Audio & Power in car: Electrical Noise - Mogul, XV6800 Accessories

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...

Related

Docking Station

I have the HTC dock for the ameo arriving monday / tuesday. I lll post pictures and comments for all that are interested.
Ordered from expansys £69
ade0282 said:
I have the HTC dock for the ameo arriving monday / tuesday. I lll post pictures and comments for all that are interested.
Ordered from expansys £69 with a second battery
Click to expand...
Click to collapse
Have you noticed this ?
http://www.gpsforless.co.uk/product_details.php?id=9256
GPSLessforLess cradle
Palmchen said:
Have you noticed this ?
http://www.gpsforless.co.uk/product_details.php?id=9256
Click to expand...
Click to collapse
That seems to be a charging and syncing station, rather than a full docking station (with its USB passthrough ports etc). Having said that, if it charges from the mains while connected with PC, as description implies, it will be exactly what I'm after. Not a bad price either. If it's the same one I saw a few weeks ago, the price has halved since then. Hmmm, might get two (home and work)...
EDIT:
No, the one I saw before was this:
http://www.gpsforless.co.uk/product_details.php?id=7558
With second battery slot. Doesn't seem to be available though. The other probably replaced it.
What is the function of earphone jack holes of station?
On the left side of Athena, there are three jack holes, i.e., earphone, miniusb, and vga out. However, the docking station only plugs into miniusb and vga out. It does not plug into earphone. However, there is a earphone jackhole on the right side of the docking station, but when I plug into that earphone jack hole, I did not get any sound from it. I can not use the original earphone jack hole either, because it was blocked when you set Athena into the docking station. I have a question that What is the function of earphone jack holes on the docking station if no sound coming out from it?
The audio output is also available from the mini USB connection on the Ameo, connection of a correctly wired addapter to the Ameo will mute the onboard speakers thus routing the audio to the addapter cable/ port etc. Either your unit is faulty or the dock unit is incorrectly wired -
When you dock the device try playing some music etc. on the unit and does it emmit any sound from its onboard speakers ? - Mike
I *DID* get two of the cheaper cradles for my Advantage. They plug into the mains with a supplied adapter (5V 1A) and the PC's USB.
The trouble is, the charging time seems to be as if it were charging from USB only - ie sloooow. This is despite the power light coming on when mains is connected (or when USB is connected). Does the USB charging override the mains charging? I've tried disabling the USB charging with a registry addition as described elsewhere, to no effect.
If I unplug the adapter the LED on the adapter remains lit for a very long time - several minutes at least. Even unplugging the USB and the adapter at the same time doesn't affect that - the LED on the adapter itself and the cradle remain lit, but the charging light on the Advantage goes out. Very peculiar.
For someone with a full docking station - how quickly does it charge? If it's at full mains speed I may upgrade to one or two of them (when finances permit) for syncing, and use these cheap ones as mere mains-only charging stations dotted around the house.
panvita said:
On the left side of Athena, there are three jack holes, i.e., earphone, miniusb, and vga out. However, the docking station only plugs into miniusb and vga out. It does not plug into earphone.
Click to expand...
Click to collapse
The Athena mini-USB also provides Audio-out like all other new HTC devices. This would explain why the dock only connects to the mini-USB jack. However then, you should get some audio noise out of the dock's jack... this seems not to work...

The i.Trek Powered Cradle Mount with Powered Speaker

I recently purchased the i.Trek Powered Cradle Mount with Powered Speaker from Semsons (http://www.semsons.com/ipocrmowiins18.html). It arrived today and I wanted to jot down my first impressions. By the way, My Sprint Mogul is running the leaked 3.16 ROM and radio. So, I use the internal GPS for navigation. I bought the cradle/mount so that I could use my Mogul like a TomTom / Garmin / etc.
I purchased the cradle with the standard mounting kit and the RJ-11 to 4mm DC cable. It also came with a car adapter. The standard mounting kit includes 1 windshield mount (suction cup and flexible arm), 1 adhesive disc, and 1 vent clip adapter.
The windshield mounting arm seems very stiff and stable. I could not get the suction cup to disconnect from the window without flipping the release switch. I have not tried the vent clip, but it seems like it would attach to most vent configurations as the clips can attach to vertical or horizontal vents.
I was disappointed to see that the car adapter is not a mini-usb connection. You have to plug the car adapter into the cradle and dock the Mogul in the cradle to charge it. On that note, there is a switch on the side of the cradle that turns the charger on and off so that if the Mogul is fully charged, you can still use the speaker without sending power to the mogul's charging port.
The speaker on the cradle seems plenty loud. Unfortunately, there isn't a hardware volume adjustment for the built-in speaker. If you are driving a loud vehicle, you may have a little trouble hearing the speaker, but in my Buick sedan, I had no problems.
The dock has an RJ-11 port that you can use the included cable with to charge a GPS adapter. It also has an audio-in connection, however, the cradle does not come with a cable or microphone for audio-in. I believe this is a serious omission on i.Trek's part.
When docked, my Mogul played all of its audio through the cradle's speaker. As I said before, the volume was very adequate. However, I could not give any voice commands to MS Voice Command and callers could not hear me. I turned on Bluetooth and used my Jaw Bone headset and got the same results. Audio would come through the headset momentarily, switch back to the speaker on the cradle, and the caller could not hear me.
For some reason, plugging the Mogul into the cradle disables all microphones. I can only assume this is because the phone expects something to be plugged into the audio-in port on the cradle. This may become a serious problem for me as I take a lot of calls from the car. I have to undock the phone from the cradle to make or take a phone call. This is annoying, to say the least.
If anyone knows of a registry hack that will play audio through the speaker, but keep my Bluetooth headset active, please post it here or PM me. I would be very grateful.
I have taken some pictures of the dock and will post them soon. I hope this helps you make a decision about your purchase.
Sorry about the poor quality pics. I took them with my phone (kind of ironic, eh?).
so it does have an audio out and audio in. hmmm. i think you can get the clip on mic from seido for about 12 bucks. i may have to order this and an adaptor (stupid aftermarket proprietary plug required) for my radio and give it a shot.
all in all an external mic may be easier than using bluetooth and cause less of a problem <shrug>.
good luck and thanks for the pics.
Is that RJ11 to dc to power the cradle from a phone jack so you could use it as a charger in say a hotel room?
mogul67 said:
Is that RJ11 to dc to power the cradle from a phone jack so you could use it as a charger in say a hotel room?
Click to expand...
Click to collapse
No, they use the RJ-11 cable to charge a stand-alone GPS receiver. It has nothing to do with a land-line telephone.
This thing is a piece of crap.
It takes two hands to get the phone in or out. The sound from the audio output is horrible.
Save your money.
rangie said:
This thing is a piece of crap.
It takes two hands to get the phone in or out. The sound from the audio output is horrible.
Save your money.
Click to expand...
Click to collapse
Getting the phone into the cradle is definitely a pain in the neck. If you don't get it lined up just right, it won't dock. You would think they could have fit it to the phone a little better.

Nexus 7 in car install Engine noise help??

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.

[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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