Need A Bit Of Advice From The Stereo Gurus

[DaveO74]

Hi peeps,

Im currently undertaking a rebuild/freshen up of my 33 gtst and part of the build is to fix my buzzing (alternator whine?) stereo after a crappy install a couple of years ago. Im putting in a new interior so I thought while i have the seats and door trims out of the car I may as well rewire the system properly and do a bit of sound proofing/deadening while im at it.

I've picked up enough dynamat stuff to do both doors and maybe a bit of the parcel shelf and I was thinking of using ccf foam/insulation which I have lying around from some older side projects. It is the stuff you get from clark rubber which is dark grey with the foil stuff on one side and is sticky on the other. I have around 5 metres of 5mm thick and 4metres of 10mm thick, So im thinking of using the 10mm in the boot area and to cover the rear seat area, rear inner guards and b pillars and then use the 5mm for under the carpet and maybe the roof.

I understand it will not work as good a dynamatting the entire car but will it still work for some deadening and quitening down a bit of road noise and exhaust noise (my car is a bit loud )

The second thing I wanted to ask is all of my stereo wiring runs on the passenger side on the floor literally on top of the wiring harness to the amp and back in one big clump. I have read in this section that this is the most likeley cuase for my noise problem so how should I rewire it?? RCA's down the middle on the drivers side and then speaker wires down the middle on the passengers side?? (centre console area) see pic below for current "dodgy" setup

And my last question is I have some 6.5" splits in the front doors and I noticed last night the have these little setting type switches on them like a cmos setting on your pc.

See below

At the moment they are set to "REF" which I gather just means a nuetral setting, is there a better way I should have these pins set. The tweeters can sometimes be a little "shrieky" if that makes sense when i have the radio up loud.

Sorry for the long post people and please forgive me if these are noob questions, im lost when it comes to this type of sound insulation and stereo wiring thing.

Thanks

D

[BundyBear]

Dave

Any sound deadnr helps a bit, even the tar suff painted on

just watch where trim panels fit on, the clips win't penetr8 the extra depth

for bigger bits like the roof I'd double up strips where room permits

Yes them RCA's could cause interference, run em up the middle on there own

The other main source of random noise is dodgy gound connections

Speakers look like the Xover is just mounted on the back,

Ref is just a flat/Neutral responce, assuming the 'screetching's' not distortion, knock it back to -1.5dB should take the edge off (-3.0dB is like putting in half the power)

Cheerz

Bundy

Edited January 27, 2011 by BundyBear

[Nanogrip]

In addition to BundyBear's post,

I think if the stock audio system had no whining before, then the whining now or recently is from poor ground to aftermarket powered audio systems, or from under-shielded RCA cables (or both), or from a really high power/leaking ignition system.  Maybe you can wrap the RCA cables with aluminum tape.  I try not to put any wiring in the middle of the car because they tend to rub the most, so I usually place them in the seams where the floor meets the sides.

The wiring that is on the passenger floor looks okay, I would probably braid them if I were doing something similar (it's just a habit, has not improved or worsen any of my audio quality).  You can improve it now by wrapping it in an aluminum tape, also watch out for rubbing, compression, shearing, vibration that will lead to cutting of the wires, etc. when returning the carpets, so secure them as best as you can.

This is a fun idea but probably not a good one, you can use foam injection behind some of the plastic panels to improve your sound quality.

Have a blast with it.

[DaveO74]

Thanks for the tips guys, this is the first chance I've had to reply.

What does the midrange presence jumper do? Anyone know?

I went and priced a few bits and pieces today like speaker diffusers, wow.....the guy wanted 200bux for two of them! Bit pricey IMO so I think I'll give the diffusers a miss and try and dodge one up use some of the ccf foam turned back to front. I reckon it will have the same sort of effect. I'm learning as I go so be prepared for more q's.

I may have to get some extra foam from Clark rubber if I want to do the roof as well I think, got out the tape measure last night and I'm a couple of meters short. Hopefully all the work will be of benefit

[mattis96]

i had problems with running my rcas down the middle, moved them to side no noise interference, just a personal experience

[BundyBear]

mostly It's not where you run your cables but what you run them with ( I picked the middle 4 Dave cause his pics showed nothn there)

I am curious what probs people had with cables down the middle, is it a 33 thing?

I got all my carpc cables (7-8 of em)down the middle with minor mods to the rear firewall, mainly cause PC are bad 4 interference so I want to keep them away from everything else

Ive had no rubbing or pulling from the seat

Edited February 7, 2011 by BundyBear

[sydking]

run the RCA and the power or ground at least a foot away, stopped my alternator whine straight away. my cables are running to the amp sitting under driver side front seat.

[Nanogrip]

I am curious what probs people had with cables down the middle, is it a 33 thing?

The rubbing I get is from the weight of the carpet on top of the wires (from my observation). There is always vibration between the carpet and whatever the carpet is on top of. Since the middle is farthest away from a solid anchored point, the middle moves most. The sides gives a nice amount of space and doesn't press or act on the wires as much. But every car and how everyone handles their wires are different. I hope I made sense.

[BundyBear]

Yea makes sence, runn'n from the front I tucked mide right next to the LHS of the tranny tunnel, then up and across to the RHS of the hump in the seat ( so it zigzagz) then back to a small notch in the removable part of the rear filewall, being down in the corners seems to keep the wires away from rubbing, stray feet and no lumps in the carpet. I always tape em down to keep em still(probably helps with rubbing 2)

mostly want'd to make sure there's no specific probs with the 33'z

4 the record I think down the sides is best and def. easier, but hey I've run em through the roof when required or outside the car for testing( love MSD !!)

& yes Everyone handles their wires different, which I think makes a difference

[DaveO74]

Thanks guys,

Well I reckon I've Sussex out a few things that will contribute to the noise I have been getting.

First thing I found was the earth for the headunit, it has had a thicker wire spliced in so as to make two earth points but it was attached to the gearstick bracket thingy which IMO is not ideal so I'll fix that up.

Secondly.........and this made me have a little chuckle..........when I had my sound system installed I did watch most of what went on but went for a 20min walk to get a bit to eat so I didn't see the entire installation. Turns out they used some nice 12 gauge wire along the floor to the amp and speakers but then they still spliced it into the standard tiny factory wiring so as to not go through the doors.

And thirdly the earth from the amp in the boot is only connected to the bracket thingy that the battery sits on, very rough I reckon so I've decided to redo the while system.

Just goes to show that you do not always get what you pay for!

[BundyBear]

Glad 2 help, don't think its been said but check the earth from the altern8tr, might need upgrading!

Just goes to show that you do not always get what you pay for!

unfortunalty true, like they say : want it done right ya gota do it yaself & don't take ya eye of the ball!

Cheers all

Bundy

[DaveO74]

Hey bundy what would I upgrade the alt earth too?

[Carbon 34]

yes, 4gauge wire to the mounting bolt of the alternator to the negative terminal of the battery , this will also help misfiring coil packs sometimes. the voltage won't drop so much

use care so the wires are secure and not rubbing anything.

and most average car radio/amp installs don't include running fresh wire to inside the doors, the labour time can build up very fast to do that. with some molex plugs in doors being a bitch to find room to run wires into.

I would ask them to ground the amp in a better location. some brackets are barely secure with more then a few spotwelds. not good for a lot of current transfer at all

[SPINR31]

seems i cbf reading all the replies ill just post how i did mine

Did the big 3 upgrade (Engine to Chassis, Alt to Battery, Battery Ground)

When connecting the terminals on the batt i scrubbed away any corrosion, and i sanded back a spot on the front right whell arch for batt ground.

i ran 4awg from batt through the firewall, under the carpet (down right side of car) and up behind the back seats.

i then screwed cap and t block to back seat, i grounded the cap to the seat mount.

amp is grounded to the boot release (i sanded the paint back)

rca's are going from head unit, around and under the carpet (where the front passenger sits) down the left side of the car under carpet and up behind the seats.

as for sound deadening i put 1/2inch hard compound foam from clark rubbers under the number plate, found i still had heaps of rattle tho so i glued the boot lid back to the fram using sikaflex glue..... and that fixed rattle alot

i havnt yet gotten to put sound deadener in yet tho but while your at it where the boot closes, put foam or rubber under the lip (around where the release clip is) and pretty much anywhere where there is 1 inch or less clearence (to accomodate flex)

hope this helped

[SPINR31]

Hey bundy what would I upgrade the alt earth too?

i wouldnt worry to much but it wont hurt

[SPINR31]

run the RCA and the power or ground at least a foot away, stopped my alternator whine straight away. my cables are running to the amp sitting under driver side front seat.

yer i ran power down one side, rca's down the other, amp ground is always >10cm away except where it is plugged into amp

[SPINR31]

pro tip: dont cheap out on wiring, use the good stuff like Rockford Fosgate

[Carbon 34]

pro tip: dont cheap out on wiring, use the good stuff like Rockford Fosgate

there are so many companies who make good stuff, like Rockford , just use name branded stuff and a really good installer, which is by far more important then the price points and brands.Rockford is average in comparison to what you can buy with lots of money , but in the long run will you hear the difference in a car doubt it.

pro tip 2

a cheap as chips patch cord will work and used by fly by night installers , but for how long, 2 days or 2 seconds, before the RCA falls off?

get a pro to intall it , somebody who will stand behind the install and not ashamed to show you how the wires are run if you ask them