[PhilP69]

I've been using the PAC unit for a few months now and I notice that there is a considerable amount of electrical whining noise when the volume is up, but the source audio has a quiet part. I have an MP3 player and XM connected to the PAC, and they all share the same source of power (from the back of the stock radio). I also get sound bleeding through from AUX 1 to AUX 2.

Is anyone else experiencing this? Any thoughts?

Thanks,
Phil

 

[johnmax]

Cant say with the FX piece, but we use other PAC interfaces for GM and others and I have seen similar problems, especially with higher volume levels. Not a perfect product yet I guess.

 

[ShadyJC]

I've been using the PAC unit for a few months now and I notice that there is a considerable amount of electrical whining noise when the volume is up, but the source audio has a quiet part. I have an MP3 player and XM connected to the PAC, and they all share the same source of power (from the back of the stock radio). I also get sound bleeding through from AUX 1 to AUX 2.

The electrical whining noise sounds like a bad ground to me. Do you get whining on both Aux1 and Aux2? Does the whining get more high pitched when you step on the gas?

As for bleeding, it may be the RCA cables you are using, if you are running them in tandem through the car and they are not properly shielded I think it is quite possible you'd see symptoms like that... actually this could be the cause for your #1 problem too.

 

[PhilP69]

The electrical whining noise sounds like a bad ground to me. Do you get whining on both Aux1 and Aux2? Does the whining get more high pitched when you step on the gas?

As for bleeding, it may be the RCA cables you are using, if you are running them in tandem through the car and they are not properly shielded I think it is quite possible you'd see symptoms like that... actually this could be the cause for your #1 problem too.

I'm pretty sure it's not the power/ground source, because before I started using the PAC, I had my MP3 player on the same power source and piped directly into the DVD player and it was fine. I'm using Phoenix Gold double shielded cables for both devices.

The noise changes pitch based on engine RPM, so it's most likely coming from the ignition or alternator. I guess the PAC doesn't have very good power supply filtering. The next step is to add a noise filter. Maybe I'll shoot PAC and email to see what they say...

Phil

 

[PhilP69]

Cant say with the FX piece, but we use other PAC interfaces for GM and others and I have seen similar problems, especially with higher volume levels. Not a perfect product yet I guess.

Thanks for the feedback John. I'll see what PAC has to say.

Phil

 

[ShadyJC]

The noise changes pitch based on engine RPM, so it's most likely coming from the ignition or alternator. I guess the PAC doesn't have very good power supply filtering. The next step is to add a noise filter. Maybe I'll shoot PAC and email to see what they say...

Yeah, as you describe it sounds like alternator to me... let me know what PAC says (and what version of the thing do you have, when in SAT mode hit the Audio knob, it should give you some type of version information) since I have the same device and am not experiencing the same problem.

 

[ShadyJC]

PhilP69 - funny this came up again today, I was reading something over on a Lexus forum and someone mentioned they had very good success eliminating alternator noise with this product.

http://www.myradiostore.us/auxadapters/ ... ofiei.html

 

[PhilP69]

PhilP69 - funny this came up again today, I was reading something over on a Lexus forum and someone mentioned they had very good success eliminating alternator noise with this product.

http://www.myradiostore.us/auxadapters/ ... ofiei.html

Thanks for the idea - I might have a line level isolator sitting around somewhere - have to try it out.

Phil

 

[terps4]

Go to Radio Shack and pick up a Ground Loop Isolator. Just plug it up between your source and the car. It doesn't require any power. I used one to kill both alternator whine and the ground loop noise I was getting while my iPod was charging from the 12V plug. It worked perfectly. BTW, my iPod is hooked up to the DVD inputs through one of these things.

http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=270-054

-Andy

 

[benjr]

PAC makes a low quality adapter check out zappco amps and balanced line transmitters

 

[FXrod]

I'm also getting signal bleed with my PAC also. Using Monster MPC MCON-2M connects. Called PAC and they said I shoudn't be getting any signal bleed. I have a XM Roady II on Aux 1 and a Zen Micro on Aux 2. I'm not gonna hassle with taking it apart to swap it with another that might do the same. I just have to turn off the unused device and it works ok. Anybody else with 2 devices connected please check and post if you have same. Thanks

 

[terps4]

I recently changed to the PAC AAI-NIS box instead of going through my DVD AUX-input. The only noise I get now is from my Nextel cellphone. They are notorious for putting noise onto any circuit they come near. I only get it when I store the phone in the ashtray.

One thing though: I had to use my Radioshack Group Loop Isolator on this install. In fact, it is the only thing between my iPod and the PAC. When I tried my iPod on the PAC without it, I got a whole bunch of nasty alternator whine.

 

[ariza]

you are getting the whining sound because you have an audio cable to close to a power cable. make sure the audio cables (RCAs) are not touching or close to any of the power cables going to the PAC unit or the cars power outlets or cigarette lighter.

Your alternator and PAC unit are fine, anytime you have an audio cable that comes close to a power cable you get bleed from the vehicles power system and you can actually hear the alternator wind up through the audio system.

just go through your wiring and make it nice and neat with some zip ties, out of the way of other wiring.
this will take care of your problem. no need for a ground loop isolator.

 

[FX914]

Ugh! I got the PAC periph. installed and yes I have excellent sound quality from my Audiocrap DVD player vs. the FM channel, but I get that **** whining!

The techs put in the noise filter but that didn't help, and they checked the grounding.

Anyone know what else I can do?

 

[ariza]

Ugh! I got the PAC periph. installed and yes I have excellent sound quality from my Audiocrap DVD player vs. the FM channel, but I get that **** whining!

The techs put in the noise filter but that didn't help, and they checked the grounding.

Anyone know what else I can do?

I would double check to make sure that none of the audio cables are running near the power cables. Even an RCA cable running too close to a one of the aux outlets will give you the whine.

Also, check that the power and audio cables running out of the PAC and into the back of the head unit are not running near each other.

The whine you hear is not a problem with the PAC unit, this happens to a lot of audio equipment that is added to vehicles, amps, aftermarket head units, cd changers etc.

that’s why good installers will run audio cables RCAs down one side of a car and power cables down the other side when installing amps.

 

[FX914]

I went back after the install and they checked the grounding all over. I know these people, they do good work.
I dunno, now it pisses me off. All this because the INFINITI dealer put in that ghetto-ass DVD unit! (Remember my thread back in Jan?)

I'm at work now but I am going to check the audio configuration (on the DVD itself, I believe I have it set for surround sound) when I get beck to my car just to make sure everything is kosher.

 

[johnmax]

Well after checking the ground situation, there are some things to try. First, find where the noise is actually coming from. Disconnect the audio RCA cables from the PAC unit. Do you still have noise? If yes, then the PAC piece is bad. If no then reconnect the RCAs but disconnect them from the DVD. If you have noise now, scrap those cables and get a good set (Stinger, etc.). If no noise still, plug in the DVD. If then you still have noise then:
1- You have a bad DVD player (noise is somewhat typical for an Audiovox DVD, but not hard to get rid of)
2- Ground your DVD to the radio.
3- Add a GOOD RCA noise filter (PAC SNI-1). Did they try a good one?
4- Get power for the DVD at the radio harness. In my FX i got power for my Nav-TV at the lighter socket in the console at first, but it was a little noisy.
5- Did the installer cut the power line filter off of the DVD's power harness? Sometimes i cut them off, but need to put them back in for noisy vehicles. You may need to add one.

Engine noise is sometimes a pain to get rid of. If none of this works, you may want to try another brand DVD player. I'm assuming they put in a DIN size unit? (AVD300, MVDVD4 or similar) The Audiovox is cheap, and usually good. But sometimes you get what you pay for. Many aftermarket DVD units are Din size and should fit in the same hole with no modification. Wiring is virtually the same, but you may need to splice on the new power plug. Hope this helps.

 

[FX914]

Super-Props to johnmax!

I took my FX to his shop and he checked it all out and now I have a crystal clear audio playing from Ghetto-aftermarket DVD!

Good Job!

:thumbright:

 

[johnmax]

<bows to the crowd>