Team-BHP - My weird experience with alternator whine (Alpine HU)

Quote:

Originally Posted by Tool (Post 804026)

any updates bro ?
i have HSk's too so if you need any help do let me know :)
will be happy to come by FM drive and brain storm :)
hope your problem gets diagnosed/solved.
Pankaj bhai is pretty good with his work.
hope this helps.

Hi Tool
I have dropped my car with him in the morning & he asked me to collect the same in the evening.
I shall be at FM Drive by 6 pm, I would be extremely glad to meet u if its OK with U .
My cell no is 9820609247.
We got the foll things checked

Alternator : No issues with it at all.
Amp & HU grounding was checked earlier : No issues with it at all.
RCA cables changed : No issues with it at all.

So I am for the time being extremely SAD
Thanks

the same thing is happening with me. only the rear speakers give a whine. earlier i had connected 75.4 amp to the rear jbl speakers and the sub. the whine was present. then i got a new set of components and a new amp.
now what i did is changed the rca and used the new amp for rear speakers and put the components and sub on 75.4. i thought that if its the problem with 75.4 then whine will come from components.
but still again the whine is from the rear speakers only. the amp is new. wiring is new and the RCA is also new. but the speakers are in close proximity to both the amps as the amps are mounted on the rear seat's back. it is because of this i am facing the whine?
also the RCA and speaker cables run from the corners of the car and the battery wires from the centre. both amps are grounded in same place and the HU is grounded to the metal body behind the dash. i have not used the factory ground wiring.

Quote:

Originally Posted by Technocrat (Post 804548)

Amit your case is different from Shuvc's

He is giving same channel to front & rear & only rear is giving whine.

Btw I have my amp in front & irrespective of the speaker location & type I still get whine but now that I have got used to it, I am not bothered anymore :p

YA techno you are right. i got shuvc's problem. i was just trying to figure out whatever the combinations are the whine is always there from rear speakers.
i have heard the whine in your system , its quite audible. it can be sorted out by rewiring or the HU rca grounding. but i have a whine which is not loud. its very minute. during the day time its so less that u have to hear carefully to notice it. but when u turn out the headlights and ac at nights its louder.
i can conclude that the whine has 100 reasons to creep in. it loves the ICE too much it seems. the one out of 100 reasons is very difficult to capture.:deadhorse

This annoying whine doesn't want to go away it seems. Spent around 3 hours at Driven doing the following:

1) Re-routed the Power and RCA from opposite sides.

2) Tried RCA grounding method.

3) Connected the HU ground cable in the stereo wire harness to the amp ground at the amplifier end (not the car body end , hope it's correct ).

Still the noise is there. It seems to be a bit less but that could be my tired brain playing tricks on me :confused:. So will go for Audison RCA today.

BTW , I seem to have run into a strange problem. Since my HU has a single pre-out only, I use Y-connectors to split the signal for the amp (gto75.4) front and rear inputs. From the HU I have selected the preout as rear.

Now my front and rear fader works , but when I shift balance completely to the right I get only sub output and completely to the right only rear speakers work.

Is this normal or have I blown one channel of my HU's pre-out while playing around with grounding :Shockked:??

Quote:

Originally Posted by Sam Kapasi (Post 297108)

So here’s a weird experience I had.

I’ve had this barely, just barely audible alternator whine from all my speakers. It’s not annoying, just can be heard if you concentrate hard on empty passages during the music.

Grounding is improper..I'm sure your instal inside your car would not have power wires and speaker wires crossing at any point etc.. Any power wire crossing a speaker wire will / can lead to this whine..

Quote:

Originally Posted by Rudra Sen (Post 297160)

But Navin, alternator whine was there..may be very little....

How to eleminate that totally? Because I also have it..

Quote:

Originally Posted by low_bass_makker (Post 297199)

It can be check by powering up the system from a external power like a battery and all the things even the hu amp every thing....then start the engine and see that there is noise or not ...if it is still there then problem lies some place else....if it goes away then the problem lies in the power wiring...to rectify it we need to connect back every thing one by one starting from amp which are less prone to this type of noise problem....if it comes back u need to put a noise suppressor in the path of the power supply to solve it.....if the external power supply test did not helped then no noise suppressor could help u in this case....make a shorted rca leads (take rca plug and short the both ends in the plug) connect it the amp input which make the amp to behave like there is no input there ...after that check if there is some noise or not if it is there then the amp is fault....replace the amp to verify that .....or even changing of the earth connecttion could help a lot....now one thing more the RCA leads could be the culprit also try replacing them can also help......the final thing take out the hu from the mounting place where it is installed while it is running...check that the noise is still there or not ....if it goes away the u have to shift the HU or try to ground it from any other place.....hope this helps....

A simple way to check whether the system generates the whine or not!

Quote:

Originally Posted by navin (Post 751343)

I think you got a ground loop. ground both amps and Hu to same point. ensure that the ground is corrosion free.

I hope your RCA and power cables do not run parallel to each other.

I think this is a common mistake done by most installers!

Quote:

Originally Posted by DerAlte (Post 810968)

Check the connection from the Y-cable to the amp. Most likely both the 'right's are connected to the 'front' inputs of the amp, and both the 'left's to the 'rear' inputs of the amp, or vice-versa.

The Y-cable splits 1 RCA channel into two. So two channels are split into 4.
Now one pair , originating from 1 RCA goes into front input (speakers). The other pair goes as rear input(sub).

Do you suggest I connect it so that one end of the Y-cable goes into front and one for rear and same for the other Y-cable.
Something like a cross connection??

Quote:

Originally Posted by Sam Kapasi (Post 297108)

So here’s a weird experience I had.

Alpine HU, 2 amps, Van den Hul RCA, 2 different kinds (silver for front and carbon hybrid for rear), wonder-solder and terminated with neutrik.

Right from day one, I’ve had this barely, just barely audible alternator whine from all my speakers. It’s not annoying, just can be heard if you concentrate hard on empty passages during the music. In fact most people wont hear it.
I have always attributed it to the fact that in effect I’m using home audio cables(no matter how good they are) and perhaps the shielding may not be as strong as a car-dedicated cable and hence the ground loop/whine rejection may not be at par with some cables more desgned to reject in-car interference.

Quote:

Originally Posted by headers (Post 811005)

Hey headers,

Thank you for your advice on a point I raised a year and a half ago. :) I installed that system myself.

I have 3 questions.

1) You didn't read this thread, did you?
2) In fact you haven't read anything in the ICE section so far have you? lol. 3) Got you, didn't we?

Love,
Sam

Quote:

Originally Posted by sonic_boom (Post 811041)

The Y-cable splits 1 RCA channel into two. So two channels are split into 4.
Now one pair , originating from 1 RCA goes into front input (speakers). The other pair goes as rear input(sub).

Do you suggest I connect it so that one end of the Y-cable goes into front and one for rear and same for the other Y-cable.
Something like a cross connection??

Hare Ram! Hello @sonic_boom bhaya, doesn't that mean you are putting the Left (or the Right) to both the Left and Right of the Front channel of the amp? Your "1 RCA" = 1 channel, left or right!!!

What you should be doing is this (use stickers to mark the cables / connectors, so that you don't get confused):
1. Left channel RCA coming from HU gets split into L1 and L2
2. Right channel RCA coming from HU gets split into R1 and R2
3. L1 + R1 should go to Front channel (L+R) of the amp
4. L2 + R2 should go to Rear channel (L+R) of the amp

Usually RCA sockets are color-coded: black=left and red=right. Don't worry if the thing is swapped L to R - by shifting balance you can detect this, and put them correctly. Good luck!

Quote:

Originally Posted by Sam Kapasi (Post 811054)

Hey sam,

Well for starters..how could i post if i didnt read this thread? LOL

I do read the ICE section..but dont post much as there as many of you experts doing the job for me..ha ha

Cheers