ICE install problem - getting interference

[Patryn999]

One other thing to check (I did read the huge-ass amount of text, but I thought I'd say it directly) is to make sure that the RCA surround on the plugs is actually contacting on both the amp and head-unit side. I had a good one once where the RCA plug outer wasn't actually contacting the socket; this meant that the small-signal ground was referenced through the chassis instead, which introduced alternator noise. Bit of a chomp down on connector to make it more oval (and thus touch) and we were away laughing.

[bamakin]

One other thing to check (I did read the huge-ass amount of text, but I thought I'd say it directly) is to make sure that the RCA surround on the plugs is actually contacting on both the amp and head-unit side. I had a good one once where the RCA plug outer wasn't actually contacting the socket; this meant that the small-signal ground was referenced through the chassis instead, which introduced alternator noise. Bit of a chomp down on connector to make it more oval (and thus touch) and we were away laughing.

I will check this out tomorrow thanks. I have got the interference right down now but its still present, but I only have rca to front channel on amp as when i add the rca cable to the rear channel the interference jumps up substantially. I have re-routed cables to make sure power lead is well away but made no difference. I also check all ground points. I noticed that the aerial was acting as a ground and also the headunit has its own ground so was not sure if I had created a ground loop there but made no difference when removing aerial connection. I also wondered if my 2nd rca cable is dodgy but i swapped them around and both work on either the front output or rear output ok with minimal interference (although still there slightly) but when both rca's are plugged in to headunit and amp the interference jumps up again.
Could it be the headunit playing up maybe??
Or maybe I need to buy more expensive leads? Just dont want to spend unneccesarily.

PS thanks to everyone who has replied to this thread! would be lost otherwise lol!!

[Gly]

what sort of head unit?
are the rca's internally fused on the heard unit?
i know some HU's had this and when the fuse went you would get feedback,

you can test this by shorting the rca neg to the body of the headunit

[bamakin]

what sort of head unit?
are the rca's internally fused on the heard unit?
i know some HU's had this and when the fuse went you would get feedback,

you can test this by shorting the rca neg to the body of the headunit

its one similar to this:
http://www.caraudiocentre.co.uk/prod...ri_p-25868.htm

When i touch the rca.s to the rear of the head unit body i get feedback noise.
I have quite a few times checked to make sure rca's have solid connection but need to check metal surround is actually contacting.
There is a fuse on the back of the head unit although i have never actually checked it!!

I will have another look when daylight cometh!!!

Just strange cos used same system on few different cars but this is only one getting interference.
Small price to pay though for having an awesome VR-4!!

[Fully]

Another option is to run your unit on a bench!

I normally do this on big job I have done in the past. Just to make sure nothing is faulty.

[bamakin]

Another option is to run your unit on a bench!

I normally do this on big job I have done in the past. Just to make sure nothing is faulty.

I wish I had done this now eh!!!
Will definately do it next time. Keep trying to get out to work on car but now its covered in snow!! This must be worlds longest job!

[wintertidenz]

The Pioneer units usually have a fusable RCA fuse that goes if you plug it in while the unit is powered on, not sure about the Alpines though.

Cheap leads can cause issues, another way of doing it would be to solder a ground to the outside of the RCA's on each end and ground them that way. Also check that there is no voltage or resistance differential in the grounds between the front and the rear of the car - if so, then you will get noise.

I would also suggest making a nice big ground off your battery as well if you are installing a larger system, or are going for SQ - just helps to eliminate any issues with your older factory ground.

[bamakin]

Whats the best way to ground the headunit as I now need to remove the wiring loom adapter ground and replace it with decent cable which is the same as I have used to ground the amp in the boot.
Can you just make a connection to the headunit body anywhere suitable? ie where screw can be fitted.

Cheers.

[VR457]

Best ground is to take a line direct to the battery terminal (-).

Pugme is right about checking RCA connections are secure on both sides.

The best way is to test each item in isolation on a test bench but failing that it's a case of trying different things and seeing what happens. One solution for a whiny BMW mentioned in Talkaudio was to wire in a capacitor between the battery and chassis!

[pitslayer]

Tin foil hat?

[wintertidenz]

Ground it on the metal chassis, either under a screw or somewhere else suitable. Then run it down to a point on the chassis, sand it down to bare metal, bolt it in, and just lightly paint over the top (to prevent corrosion).

Also ensure that your ground from the battery is good - I always do another ground from the battery straight to chassis with a 4ga piece of cable just to prevent any possible earthing issues.

[bamakin]

Ground it on the metal chassis, either under a screw or somewhere else suitable. Then run it down to a point on the chassis, sand it down to bare metal, bolt it in, and just lightly paint over the top (to prevent corrosion).

Also ensure that your ground from the battery is good - I always do another ground from the battery straight to chassis with a 4ga piece of cable just to prevent any possible earthing issues.

Thanks for the reply mate. This is my next job on the list.
I have also been looking at 6.5 inch speakers from the loudest.co.uk, they look decent enough to use as fronts. they say you can split the speaker to use them as components and have them together.
Have you bought any gear from these?

[wintertidenz]

I'm in NZ sorry! You would be best off buying a separate component set IMO. Sometimes they make compromises with the cone when they build the convertible sets.

[VR457]

Just compare prices and reviews on other sites. If the brand is ok and you're paying around £35 plus then it will probably be ok.

[bamakin]

Just an update for this thread....Firstly thanks for all the replies.
I first of all bought better quality wiring for the power and ground. I tested the new ground cable running directly from the battery but it made no difference so just used a bolt under my seat (as moved install from boot to under front seat also to see if this made any difference). Also moving the rca cables and power cable either on separate sides of the car or next to each other made no difference either.
However when i changed the power cable out it reduced the interference noise substantially. Once the amp gain was setup it is barely audible and cant be heard once volume goes past 1/2. Result!!! (of sorts!)
The only time I can hear it now is if I crank the gain up on the amp way beyond what i need. The other thing was the switches on the amp have broke for the hpf/lpf/off. i have to use a screwdriver to switch these over by poking it in the gap where the switch used to be. when switching modes i get interference too so hopefully when i replace this amp i wont get any interference.
I now have two infinity reference 9366i's 6 by 9's on custom parcel shelf in speaker boxes and 12" sub underneath so getting decent sound out now aswell as alpine headunit picked up off ebay 4 by 60 watts with three (4v) outputs.
nothing special here but sounds good. next month will be components and then trying to thread new wires through those damn rubber fittings for the rear door cables!! tried the other day but gave up!!

Thanks again everyone!

[VR457]

Well done! Sounds like your amplifier connection where the power lead goes in might be at fault. Try another amp if you get the chance.

[bamakin]

Well done! Sounds like your amplifier connection where the power lead goes in might be at fault. Try another amp if you get the chance.

Yeah im going to get shot of my existing one its lasted about 5/6 years so done well. i want a compact 4 channel amp that packs a bit of a punch. the search is on!!
any recommendations would be welcome. budget upto 150, watts 600 to 1000, 4 channel, as compact as possible.

laterz!!

[VR457]

JL Audio 300/4. Regulated power supply, means whatever the battery voltage it will still dish it out.

Will look up others depending on your price range!

[bamakin]

JL Audio 300/4. Regulated power supply, means whatever the battery voltage it will still dish it out.

Will look up others depending on your price range!

That amp looks awesome but bit out of what i can spend really. can push to 200 quid. thanks for looking though mate!!
ps i wont be telling my wife im buying a new amp lol!! secret purchase!!! i use the divide by 4 rule. if its 200 quid i will tell her it was 50! lol!

[VR457]

What about Vibe Blackbox Stereo 4 from http://www.caraudiodirect.co.uk/vibe...-stereo-4.html ?

A massive 4 x 100WRMS at 4 ohms. Proper, solid watts here.

Come to think of it, i might just get one for myself!