Few issues after headunit + amp install in VS

[nathanVY]

Hey everyone, so I put the new stereo in my VS yesterday. All went well,

Running 6.5" splits all round off an alpine 4ch amp and a new clarion head unit.
We used 4 gauge cables for the amp power, my only queries I have are this:

- alternator makes a high pitched tone when ignition switched to ACC (i'm unsure if it did this previously, it does not appear to be audio related)
- somehow I have a small noise coming from somewhere that fluctuates with engine rpms - i don't think it's coming out of the speakers because it doesn't change with volume and you can still hear it when the volume is at 0.

2x RCAs, Amp Remote and Front left speaker wires were run down the passenger side underneath the trims on the floor.

Power cable was run on the right hand side through the clutch gromet, and underneath the floor trims again.

Right hand speaker cable is run on the drivers side in the roof underneath the seals, roof lining etc.

just to be clear both front speakers are amped so the wires run back to the boot. any ideas/comments/thoughts would be appreciated.

cheers

[nathanVY]

Also the headunit is brand new Clarion CZ209a, could it be a problem with how I wired the head unit it? or more likely to be an amp/earth grounding issue?

I didn't have this problem in my VR but we ran the amp power cable through the gromet on the passenger side, and had to butcher the hell out of it - so in favour of not destroying the gromets we ran it through the drivers side this time.

[VQXTC]

Hey there Nathan, just a quick question. Where abouts did you earth the Amplifier?

Cheers

Simon

[nathanVY]

Hey Simon, earthed the amp underneath the bolt where the centre seat goes in.
Come to think of it I didnt to a great job of removing the paint before I put the earth in, I just used a drill with a wire brush on the end but, not for long enough though.

do you think this could be the problem? the only other thing i've done differently is I soldered the headunit wiring instead of using joiners.

or maybe it's the front right speaker wiring being too close to the power cable? I wouldn't think it would be a problem though as theyre both heavily shielded wiring.

[nathanVY]

Just remembered something else worth mentioning - both the amp power and earths run into distribution blocks and then run 8 gauge to the amp. I am planning on running a second amp very soon when I get my sub.

[rumbldore]

normally when u hear motor sounds cumming form ya sound system it is ya alternator is going well that's what Ive heard but i could be wrong

[R8walkinshaw]

I'v never run front speakers off amp before, but I did have the problem once that your describing where you get a tone coming through the speakers directly relevant to the revs. My problem was due to running all the wiring down one side of the car (RCA, Power, System Remote). I Separated these cables and made them run on either side of the car, this solved the problem for me. I would say make the front left wire run like your front right (but on the left obviously).
Hopefully this sorts out ya problem.

[nathanVY]

I recently fixed this problem in a mates car, but it was 50x times worse you couldn't listen to music it was so loud.
His rcas were entangled with the power cable, I changed the wiring to the same setup I have now and the noise went away - from what I could tell. The noise I have now is really faint and you can only hear it in between song changes if everythings quiet lol - and his exhaust is loud so its possible that I missed it in his car and am noticing it in mine.

So do you think run the front right speaker cables down the left side? Or should I redo my earths first.
Could it have anything to do with the headunits earth? I just used the factory earth cable, should I be making my own earth to the chassis for it?

[nathanVY]

bump, any ideas?

edit: found this link very useful http://www.termpro.com/articles/noise.html

[itchy123]

i had this happen when i used a cheap a$$ audioline amp for a few weeks ( waiting for my new jl audio channel )
sounded like what i would imagine one of those cheap a$$ electric ebay super chargers would be like lol
i would say maybe try a different amp as ive found the cheapos dont filter out interference to well , but u got an alpine :S
(never heard of running speaker wire in the roof before,seems a bit overkill )
but yea just redo ur ground for the amp and see if that makes a diffrence
were the rca leads u used half decent ones ?

[nathanVY]

lol.

the roof seemed like the logical place so I didnt run it next to the power lead?
I used a cadence 1500 watt wiring kit which was rubbish!! never buying another wiring kit again they always let me down.
Didn't have enough speaker wire in it had to go and buy more. But the power leads, fuse, etc werent bad.

I re-did the earth last night and it was pretty dodgy the first time round lol. Soldered the plug on and gave the paint a good sand. Still have alternator whine though :S only in the front speakers from what I can tell.

[VesperZ]

Do what I did, just have to troubleshoot your problem. Try unplugging the RCA from your amp(s) and determine whether you still have the whining sound. If you don't, then you know it will be related to the signal passing through your RCA's. As painful as it may sound, take your RCA's out and run them directly from the head unit to your amp(s). It would be easier if you had a spare RCA because then you wouldn't have to pull the other one out. It could just be the positioning of your RCA cable, or even worse a faulty RCA cable. I determined mine was faulty by doing these tests and took it back and got a new one.

[nathanVY]

Had a go fixing it tonight, it only does it because the amp gain was set to max on both channels. the amp must be old.
turn it back down and up a bit on the head unit and problem solved.

also mounted the amp

[nathanVY]

Ok been playing around a bit, no noise in when the gain is set to 0/nom but it sounds heaps better with the gain up even 0.5 or 1.0 the head unit doesn't have to be cranked to 33 to get half loud music.

But the noise comes back when the gain rises, any ideas? Would a noise filter solve the problem since its not much noise?

[VQXTC]

Hi there Nathan, As a general rule of thumb drop the gain on the amp completely down to zero. Now go to the headunit and turn it up approximately 3/4 of the way (make sure there is no distortion at all) ... Now while the stereo is running go back to your amp and adjust the gains one at a time... (depending on how many channels you are using). Once you turn it up and it starts to break into distortion then back it off just a bit until the distortion has gone and thats the optimum setting for your amplifer. Once you get in the car and shut all the doors and wind up the windows, you may find you need to tweak it a little bit more or less on the gain controls. Once there set dont touch them. To see if your at the optimum or not get an original CD preferably a live recording and put that on. Then listen and see if there is any distortion......

If you need anymore help or advice just 'sing' out..... lol

Cheers

Simon

[nathanVY]

Hey Simon, thanks for the advice.

That's what I've been doing, theres not distortion through the speakers at all.
the alternator noise can only be heard when the volume is at zero and everythings quiet haha
being picky I know, I think it's only coming out the tweeters too.

0 gain = volume 33 on headunit and its barely loud enough.
0.5 gain = not too bad, still noise though but I don't notice it as much as with max gain.

please note the music sounds fine, its only this sound thats at a constant level and does not change with volume.
it's just there and you can hear it when songs change or in some of the really quieter songs.

I'm thinking it must be the amp and the only thing I can do to get rid of it/make it a bit better is put a noise filter or maybe a capacitor in?

One more thing i'm not sure about, on the amp we have some switches:

input channel
1 / ST / 1+2

input channel
2 / ST / 3+4

whats the best way to have this setup?