VZ - Front Left Speaker Problems - Can Anyone Help?

[scoMale]

I've got some really wierd behaviour happening here...

My front left speaker occasionally drops in and out. When its in, it sounds totally fine - but when its out the volume goes real quiet in both the door and tweeter speakers. It does appear to be related to shaking, as going over bumps will ocassionally cause it to cut in and out. I have found turning up the volume enough will usually jump start the speakers back into life when they are out.

I've done some testing on the cabling, and tried unplugging just the tweeter and then unplugging just the door incase one of them was shorting, but they stay quiet throughout this plugging and unplugging.

I have also tried wiring directly from my stereo to the speakers (bypassing the factory run through the car), and it makes no difference. I have even tried feeding the speakers with the signal from the rear left speaker, and it still makes no difference.

Has anyone got any idea what might be going wrong - could both speakers be blown????

[Luke0011]

I have the exact same problem on occasion. My vz is still factory, i find it happens after a long drive like 30 45 mins. The front left will cut out, and i turn it up and then it will swap, the front right will cut out and the left come on. Strange. It only happens like once a month, but i beleieve the problem is in the factory unit.

[holdenboy]

What does your system comprise of? sounds like it isnt standard to me.

[scoMale]

I have changed the head-unit, but everything else is standard - I have noticed that when I disconnect the FL speaker wires at the head-unit end of the run, I hear a crackling noise on the speaker...

I am trying to figure out how the cabling works for these speakers.
On the front left side under the glove-box, it appears as if the speaker cables run back to where it came from - is it possible that they run back to a crossover box somewhere else in the car to split the tweeter and door speakers?

Does the VZ have factory crossovers? If so, where are they hidden?

[scoMale]

I discovered that hidden in my boot was a 4 channel amplifier that was part of a 'sound system upgrade' that (apparently) comes standard in a Calais!!!

This is great, because I can now run RCA connectors straight from my head unit to the amp (rather than inputting the speaker wires as was the case previously) to get a considerable improvement in audio quality.

Doing this fixed the problem with my speaker cutting out, as it was likely a problem with something between the speaker wires and the amp (there must be some kind of attenuator device to lower the speaker levels for the amp between the HU and the amp).

Luke0011 - check in your boot on the LHS beneath the carpet on the side wall - you may have the same set up...

[Luke0011]

The VZ acclaim and vz berlina do not have factory amplifiers. It must be an aftermarket fit. or a pre ordered upgrade. which i doubt

[scoMale]

There is a user guide in with my books etc, that describes it as a Holden Sound System Upgrade. A little research on the web found it for sale on ebay for $795, and they call it a Blaupunkt GTA450 Amp:
BRAND NEW GENUINE BLAUPUNKT SOUND SYSTEM UPGRADE