Whining Noise

[jrdiesel]

Okay. Just going by what I was taught.

 

Thanks.

[tacomaboy]

Are the RCA's ran down the opposite side of the car to your power wire?

 

I hate to start an argument but I this is one of those things that really grinds my gears because people don't understand electricity. DC current does not produce a field of electromagnetic energy around the wire, so it is entirely moot to run power on a seperate side as the audio for purposes of eliminating radiated interference. The only reasons you should do that is if you just don't have enough room or you're anal retentive and want to keep it seperate. Whichever the case may be, it does not have any whining or otherwise effect on the audio.

 

[/soapbox]

 

Audio is not DC, it fluctuates with the sound just like AC but without a set 60Hz frequency.

 

Edit: Doh you are referring to the power wire being DC. I think th theory is, and I havent tested it, that the alternator provides the DC power, but it is not a strict constant voltage, and the change in voltage operates at a frequency (2000-7000 RPM) in the audible range. That change in voltage acts as AC and can be picked up by the RCAs.

[terron]

Are the RCA's ran down the opposite side of the car to your power wire?

 

I hate to start an argument but I this is one of those things that really grinds my gears because people don't understand electricity. DC current does not produce a field of electromagnetic energy around the wire, so it is entirely moot to run power on a seperate side as the audio for purposes of eliminating radiated interference. The only reasons you should do that is if you just don't have enough room or you're anal retentive and want to keep it seperate. Whichever the case may be, it does not have any whining or otherwise effect on the audio.

 

[/soapbox]

 

Audio is not DC, it fluctuates with the sound just like AC but without a set 60Hz frequency.

 

Edit: Doh you are referring to the power wire being DC. I think th theory is, and I havent tested it, that the alternator provides the DC power, but it is not a strict constant voltage, and the change in voltage operates at a frequency (2000-7000 RPM) in the audible range. That change in voltage acts as AC and can be picked up by the RCAs.

 

The whine was explained to me by an EE that typically the amps and headunits arent grounded properly and the power that would usually exit out the ground to the chassis to find its way back to the battery finds its way into the audio cables because there is no isolation or conditioning of RCA output. The problem appears only when the car is running because the absolute ground (the alternator) is now driving more current through the system. Yeah, it kind of went over my head too.

 

Its also a good point that the alternators voltage fluctuates even if only a tiny bit with engine speed.

 

To derail from the thread further; I didn't run into this problem in my 08 Altima.. I just made sure everything was grounded well and ran the HU its own +12v from the trunk dist block where my amps get their power. It was more work but I didn't like the puny wire that Nissan had in the vehicles stock harnass.

[S_Chiem424]

So I can't figure out the problem... I'll live with it. I kind of like the "supercharger" whine anyhow.

[jrdiesel]

So I can't figure out the problem... I'll live with it. I kind of like the "supercharger" whine anyhow.

 

 

Problem solved then.

[S_Chiem424]

Spent 3 hours experimenting.... I got sick of it. My friend asked if I had a supercharger or something. I told him, "No, I just have bad grounds". Hahaha.