If you need healp with sound issues and live in grimsby/cleethorpes area then holla at me?

Need advice on sound installs to speakers to fitting a headunit then gizz a shout!,im not the best and dont know evrything but i think i know enough to put a smile on any owners new sound equipment!!!

Heres one for you:
Specs
Kenwood 7" indash dvd/tv/cd/gps headunit with seperate reciever boxes.
Infinity reference components
JBL GTO AMP 4000 500W AMP running in tri mode for sub and components
15"JBL SUB in ported box.
Infinity reference 6x9s

power cables down the right 0guage
rca's down the left
speaker cables up the middle

If i turn the gain up slightly on the amp on any channel i get feedback that goes up and down with the revs(that annoying high pitched whine)

The amp had 0guage earth to a good clean earth point.

Whats he problem?Is it worth me earthing the headunit to the amp and the reciever unit?

I didnt want to use a ground loop isolator as i hear you lose a lot of signal and sound quality.


Any ideas dude?

i could use a hand in the future too. not big into subs and what not but want a decent system in my mk2 but without hacking into door cards/parcel shelf. and without spending megabucks

Lowlifedubber wrote:Heres one for you:
Specs
Kenwood 7" indash dvd/tv/cd/gps headunit with seperate reciever boxes.
Infinity reference components
JBL GTO AMP 4000 500W AMP running in tri mode for sub and components
15"JBL SUB in ported box.
Infinity reference 6x9s

power cables down the right 0guage
rca's down the left
speaker cables up the middle

If i turn the gain up slightly on the amp on any channel i get feedback that goes up and down with the revs(that annoying high pitched whine)

The amp had 0guage earth to a good clean earth point.

Whats he problem?Is it worth me earthing the headunit to the amp and the reciever unit?

I didnt want to use a ground loop isolator as i hear you lose a lot of signal and sound quality.


Any ideas dude?

Hi, first thing that comes to mind is this reciever box?? is this for tv or gps??
and yes you are right about the earth loop,id recomend each gadjet that has its own power source to have its own earthing point.

With regards to the wining noise when you turn up your gain levels, is the amps source of sound (aux) direct from the head units aux output or from speaker output to amp as a high level input?

im asuming you have the auxilery lines split respectivly to each amp, or if your headunit has a more than 1chanel output via aux (i.e. aux #1 = sub, aux #2 = rear amp, aux #3 = amp front etc...). with having one source to feed a few highly powerd amps will lower the output feed i.e splitting the signal reduces the output at the end of each cable, not a huge thing to wory about but may make a difarence in performance of an install if ur running a number of amps.

lewis1641 wrote:i could use a hand in the future too. not big into subs and what not but want a decent system in my mk2 but without hacking into door cards/parcel shelf. and without spending megabucks

Ye that shouldnt be a problem mate, you thinking of running any amps or just uprating speaker and cabling to headunit?

probably just upgrades. see how the finances are

The headunit reciever box is just the gubbins that supplies the video source to the headunit recieves signal from the camera and sends a video source to the second screen in the centre console.

The whining noise was there with the old headunit too.
All rca leads are run down the same side of the car and each is coming out of there own 5v preout as the headunit has 6 preouts including a mono output for the sub.So no dodgy high level convertors are being used from the speaker wires.

Regarding the earth do i just run a single core wire,attatching it to the back of the headunit,to the reciever box and then through to the amp so any earthing doesnt occur through the rca leads?

Cheers for the help dude

Lowlifedubber wrote:The headunit reciever box is just the gubbins that supplies the video source to the headunit recieves signal from the camera and sends a video source to the second screen in the centre console.

The whining noise was there with the old headunit too.
All rca leads are run down the same side of the car and each is coming out of there own 5v preout as the headunit has 6 preouts including a mono output for the sub.So no dodgy high level convertors are being used from the speaker wires.

Regarding the earth do i just run a single core wire,attatching it to the back of the headunit,to the reciever box and then through to the amp so any earthing doesnt occur through the rca leads?

Cheers for the help dude

Id quite like to see this install in person as it sounds very much my typ of install

For earthing use cables that have an equivilent transfer rate as the power cables (i.e useing 4gauge cable for all amps power source then use the same for earthing) but try and make the earth cables as short as possible............ with regards to the transfer box im windering if you are getting the interfierance from the camera i.e camera casing (if metal) earthing through the screws/rivets to the boddy and transfering the static charg down the cables to the transfere box in turn sending it to the headunit/amps/speakers etc. its just a hunch but is bound to be a realy silly thing that could have been overlooked.

and no probs dave, il be up for anything you throw at me (soundwise lol)

Well the camera is mounted on the front of the car hidden under the numberplate and that is on plastic so no fear there.
Ive used 4guage for earthing and also for the earths
The earths are no more than 150mm long.

When i installed it i went through everything with a fine tooth comb,no choc or scotch locks were used anywhere.All cables routed properly,all new good quality branded cables and rca's.
Fused as near as the battery as possible etc.

Im normally good with this sort of thing as ive been doing them for years but this one is a pain in the arse!lol

Have a look here at the bottom of the page for pics and stuff

http://www.lowlifedubz.com/forums/viewtopic.php?f=43&t=2378&start=15

that is a comprehensive install there dude,im impressed,but otherwise it looks like all the procedures/do's and dont's are in check and am having trouble thinking of posible interference issues

noticed the gto amp is mounted to what looks like squared steel rods? is there a posibility that the rods are toutching the chassy? any cables that are chafed/scored with any of the core visible that is making contact with the chassy? cant realy think of anything els dude sorry, but hope you manage to finde out what is causing the interference coz youv got me stumpt lol.

gd luck

Aaaaah!You could have a point there dude.Its mounted to the floor with some 15mm chrome box section i cut at a 45deg angle and is drilled and tapped to he floor.
The stereo will be going away for repair this week for an unrelated matter,but when it gets back i will try it with the amp off the amp rack and see if it makes any difference.

Cheers for that

no probs dude,its just a hunch anyway, if it is then all you gotta do is have a small bit of wood or plastic inbetween the amp and the amprack to insulate the amp from the "amprack" (that was a mouth full haha). might even be worth giving it a go with another headunit like, never know but might get a difarent reaction from the other components of the install!

fingers crossed dude

Cheers dude,will report back

Lowlifedubber wrote:Cheers dude,will report back

Any results yet mate?

No not yet dude,ive got to send the headunit away to be repaired as it packed up after 2 days(damn ebay seller lol) but it will be back soon.Hopefully wont be too expensive either!

ok bud no problem,keep us updated ye

nothing like been thrown in at the deep end shooz

caistor_bmx wrote:nothing like been thrown in at the deep end shooz

True,but sometimes can be the best way to learn

harry your good with sound though bud. genious infact, that sy i give my subs to you to sort out when i have them. but i've passed having them now.

subs or no subz mate you know what im like,game for anything audio no matter what type of trax you listen to

got my hands on a sub people, check the clasifyeds section for details in audio