Nexus 7 in car install Engine noise help?? - Nexus 7 General

alot of engine noise and hissing noise even when car is off
its a nexus 7 timurs rom, sound going from nexus via 3.5 tapped into factory cd changer any suggestions?

Ground loop isolator.......

I just solved this problem in my own installation. After some searching around, I ended up deciding on this:
http://www.amazon.com/gp/product/B001EAQTRI/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1
It's a good price, free shipping with Amazon Prime and completely eliminates the alternator whine you're experiencing.

Thanks i ordered it from my experience in car audio ground loop isolator a while removingr whine also make the sound dull
Maybe i am wrong but it doesnt seem like a proper solution
Maybe grounding usb power? Or the 3.5 mm jack on the nexus to the cars body?

Who said you had to use one in the audio line?
If you know what to look for you can isolate the noise in the power supply line itself.Something like this. Now the real question is why is it hissing even with the vehicle off. In reality it shouldn't do it at all but nothing is ever perfect and trying to track down a ground issue can be more trouble then it's worth. Do you have battery drain issues? or low charge or possibly high charge while driving? Wondering if you have a possible problem with the voltage regulator in the car itself. When they go back they can actually cause a draw with the vehicle off. Doubt that is the issue but figured I would ask.
And just to be clear as to what you are doing. You are going from the Nexus (headphone jack) to the front of the stock car stereo(AUX input 3.5 jack). Do you have the tablet plugged in to a cigarette adapter or charging by any means via the car? If so, have you tried having it not plugged into the charger to see if that changes anything? Most cigarette or power adapters are not isolated so if you use them you have the possibility of it happening.

Related

Audio & Power in car: Electrical Noise

I've got a problem when I plug my phone into my car stereo as well as cigarette adapter.
I'm also got a kind of custom setup.
Audio
Honda Civic Stock Stereo -> CD Changer to Aux Input Adapter -> 3.5mm to 2.5mm adapter -> 2.5mm input on HTC Y adapter.
Power
Belkin Cig. Lighter to USB Female Port (From old iPaq) -> HTC Stock Sync/Charge USB cable -> MiniUSB input on HTC Y adapter.
So, when both the power and audio are plugged in, I hear a horrible hiss on my car stereo, not to mention a sound that varies in pitch to my throttle. When I unplug the power, the audio is completely clean. To me this seems like some kind of a grounding issue - to say that the Audio and Power both have seperate grounds, and bridging the two creates a potential difference in the form of noise on my Sound. Also to note: I only hear the noise when the Y adapter is plugged into the phone. With the audio and power plugged into the Y adapter, but the Y adapter not plugged into the phone, It's perfectly clean. I'm kind of baffeled.
The only solution I can think of is to gut the Belkin Power->USB adapter, and providing it from 12VDC elsewhere. I've got a tap directly below my passenger seat where I have a big power inverter tied to my battery. I don't know if I'd hear the same sound by grabbing my power from there.
Anyone with an engineering mindset have an idea? I'm open to suggestions.
If it was a grounding issue I would expect a buzz not a hiss...
Does it go away when you unplug the power and just leave the audio?
Go away or stay when the phone is unplugged?
It could be a bad adapter so maybe try another...
It goes away when I unplug the power, or unplug the phone. It's only present with audio+power both plugged into the phone.
I've tried powering it using the AC adapter and a power inverter - that sounds clean.
Fix?
I have the same problem and went out and bought a ground loop isolator from Radio Shack. It ran about 12.00 and it definitely got rid of the noise but unfortunately it noticeably affected the sound quality of my music and made it sound high pitched.
Perhaps buying a higher quality one will solve the problem. In the meantime, I've returned the isolator and just run on battery when listening to music. Perhaps I'll hit Ebay and see if there's a higher quality ground loop isolator.
Definitely a ground loop problem.
As devoe said, you can get a ground isolator and put in the audio line, but those are typically a simple transformer, and they often don't pass low frequencies very well.
You may be able to simply cut the ground going to the audio jack input. Not a perfect solution, but it sometimes works. But it usually requires a blocking cap in each channel. An experiment for sure.
A different power adapter might help. Or not.
You may also be able to add in a power plug that is wired directly to the radios ground and power. Then your power adapter plugged into that might have a ground that is close enough to the radio ground to not have a problem.
Me, I would open up the power adapter, and if it is a switcher supply with a transformer, see if I could isolate the ground.
I had the exact same issue. I believe it is called alternator noise.
01 Nissan Maxima with Eclipse AVN 5435 RCA hook up. When cigarette lighter and audio are both on, it makes the noise. I dont think it happened in the beginning but definitely happens now....
Luckily my Kicker 12L7 overwhelms the noise and allows me to tolerate it...somewhat.
When the audio wire and power wire are close to each other, this problem happens. Intead of using an isolator for audio wire reducing quality, try shielding your power wire instead. Might work but not very sure..
worwig said:
Definitely a ground loop problem.
As devoe said, you can get a ground isolator and put in the audio line, but those are typically a simple transformer, and they often don't pass low frequencies very well.
You may be able to simply cut the ground going to the audio jack input. Not a perfect solution, but it sometimes works. But it usually requires a blocking cap in each channel. An experiment for sure.
A different power adapter might help. Or not.
You may also be able to add in a power plug that is wired directly to the radios ground and power. Then your power adapter plugged into that might have a ground that is close enough to the radio ground to not have a problem.
Me, I would open up the power adapter, and if it is a switcher supply with a transformer, see if I could isolate the ground.
Click to expand...
Click to collapse
What he said. The fact it alters in pitch with engine speed says it's alternator wine, which is related to grounding issues. I have a similar problem, but it's not a wine that follows RPMs, just a static like hiss. I need to dink around with the ground and see if I can get it.
I had a similar problem. I hadn't used my car audio for a while and when I started it up again, it was making horrible noises. I bought a new charger and had significant improvements. I'd recommend buying a charger from radio shack. If that doesn't fix it (or if you find it cheaper online), then you can return it.
If you can, verify the grounding cable on your cigarette lighter. Best thing you could do it to cut it and look for the nearest solid metal ground point in the lighter's general vicinity and ground it to that. Could be the stock ground on the plug.
I'm a car audio buff and my previous car, a 01' Camry had that issue when I charged my Creative Zen touch and played audio through it as well... Fixed it by re-grounding my lighter plug directly to the chassy, its just a matter of finding the right spot nearby to ground it with a good sized gauge wire, like 12 or 14 AWG.
I had a similar problem. I discovered that my problem was that the Mogul's CPU noise was conducting out the USB DC power cable and then coupling back through to my FM transmitter on it's DC power cable. I never was able to completely get ride of the noise. However, I was able to reduce it substantially by using a different USB 12VDC power source. USB hubs normally contain low pass filters on the USB power lines, so your mileage may vary.
The tick to solving your problem is to try different configurations by moving and disconnect wires. Often you can here noise variations that will indicate whether the noise is external to your system.
EMI is either conducted (ground loops) or radiated. Since audio is below 1MHz it is best if there is only a single ground point. Since you normally have multiple wires, ground loops are common, so keep your wires short and your devices close together.
Same trouble here, but on a Touch Pro...

Noisy Mains Charger

I noticed this morning a strange hissing noise which at first I thought was coming from the phone. This was when I was using the phone whilst it was plugged into the mains charger.
I removed the cable and the noise stopped. I plugged the phone into a USB port on my PC and there was no noise this time. So I checked the mains charger that came with the phone and sure enough the noise was coming from there!
It almost sounded like there was a fan inside, a very similar noise.
Has anyone else experienced this or can you recreate this?
It also happens to my charger, you can feel comfortable there are no problems
Sent from my Galaxy Nexus using xda premium
apprentice said:
I noticed this morning a strange hissing noise which at first I thought was coming from the phone. This was when I was using the phone whilst it was plugged into the mains charger.
I removed the cable and the noise stopped. I plugged the phone into a USB port on my PC and there was no noise this time. So I checked the mains charger that came with the phone and sure enough the noise was coming from there!
It almost sounded like there was a fan inside, a very similar noise.
Has anyone else experienced this or can you recreate this?
Click to expand...
Click to collapse
I do not have this charger but from your description it sounds like normal switcher noise.
The charger likely uses a switcher for dc-dc conversion. When not well designed they can have an audible noise. Usually it is not a fault and no reason to worry.
kuikkaj said:
I do not have this charger but from your description it sounds like normal switcher noise.
The charger likely uses a switcher for dc-dc conversion. When not well designed they can have an audible noise. Usually it is not a fault and no reason to worry.
Click to expand...
Click to collapse
Thanks for the info guys
i hoped i finally got rid of that noise with a new phone, but my note 2 charger makes noise too.
just like my LG O2X charger and Galaxy Tab 2 7" charger.
yet all my other chargers are capable of being perfectly silent.
it's loud enough to give me trouble sleeping, and i'm used to sleeping next to a noisy PC.
I don't have a Galaxy Note 2 yet, but my original Galaxy Note's charger makes noise, as well. I believe because it has a high mAH recharging, because I use as an extra charger an old blackberry charger (with a long long cable xD) with only 500 mAH recharging power doesn't make any noise. I don't know if it has anything to do with how much voltage is flying through the charger has anything to do with it, but:
*Samsung chargers make noise.
*Other chargers I have don't.
All the chargers since the SII's have emitted some noise when there is no device plugged in. I don't really mind honestly.
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Check out my huge collection of 64GB Samsung Galaxy Note 2 Videos (Demos, Accessory Reviews)
Using nokia phones since 2002 i have to say most of them make that sound, dont worry
I got my SGNII at the weekend, and I have a very noisy charger, to the point where, as it is close to my bed, it wakes me up when its finished charging. However its only noisy once the phone is fully charged. Unplugging the phone once charged means the noise stops, but it also means my phone has been running on battery for 6 hours before I get up.
I think I will switch to a different USB charger that doesn't sound like a mouse being tortured
No Problem
Never faced this issue ever. Maybe faulty chargers i guess

[Q] Weird signal disturbance

Hi,
I noticed a weird problem in my HTC One ....While using my car charger and aux cable together, I noticed a weird signal disturbance in the speakers of the car whenever I made or answer a call(I was using the mic of the phone and the car speakers with the aux cable). The disturbance was something like the same disturbance that one gets in a landline when we keep the landline close to a mobile. When I removed the charger and used the aux cable only, the disturbance was gone so it's got definitely got to do something with the charger. Also, when talking from the mobile directly while using the charger, there is no disturbance. Is it something to do with the charger or my phone?
110 views and no reply? Someone please help
udit_narang said:
Hi,
I noticed a weird problem in my HTC One ....While using my car charger and aux cable together, I noticed a weird signal disturbance in the speakers of the car whenever I made or answer a call(I was using the mic of the phone and the car speakers with the aux cable). The disturbance was something like the same disturbance that one gets in a landline when we keep the landline close to a mobile. When I removed the charger and used the aux cable only, the disturbance was gone so it's got definitely got to do something with the charger. Also, when talking from the mobile directly while using the charger, there is no disturbance. Is it something to do with the charger or my phone?
Click to expand...
Click to collapse
Its maybe noise coming from your alternator to your charger. Your car alternator is AC current converted to DC trough a rectifier circuit. Even if its converted to DC, there is always a small quantum of residual AC in your car power system. That AC noise is then routed to the phone and then your audio system producing that audible noise from your speakers . Is that noise increasing in pitch with the acceleration (rev of your engine)? if yes, the best solution for this issue is to buy a noise filter.
If this is not that kind of noise (form alternator) its simply noise coming from your phone transceiver (like a pulsating noise). In that case you will need to have a very good aux cable (shielded) and all your car audio properly grounded and shielded.
udit_narang said:
110 views and no reply? Someone please help
Click to expand...
Click to collapse
You can't expect someone to reply to your every question. Just be patient

[Q] Audio EMI Noise in Car - Should I return?

Coming from a developer edition M8 that I converted to Gpe....I purchased the 64 GB Nexus 6 from the Google Play store last week. Everything works great....except I hear a lot of EMI/Power noise when connected with a 3.5mm aux into my car stereo while the charger is plugged in. It is especially prevalent during any screen activity. The M8 had no such issue. I've taken the following troubleshooting steps:
1. Replaced the aux cable with a better shielded one.
2. Tried the supplied quick charge adapter and cable (my car has a power inverter built in).
3. Plugged the M8 back in with the above and didn't get any EMI.
The noise is present whether I am streaming from Spotify, Google Play, or playing Non-Streaming local media.
Has anyone experienced this kind of issue? Should I get an RMA from Google?
I love the phone so far....
I doubt you'll get any satisfaction from an RMA. My experience is that car radios are EMI nightmares, in that it really doesn't take much to trigger it.
You say that this is with the phone plugged in to power? As in, it is *NOT* present when it is running on battery? Car electrical systems are *incredibly* noisy. With a high voltage spark ignition system, it is no wonder at all!
In fact, for car audio enthusiasts, there are lots of special devices out there for handling this kind of noise, especially when dealing with amplifiers (which amplify the noise as much as the music!).
http://www.ebay.com/bhp/audio-noise-filter
Note that there are filters that clean the AUDIO line, and also filters that clean the POWER INPUT line.
*** This EMI noise does NOT indicate that there is a fault in your phone!
doitright said:
You say that this is with the phone plugged in to power? As in, it is *NOT* present when it is running on battery? Car electrical systems are *incredibly* noisy. With a high voltage spark ignition system, it is no wonder at all!
*** This EMI noise does NOT indicate that there is a fault in your phone!
Click to expand...
Click to collapse
Yes....if I remove the power cord, the EMI goes away. Perhaps the Nexus 6 is just more susceptible to this kind of interference.
skylaneffz said:
Yes....if I remove the power cord, the EMI goes away. Perhaps the Nexus 6 is just more susceptible to this kind of interference.
Click to expand...
Click to collapse
That's... pretty much what I said. I also explained why, and what you can do to deal with it, i.e. by installing filters.
Didn't read your post thoroughly, but you might have some ground loop problems. This happens whenever I have anything feeding audio into the aux line in my car that is also powered by one of my car's power ports. Try a ground loop isolator from Amazon and see if it solves it: http://www.amazon.com/PAC-SNI-1-3-5-3-5-mm-Isolator/dp/B001EAQTRI/ref=sr_1_1?ie=UTF8&qid=1434054047&sr=8-1&keywords=feedback+isolator

Noise --- Nexus 7 conected by DAC to the amp on my car --- solution??

Hi.
I am finishing installation on my Nexus 7 in my car. I use the DAC Behringer UCA202.
There is a constant and strong noise... I was reading that it can be by charging tablet...
Please, anyone can help me?
Thanks
I was reading about this. It seems problem about ground while the tablet is charging.
Some solutions...
USB filter
RCA filter both, seems that there is a loss of quality of sound.
and any other?
Experiences???
Hi, it's a ground loop issue , i've installed my nexus 7 in my car, i removed the battery from it and use the 12v plug with a 12v to 3.7v converter, to get ride of the hum noise, i had to diy a ground loop isolator for the audio jack (but you can buy them on the internet), the hum/buzz sound is now gone.
The quality is good but the real issue is that i lost some of the bass, i don't remember clearly how much, i should try without it tomorrow to compare again, but i still enjoy my music .
The other possibility is to use à dc-dc isolator supply, but they are expensive (+100$)...
Hi, ground loops car caused by different potentials because of ground points that aren't the same and current flow that is picked up as noise.
My suggestion would be try an isolated 12V - 5V power supply. Those shouldn't be expensive and you can likely find some on eBay. There's a very high chance that will resolve it permanently.
Just needs to be capable of the current draw for the tablet in use & charging. If you're also using a hub and so on you could add second power supply as well.
i toyed around with passive usb isolators off ebay. cant tell if sq is any worse other than the immediately lowered noise floor with the hum gone.
As Marty mentioned, the problem is that there is a voltage potential difference between the amp's ground and the ground you are using with the power to your tablet. The passive power isolator/filter is easy solution if it works well enough for you. It won't deteriorate your sound quality, except that it may not fully eliminate the noise. A filter in the audio cable can cancel the noise, but it will also cancel certain frequencies in your music and affect sound quality. The "most effective" solution is to physically connect the amp ground to the ground you are using with the power to your tablet. That requires getting under the dash, finding the ground wires in question, and jumpering them. Or something similar. Hope that makes sense. But if a passive usb power isolator does the trick for you, then that's the "easiest effective" solution.
There are line-level (RCA) ground loop isolators that have excellent sound response, but they're not the cheap ones you'll find in a stereo shop or electronics store. They're $50-$100 but you can find them on eBay at times.
Jensen and I think 1-2 companies make some with great fidelity. But if the USB isolator did the trick, that's excellent. The ground is the problem, after all.
yeoldeusrename said:
The "most effective" solution is to physically connect the amp ground to the ground you are using with the power to your tablet. That requires getting under the dash, finding the ground wires in question, and jumpering them. Or something similar.
Click to expand...
Click to collapse
I did this, bridged the tablet ground and headunit ground together. It reduced the hiss, but it’s still noticeable especially when the engine speed is high.
I guess the next stage is to try an isolated power supply!

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