Head unit woes! / Amp / Components / Relocation of HU!!!

[SeanyK]

Hey folks! What can I say, not been a good day in terms of audio!

I had fitted yesterday;

FLI 900s 4 Channel Amp / Fusion 6.5" Components
Vibe QB69's / Fli wiring kit etc.

The amp has high level inputs, so thats what is being used.

Got in the car, could hear a high pitched interferance type noise when the volume was on 0! It went away with the stereo up, well, still there but the music drowned it out, but thats not the point!

Anyway, went back today to the fitters, who said it's the radio and this happens with this 'high level input' type setup sometimes, and how it's not ideal etc - which ok to be fair he is right, but i've had a similar setup on my old cupra running fine with no noise.

Anyway, he mentioned to try some speaker level to RCA along with noise suppressor etc

So I bought the stuff, tried it, same thing albeit a different sort of interferance!

So now, I have no sound, and am annoyed at having to book the car back in to the stereo shop.

Im now starting to wonder if it's worth asking them to somehow install my old Sony head unit at least that had RCA's and all the normal stuff (USB etc), and would probably 99% get rid of the above problem, but what a pain, £150 down and no sound!
Gonna ask them to see if it will fit in glove box or something, mind you if I was doing that from the start I wouldn't have bothered upgrading the speakers, i'd have just gone the 6x9 route powered by aftermarket stereo and saved myself a big wad of cash.

Oh well, you live and learn.

 

[SeanyK]

For my own curiosity - I decided to plug the iso connectors into my old Sony head unit, and ran a set of RCA leads from the head unit to the amp.

Voila - no interferance noise. (although it would mean running the cables properly obviously but it was just to prove a point).

So if they can't eliminate the noise thats the only option.

 

[Dan1.6]

i maybe abit confused about the aboive and im sorry if i get this wrong il just delte the post if i am but can't they adapt the standed head unit for rca adaptors the lad who owned my car before me said he did it wouldnt this work?

 

[SeanyK]

Hi mate,

Basically, you can get rca convertors which avoid the need to use the speaker level inputs of the amp, but I tried that and there was still an interference noise.

At the end of the day, any sort of convertors like that are never going to be any good, but the sound was good enough for me as long as they sort the stupid noise out, if not, it looks like a head unit relocation job!

 

[Dan1.6]

fair enough then cant really say anything agaisnt that

just good luck with it mate and i hope it works out well for ya

keep us posted

 

[sparkie1984]

not something like a poor earth mate?

 

[SeanyK]

I guess somewhere it could be mate, I admit i've pretty much given up on trying to suss it myself, I paid £150 for it to be installed yesterday, and granted the job is so so neat and tidy, but it's not proper if it has this problem, and really they should fix it free, whether they will is a different issue, it's booked in next week (midweek) so I guess I will wait and see.

Annoying thing is, I did my last install on my old MK3 years ago from start to finish, it wasn't the neatest job around but it worked perfectly for 3 years without a hitch! And im not even very good at that sorta thing! This time I thought i'd pay to have it done and that happens lol.

 

[sparkie1984]

well i have a high level input on a cheap sub made by fli i think, its good as gold, no noise nothing

on mine the high level input that plugged into the amp had a cable for ground too, has that been grounded? not to the same ground as the amp power supply either!

theres a guide on here on how to install it yourself, may help you fault find a bit?

 

[SeanyK]

Hey mate, thing that makes me not think it's an earth problem, is that it works with no noise on RCA's, im gonna give back to the installers to fix next week, if they can't do it im gonna get them to give me some money back and i'll try and fix it myself.

 

[antnee]

I get alternator whine on mine, but I need to try moving the earth cable, as its being shared with other stuff

 

[Adam R]

right, first off read my thrwad about audio in my sig.

next :
1) what phono cable are you using from the RCA converters ? is it shielded ? twin or tripple sheilded ?
2) which side do you run, power, signal ?
3) where is your amp earth ?
4) what RCA converters are you using?
5) have you got more than 1 earth in the system ? if so where is it ?

 

[SeanyK]

Hi Adam,

Basically they fitted it all so I have no idea where they have ran the wires, I know they used a FLI wiring kit though that was definately enough power for the job.

1) There was no phono cable initially used as I was just using the speaker level inputs of amplifier, only reason I bought RCA convertor was to try that to see if maybe the speaker input on the amp was faulty- when I did, the phono cables were just gold plated autoleads ones from Halfords.
2) Again, not sure as the guys fitted it.
3) Same... (but looks like it's going to the rear light cluster or that direction I think)
4) As 1, but they are Autoleads ground loop isolator / rca convertors.
5) Same as 1


When I did my build on my MK3 Ibiza about 4 years ago, I had no issues whatsoever, it wasn't neat in the boot thats all, I had a Sony xplod amp, front components and a Pioneer 12" Sub, I used the earth in the rear where the seat belt point and used average speaker cable - this is much better kit but seems to have issues!


I starting to think I should have just done it myself, but to be fair, the guys who fitted it are a proper car audio place, been around for years, I guess it's wait and see what they say on Wednesday, but I will keep you all informed as to what it is.

As I mentioned earlier, I quickyl connected my old sony head unit to the iso leads (disconnected OE stereo) and when using RCA leads from the back of my old sony stereo into the amp there was no noise, so it might eliminate most things by that thought... Pointing at a problem with the OE head unit itself maybe?

I think they said they might tweak the gains, but i'll be leaving the car with them all day to fix it.

 

[M87NER]

i had this exact same problem with mine..... noise suppresors do jack .

mine noise has now gone 95% , with my standard headunit i have connected the hi level - rca converter and earthed the converter to my headunit and this made the noise reduce, so have the rca running to my amp,

 

[Adam R]

Hi Adam,

Basically they fitted it all so I have no idea where they have ran the wires, I know they used a FLI wiring kit though that was definately enough power for the job.

1) There was no phono cable initially used as I was just using the speaker level inputs of amplifier, only reason I bought RCA convertor was to try that to see if maybe the speaker input on the amp was faulty- when I did, the phono cables were just gold plated autoleads ones from Halfords. thats your one of your problems. that stuff is not shielded and will get loads of noise (i found this out the hard way)
2) Again, not sure as the guys fitted it.
3) Same... (but looks like it's going to the rear light cluster or that direction I think) thats not good, you want to do it on the spare wheel stud as this is alot more heafty
4) As 1, but they are Autoleads ground loop isolator / rca convertors. if you buy crap cheap ones these will be no good. make sure the ones that are used have variable gain adjusters on them
5) Same as 1 if they ran extensions on the standard HU output down the side of the car, then this will also get alot of noise, also check for the signal next to power as i recon this is the case


When I did my build on my MK3 Ibiza about 4 years ago, I had no issues whatsoever, it wasn't neat in the boot thats all, I had a Sony xplod amp, front components and a Pioneer 12" Sub, I used the earth in the rear where the seat belt point and used average speaker cable - this is much better kit but seems to have issues!


I starting to think I should have just done it myself, but to be fair, the guys who fitted it are a proper car audio place, been around for years, I guess it's wait and see what they say on Wednesday, but I will keep you all informed as to what it is.

As I mentioned earlier, I quickyl connected my old sony head unit to the iso leads (disconnected OE stereo) and when using RCA leads from the back of my old sony stereo into the amp there was no noise, so it might eliminate most things by that thought... Pointing at a problem with the OE head unit itself maybe?

I think they said they might tweak the gains, but i'll be leaving the car with them all day to fix it.

i recon its the rca converters they used.

if you where nto so far away i would have told you to bring it to mine and i would do it for you for free.

 

[SeanyK]

Hi mate,

They never used RCA convertors, they wired the speakers into the high level inputs of the amp.

That was me after they fitted it who tried the RCA convertor/ground loop isolator thing, I tried it to see if it would eliminate the noise that was happening from the original setup.

I appreciate that offer - i'd have been there in a shot lol! But then after paying £150 for them to fit all that stuff for me, i'd like to think they should do the job properly when I take it back there on Wednesday - if I start digging up speaker wire, it's £150 wasted as I might as well have done the job myself

 

[SeanyK]

Alright lads,

Update - it's now pretty much fixed, there is still a noise but it's not really noticeable anymore unless your listening out for it.

Apparantly they used a Kenwood ground loop isolator or something... and that must have fixed it?