[vishnuvijay]

Originally Posted by DerAlte

Hi Vishnuvijay,

A few questions before anyone can figure the problem out:

1. Which car? (You have a Wagon R and an OHC listed in your profile)
2. Which sound source is producing the hiss: FM or Audio CD or MP3?
3. Did you listen in when the installer changed the HU to show that "everything was normal"?
4. What settings have been made on the HU (Bass, Treble, Fader, Equalizer, etc.)?
5. At what volume level is the hiss just audible? What is the normal volume level that you hear music at?
6. Is the hiss same from the front as well as the rear speakers? You could fade fully to the Front or Rear to check
7. (Sam has already asked that)

hi deralte,
1.the car is 2003 ohc vtec type II.
2.mp3 is producing the hissing. i think fm is also producing it, but fm always has disturbances.
3.yes i was with the installer and i had listened to it. there was noise.
4.the sound persists even on eq-flat and loud turned off.
5.the HU has max volume of 62. hiss can be heard even at 20 or 30.
6.hiss is same from both front and rear as well as left and right.

thank you.

[vishnuvijay]

Originally Posted by Wimwian

I was having this hissing problem whenever the engine was on... the noise used to increase with the engine RPM and v.v. My installer had no clue which component was responsible, so he went for the age old solution - the trial & error method. Changed each part one by one and finally narrowed it down to the HU... the dealer changed the HU and now everything's OK [except the amp tuning has gone haywire in all of this :-(]

but i checked it with another HU of the same model and it still had the noise.

Originally Posted by saintsinner

i had this problem too.. but then i grounded the RC cables.. and its fine now

hi saintsinner, what does "grounding the rc cables" mean?

[gunbir]

Originally Posted by low_bass_makker

I am quite sure this would not be the reason.

You have your opinions, I have mine. You are welcome to yours. Doesn't mean you're right.

Originally Posted by low_bass_makker

Ya I tend to agree and his magic touch does wonder to the sound also..

Thanks, It's not magic... I have actually tried to train many TBHPians on how to set their amp gains... but they're just plain lazy and prefer me or Jb doing it.

Originally Posted by Sam Kapasi

Like navin said, while an RCA cable can pick up enough hiss to be audible, simply because of the peak to peak of pre amplified signal and the fact that the hiss stands an equal chance of being amplified, I have my serious doubts that changing the speaker wire is the answer.

I don't think the audio signal, post-amplification from the HU, is susceptible to audible hiss pick up.

It may change the quality of the sound, but I'm pretty sure changing the speaker cable is not going to get rid of the hiss.

Sam, I thought you would get what I was hinting at.

Considering he doesn't have an amp, and based on his inputs... The stock OE cables are the culprit. There is a leak in his OE cabling. Changing speaker cables from the HU to the speakers will fix the issue.

Ciao

[vishnuvijay]

thank you gunbir. i'll try changing the cables. can anyone please tell me what "grounding of cables" mean?

[vishnuvijay]

will changing the cables to better one improve sound clarity drastically?

[low_bass_makker]

Originally Posted by vishnuvijay

but i checked it with another HU of the same model and it still had the noise.

Sir what type of noise are you getting is it like the alternator whine which changes with engine speed or it is like hiss speaker make when there is no audio playing and the volume is set to full.

[low_bass_makker]

Originally Posted by vishnuvijay

will changing the cables to better one improve sound clarity drastically?

NO , changing the speaker wire would not change the sound. But the RCA could make a difference..

try this, this is the grounding the RCA

[gunbir]

Originally Posted by low_bass_makker

NO , changing the speaker wire would not change the sound. But the RCA could make a difference..

try this, this is the grounding the RCA

LBM, some things you should consider before giving the above advice:

a. He doesn't have an amplifier.
b. Il n'a pas un amplificateur
c. Non ha un amplificatore
d. Uske paas amplifier nahin hai


@VishnuVijay, "Grounding of Cables" implies there is a short somewhere in your cabling. Since the automotive electrical system is based on negative ground, if any positive cables are exposed and touching with the car's body, there is a short which is referred to as "grounding of cables" sometimes.

If this was happening on your current OE speaker cabling, your HU wouldn't be able to play audio as the internal amp would get shorted. Whats possibly happening is that your OE cables are picking up noise somehow.

[DerAlte]

Originally Posted by vishnuvijay

hi deralte,
1.the car is 2003 ohc vtec type II.
2.mp3 is producing the hissing. i think fm is also producing it, but fm always has disturbances.
3.yes i was with the installer and i had listened to it. there was noise.
4.the sound persists even on eq-flat and loud turned off.
5.the HU has max volume of 62. hiss can be heard even at 20 or 30.
6.hiss is same from both front and rear as well as left and right.

@Vishnuvijay, everything seems to be OK there. If it is appearing on all speakers, it is a common source in/near the HU. If it was present even when the HU was changed, it is not IN the HU, but near it. Most likely improper grounding of the HU, or improperly fed battery power.

And no, FM (when tuned to a station) is not normally noisy like AM radio. Another possibility is your MP3 CD, but that can be easily eliminated by playing another CD, preferably audion CD. I am sure you have already done that.

The only thing left to check is if the hiss is significantly present when the volume is set to 0 - that would be an indication of what Gunbir is trying to point out.

Gunbir, you have a point there. But, if the speaker cables are picking up noise, that hiss will be volume-independent, i.e. the speakers will hiss even if the HU volume is at 0, and the 'hiss' source should be delivering significant power to the speakers. Unless there is a wiring mess leading to RF feedback into the HU amp section.

I think the instaler should be shaken awake to have a good look at the wiring - power, speakers, antenna, grounding, everything. They wouldn't normally look beyond the first 6 inches of any cable.

In another post here, someone had a similar problem which was solved by the installer putting balun chokes (I think it was that, but I am not sure, since pics were impossible) in the power line to the HU.

[low_bass_makker]

Speaker cables cannot pick up any interference and pass it on to the speaker.It can happen on RCA level where the signal gets amplified but it can be the case that the speaker wire touching the chassis of the car which is causing this problem.

But since I asked before is it a hiss or a wine. both are different. and I am expecting the clarification here.

[DerAlte]

Originally Posted by low_bass_makker

Speaker cables cannot pick up any interference and pass it on to the speaker.It can happen on RCA level where the signal gets amplified but it can be the case that the speaker wire touching the chassis of the car which is causing this problem.

But that would cause the amp's overload circuit to act, no? Also this would be localized to THAT speaker whose cable is touching ground.

Originally Posted by low_bass_makker

But since I asked before is it a hiss or a wine. both are different. and I am expecting the clarification here

To add fuel to the fire, is it "sssssssssssss", "khhshshshshshsshsh", "zzzzzzzzzzzzz", "chirrrrrrrrrr" or "cheeeeeeeeeeeen"?

[navin]

Originally Posted by vishnuvijay

1.the car is 2003 ohc vtec type II.
2.mp3 is producing the hissing. i think fm is also producing it, but fm always has disturbances.
3.yes i was with the installer and i had listened to it. there was noise.
4.the sound persists even on eq-flat and loud turned off.
5.the HU has max volume of 62. hiss can be heard even at 20 or 30.
6.hiss is same from both front and rear as well as left and right.

Can you try a Hu of another make and model.

I suspect a poor installtion. Some wire (it really could be any wire, even the antenna wire) or even the chassis of your HU is touching something and once the noise neteres the system it is amplified by the HU's internal amp and sent to your speakers.

Please ask your installer to do a clean install.

[low_bass_makker]

Originally Posted by DerAlte

To add fuel to the fire, is it "sssssssssssss", "khhshshshshshsshsh", "zzzzzzzzzzzzz", "chirrrrrrrrrr" or "cheeeeeeeeeeeen"?

Hmmm correct which type of noise is coming from the above as they will help us deduce the problem more clearly

[vishnuvijay]

hi lowbass, the noise i'm getting is the "it is like hiss speaker make when there is no audio playing and the volume is set to full."

there is no hiss when the volume is set to 0. the hissing increases with incease in volume. i can hear the hissing when there is a break or pause in a song ( like rock songs when there is a pause and then the guitar begins) and also when i pause the cd by pressing the pause button.

i tried with different cds(mp3 and audio). it is very disturbing. i had a honda city 1.3 in which i had the same head unit and speakers with oe honda wiring and in that car there was no such noise.

if i change the wiring, what type of cables should i use( specification or rating etc)?

my installer said that if there is short in wiring, the HU wouldn't play and that there is no short in the wiring.

[vishnuvijay]

Originally Posted by DerAlte

But that would cause the amp's overload circuit to act, no? Also this would be localized to THAT speaker whose cable is touching ground.


To add fuel to the fire, is it "sssssssssssss", "khhshshshshshsshsh", "zzzzzzzzzzzzz", "chirrrrrrrrrr" or "cheeeeeeeeeeeen"?

deralte, the sound is "sssssssssssss", "khhshshshshshsshsh", "zzzzzzzzzzzzz" and not chirrrr or cheeen. it is not audible when volume is 0. it increases with volume. if i turn the volume level to full maximum, then the sound is sssssssssssssssszzzzzzzzzzzzzz + chirrrrrrrrrrrrrrrrrrtrrrrrr.

should anything regarding the car battery connections be checked ?