Troubles and more troubles Please Help

[LES2010]

hi, i've got a bit of a dilema, i'm running a Jensen VM9212N head unit, Jensen Power 920 4 channel amp, Jensen 6 1/2" splits in the front, Jensen 6 1/2" in the rear doors and Jensen 6x9's in the rear parcel shelf, as a temp measure I had a clarion 4 channel running as 2 channel powering the 4 front speakers and a pioneer 2 channel powering the rears, all good no problems it was loud as hell, then I got the Power 920 and used it as a 2 channel along with the Pioneer, still all was good, then I decided to use the 920 as a 4 channel on its own, PROBLEMS AAAARGH, first there is the horrid whine from all the speakers when the car is on, this gets higher pitched under acceleration, so I tried my clarion 4 channel, this produces a constant high pitched noise when using all 4 channels, if I run 2 amps as 2 channel each I do not get this problem at all, i've tried these things to remedy the thing but to no avail,

1. checked earth at the amp and the head unit, created a common earth, no joy there
2. rerouted cables so there's no power wires near the rca leads, no joy there
3. ripped it all out and started again with the same results using all combinations of amps, no joy there
4. swapped the rca leads around but no joy there

using one amp as a 4 channel amp, If I pull channel 1 & 2 out of the amp but leave channels 3 & 4 plugged in I get no noise, if I pull 3 & 4 out but leave channels 1 & 2 plugged in the same result, happens with both 4 channel amps

I have a VT that has the same h/unit and leads the only difference is the amps, 2x 2channel Jensen Power 400's never had a problem that setup, am I up sh*t creek trying to use a 4 channel amp or should I stick to two 2channel amps, it does solve the problem if I do that.
I've seen a few cars with the same 4 channel setup from Jensen as mine and they don't have this problem with noise at all

[AmmoJammo]

hi, i've got a bit of a dilema, i'm running a Jensen VM9212N head unit

see, I read that bit, and thought "well there's your first problem"

but it just kept going on!

[acarmody]

My first rule in car audio is don't buy gear from Repco.

Anyway, "I had a clarion 4 channel running as 2 channel powering the 4 front speakers and a pioneer 2 channel powering the rears" , do you mean the 2 front speakers or was there 4?

EDIT: Also how are you splitting the RCAs to make them 4-channel amps. Or are you leaving the RCAs the same as when in bridged mode. Because that wouldn't work at all.

[acarmody]

On second thoughts, just give us the model numbers of all the components and I will make you a wiring diagram to try.

And if you don't have the speakers model numbers than give me the RMS power ratings.

[LES2010]

G'day Acarmody, the h/u is a VM9212n, the front splits are powerplus us652c (6 1/2"), the rear doors have powerplus us652 (6 1/2"), the rear parcel shelf has powerplus us693 (6x9), the amp is a powerplus920, the rca leada are Aerpro, and many thanks.
Les

[LES2010]

see, I read that bit, and thought "well there's your first problem"

Bwahaha!!!!!!

but it just kept going on!

doesn't it always

[acarmody]

What about the Clarion amp, what model is it? Your not going to run 6 speakers with one amp properly.

Well theoretically you could wire it up to drive all 6 but you will be pushing that amp to its breaking point. Leave the Clarion in. I trust Clarion a lot more than Jenson.

[LES2010]

Clarion amp is a APA4204

[acarmody]

Try this. This way your 6x9" act as (kind off) subs, since you already have 4 door speakers.