decreases are absent.
Awesome!