aeroplane sound

[kyheng]

Like ah, the problem you are facing is RCA cable or your earthing no good.. Or worst is your battery or alternator almost time.

 

[yewnen]

Hi Kyheng,

I've taken out my RCA cable, I found there's a kink at the cable, I was so happy because I thought the problem might because of the kink. So I've bought a new RCA cable (5M) and replaced the existing RCA cable. After that, I tested again. Found the aeroplane sound decreases abit, so I relocate the RCA cable again to other place the try. I've done so many round, but the aeroplane sound is still there but only a little bit. But I still feel annoyed because of the sound. Felt abit helpless now. Sigh!

I'll try to change my battery and try. Hopefully it can solve the problem. :)

Psst: By the way, how much will be an higher ampere rate alternator cost (for proton saga 4G15)? I think it's time to save some money on that. :)

 

[kyheng]

The alternator I also not sure, but last time when I change back original it cost me 150. But this part you have to wait till last resort, check the earthing first. This is the main cause, the battery and alternator should put to last for airplane troubleshooting..

 

[yewnen]

The alternator I also not sure, but last time when I change back original it cost me 150. But this part you have to wait till last resort, check the earthing first. This is the main cause, the battery and alternator should put to last for airplane troubleshooting..

Hi! No problem, I'll put both alternator and battery as last resort. I've read another thread on aeroplane sound. I saw there's one using the thin bare naked wire to wrap around HU's preout ground and connect to the HU Chasis ground. It's something mixing with the car battery negative terminal. Is it safe to do so?

 

[wyx]

generally, since i don't see your wiring connection for myself, it's safe to do so. In car electrical system, all sort of grounding will eventually connect to batt -ve, mostly through car chassis. If i were u, i will try the following:
1. Since u oledi found that the sound disappeared when RCA at HU are removed, then it's high chances that the HU grounding could b the culprit. Use multimeter to chk the Pre-out and HU chassis against car chassis.
2. if no multimeter, get a long insulated wires, connect it frm batt -ve to HU metal chassis (for troubleshooting, so juz run the wire directly frm batt to HU through bonnet n front door). Then see if any more sound?
3. if u hv portable player, such as discman, connect 1-to-2 stereo-RCA cable frm discman to amp, to isolate if it's amp/RCA cables/HU/Batt pblm.
4. Very important, make sure no power supply cable running along with the RCA. Becoz RCA carry low level signal that can b easily interfered by power supply line.
5. Sometimes, if RCA are in contact with any part that's vibrating, it will pick up noise.
6. You may also try parallel a 2200uF capacitor across HU +ve and -ve power supply. This will help draining off the +ve power supply high freq noise, if it exists, to ground(this refers to -ve of power supply). But make sure u get at least 16V rating capacitor, because your HU is running at 12~14V from batt.

Hope the above helps to solve ur pblm b4 CNY :)

 

[yewnen]

generally, since i don't see your wiring connection for myself, it's safe to do so. In car electrical system, all sort of grounding will eventually connect to batt -ve, mostly through car chassis. If i were u, i will try the following:
1. Since u oledi found that the sound disappeared when RCA at HU are removed, then it's high chances that the HU grounding could b the culprit. Use multimeter to chk the Pre-out and HU chassis against car chassis.
2. if no multimeter, get a long insulated wires, connect it frm batt -ve to HU metal chassis (for troubleshooting, so juz run the wire directly frm batt to HU through bonnet n front door). Then see if any more sound?
3. if u hv portable player, such as discman, connect 1-to-2 stereo-RCA cable frm discman to amp, to isolate if it's amp/RCA cables/HU/Batt pblm.
4. Very important, make sure no power supply cable running along with the RCA. Becoz RCA carry low level signal that can b easily interfered by power supply line.
5. Sometimes, if RCA are in contact with any part that's vibrating, it will pick up noise.
6. You may also try parallel a 2200uF capacitor across HU +ve and -ve power supply. This will help draining off the +ve power supply high freq noise, if it exists, to ground(this refers to -ve of power supply). But make sure u get at least 16V rating capacitor, because your HU is running at 12~14V from batt.

Hope the above helps to solve ur pblm b4 CNY :)

Thanks a lot for your advice. I'll try this after chinese new year.

Below are the information that I can feedback to your steps above.
1) I used multimeter to check for continuity of pre-out ground and HU chassis. I found there is not continuity between both points.
2) I have multimeter, so I skipped your step 2. :emoticon_U:
3) I don't have these items. But I'll borrow it from my friend. Thanks! After that I'll try.
4) My power supply line is laided in driver seat side, while my audio cables are at left side.
5) My RCA cables are tied firmly. Hardly shake. ;)
6) I connected a 82000uF capacitor (bought from cbkhoon) between +ve and -ve of HU.

I'll try on the items that I haven't done. But only do it after chinese new year. Thanks a lot!

 

[wyx]

1) I used multimeter to check for continuity of pre-out ground and HU chassis. I found there is not continuity between both points.
# try short preout gnd to chassis gnd. Won't harm your HU.

6) I connected a 82000uF capacitor (bought from cbkhoon) between +ve and -ve of HU.
# remove the cap(or disconnect one of the leg frm HU power supply), to confirm not cap leakage. Be careful not to short cap legs to any metal bcoz the charges stored take time to discharge.
[/QUOTE]

 

[sotplugDESIGNER]

erm i got that aeroplane sounds too,but my case is,sometimes got sometimes dunhav...sometimes if i run over a hole on road and the car shack then the sound will go off/on until i run on another hole n the car shack again,how come?

 

[wyx]

most likely is loose grounding contact. Intermittent problem is harder to isolate bcoz we can't juz measure with multimeter. For me, I will put jumper wire from solid ground to amp_chassis/HU_chassis/E'lizer_chassis/etc, one at a time, drive for few days to find the loose/poor contact. If nothing found, then use any cheapo RCA to replace the current ones, and drive for days again. Of course, if u have soldering iron, do some re-soldering and maintenance works (such as cleaning, coating, etc) on the existing RCA, especially those ground and shielding braid contact at RCA. This will cut down time taken for trial n error in isolating RCA.
Lastly, u want fast solution n no concern with $$, then ICE installer may b able to help...at certain cost.

 

[Zenn]

yes sounds like loose RCA or bad RCA input jack or maybe the RCA cable itself.

 

[sotplugDESIGNER]

thanks alot bro,i'll try try

 

[kyheng]

I tried to change my amp from 2 channel to 4 channel yesterday. Because the new amp is higher than old one and the connection points is not the same, end some short circuit on the HU. After I connected back all and test with the engine running, the airplane sound take over my speaker sound, end up have to go to a shop to check the problem. After a short while they know the problem, is from the RCA output from HU. So they put another earthing from the RCA jack to HU and the problem solved. Somemore is better than last time. Last time got some sound, now totally don't have. Futher the RCA cables and the power cable all lay together.

 

[wyx]

all low level signal must not be layout together with power supply lines. This is one of the root cause of noise encountered by many bros.
what do u mean by "end some short circuit on HU"? ...just curious abt the wiring :)

 

[kyheng]

Before the short circuit the HU has no problem with the sound, after that it comes out very loud. After some troubleshooting found that RCA jack from HU is causing the problem. After add another earth for it, all the problem solve, then lay the cables together also no problem. Anyway this problem will come out if we are using high power system, mine is around 500w rms only, so it won't affect much on overall. Another thing is maybe they are using cheap or low quality cables.