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SaabScene.com Premium Member
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Discussion Starter #1
OK guys, finally decided to bite the bullet and install my amp today, I bought a Vibe 4 channel amp last year and bottled fitting it, I also fitted vibe 6x9's running off the rear speaker cables but they were crap.

So I installed everything and ran the live feed outside of the car as a test connected to the battery before I battle the firewall.


My vibe amp has high & low inputs, I bought a RCA converter as well, I tried both high & low inputs and each time I'm getting a popping sound in the speakers. Any ideas? Is it a grounding issue, I googled it earlier and read that popping is not good - so I stopped what I'm doing. I also took the remote feed off the 7.5a rear camera fuse in the rear fuse box, any other options as I dont have any fuse taps - might have to buy one I think. But I'd rather take the remote feed from a wire rather than the fuse.

Sound wise it works great! Loads of bass in the 6x9's but I think I've compromised the bass in the doors by taking the feed from the FL & FR inputs into the amp, is it worth trying the RL & RR inputs for same sound quality?

I'm knackered and my back is killing me - those cables from the stereo to the Saab amp are a real ***** to wire up - they are tiny!

Cheers!
 

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can bus puts noise on the power supply of the car most amps filter it out but some don't
a good ground & a ground loop isolator on input signal should reduce it but depending on the amp depends how much
 

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SaabScene.com Premium Member
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Discussion Starter #5 (Edited)
Cheers pal, I went the cheap option and put a couple of ferrite rings around the RCA's - made no difference, going to try an isolator tomorrow and maybe find another ground.

All fitted today! All in all took me...wait for it....12 hours, but I was cautious with a big f'in C! So here's the deal with fitting an amp to a facelift Saab 9-3. (No pics sorry, it was too much hard work and I really needed to concentrate). My amp has high & low inputs, I tested both and couldnt tell the difference in sound but opted for low inputs as it was a tidier install.

1) Firewall access is the same as pre-facelift for the Amp power cable.
2) Getting the cable to the boot is a doddle, just remove the glovebox and follow the door plastics to the boot.
3) Fitted new Vibe 6x9's
4) Tested the pre-amp Front Left & Front Right connected to a Line out converter to RCA.
5) Speakers sounded awesome but the front & door speakers in the car were compromised as I was splitting the input from the head unit, so...
6) I then tried connecting to the Rear preamp connections from the head unit - same affect sound wise and the fronts are back to normal. So I've left the new amp feed off the rear pre-amps and the only downside is that the small rear speakers no longer work haha what a shame!

- So word of advice - no need to take the feed from the fronts, the rears are just as good.

7) Connected the remote turn on to the Aerial remote turn on in the right hand side quarter panel (I think Hamster quoted this previously so thanks! I really didnt want to use a fuse tap. The aerial remote works fine as a remote turn on to the amp.
8) Grounded the amp under the OEM amp in the boot, and I wonder if this is why I'm getting the tap tap tap sound in the speakers.
9) I've screwed the amp to the carpet for the time being, just keeping an eye on heat, I might fit it vertically along the left hand side but will need some MDF behind the carpet to hold the amp in place.
10) All fitted and reconnected the battery.

So sound wise, WOW - I've had these 6x9's in the car for over a year connected to the rear speaker cables and it's like they've just had 10 cans of red bull - they've come alive! The sound is so rounded now, quality is amazing. It just fills the car. I need to get some dynamat or something similar to help with the vibrations in the rear parcel shelf as I'm sure I could increase the gain if I wanted.

Really surprised to be honest, I wasnt looking for a boom boom effect and the 6x9's give out so much power and bass.

Really chuffed I done it, it was an experience and has brought me back up to date with installing amps. Just need to sort the speaker click (which you cant hear when playing music anyway).

I think all in all cost me £100 for everything, I bought the amp & speakers in the halfords sale last year and what a steal for a change!
 

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SaabScene.com Premium Member
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Discussion Starter #7
how do you eliminate noise on the ground cable then? The ground loop isolator maplin sell is only specifically for the RCA's, will ferrite rings sort it? Mine makes the pop even with the RCA's not plugged in, I tried a different ground and still does it.
 

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well done on your install mate:thumbsup:

whilst ferrite cores are useful it does depend on how bad it actually is. we fit these cores very close to the transformers and also use something like this http://www.ebay.co.uk/itm/Legacy-35A-35-AMP-In-Line-Car-Audio-Noise-Suppressor-Ground-Loop-Isolator-/370781352113?pt=UK_Cars_Parts_Vehicles_Terminals_Cabling_ET&hash=item56544a70b1 in the circuit as we have a lot of noise especially when linking into the canbus with various equipment, and cheap is not always the answer, also if you have an RS local try them
 

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What works but I can only find small ones is the old chokes that radios had in the old days to suppress the alternator noise
Ground loop isolator is a isolating transformer 1:1 ratio input primary output secondary

With no rca's fitted the input will act like aerials for noise so it should reduce the noise with cables connected even if radio is on min volume (no signal)
 

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Cheers pal, I went the cheap option and put a couple of ferrite rings around the RCA's - made no difference
phono (rca) cables are screened so if the ferrite's made a difference I would of suggested replacing them coz if the screen isn't working then its acting like an aerial

could try the ferrite on the 12v cable & maybe remote as the noise is on the power cables, checking the ground is to reduce the possibility of the amp passing current down the rca cables / case / any other ground it can find
just think of a bad light earth it uses the other bulb circuits as a ground hence multiple lights on & random behaviour
 

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SaabScene.com Premium Member
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Discussion Starter #12
OK so I tried another ground (off one of the rear seat belt bolts) - no difference, tried ferrite on 12v, ground and remote - no difference. I even went to Maplin and they very kindly let me test (yes!) a RCA ground loop isolator and that made no difference.

Problem is defo coming from the RCA's, when I remove them from the amp no noise but when I fit them defo tap tap tap noise. So it's either my LOC or the quality of the sound from the Saab amp, I might try the post amp cables and connect to my high level input....if I have any energy left.
 

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SaabScene.com Premium Member
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Discussion Starter #15
No the Loc just has 4 speaker cables and 2 rca's with a big barrel in the middle.

I wonder if a LOC with a ground will fix this. Hmmm
 

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may I suggest something :) the noise you are getting is induced along with making sure the amp has a good ground... also run a short wire of around 16g to ground from the head unit case to the car body, (could also try on saab amp)

make sure the RCA cables are not run next to any vehicle electric cables nor the power cables to the amp, RCA cables are of a good quality and you have good shield grounds.............think haloween mentioned amplification/aerial effect

just a thought m8 thinking basics first ;)
 

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Discussion Starter #17 (Edited)
Cheers Kez I'll give that a shot. It was making the same noise when I had the 12v cable running outside of the car so that rules out that I think. The RCA's are running in a different direction. The problem is coming from the RCA's so it's earth the quality from the amp or headunit like you said. I'm also getting engine start motor feedback in the rear speakers when I start the car.

I bought a LOC with an earth cable today from Halfords, it was a million zillion times worse, so back to square one. I'm sure I'll get to the bottom of it. Sounds amazing otherwise!
 
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