okay, i finally got my speakers working, which took forever since i ran into problem #545, and 544 problems before that one. but they all work now, except i am getting some electromagnetic throttle pick up from my speakers. I can't hear it when music is playing, but inbetween songs, or if I turn my speakers all the way down, i get this high pitch whining sound that changes pitch with my change in engine speed. does anyone know how to solve this? I made sure not to cross my power,ground,and remote wire with any of the signal or speaker wires. At the closest point my left speaker wires may be about 3 inches from the power cable. please help.

i had a similar problem on a friends ranger install i did, turned out the ground wasnt doing to well with his paint on the place we grounded... try a different ground .. hope that helps

What are you running? Aftermarket HU? regular speakers or seperates? amplifier? Are the speakers screwed directly into the metal of the door or are you using plastic baffels? Is it all the speakers or just specific ones? Does the problem go away if you adjust the gain on your amp?

wow, you want some detail huh. well here's what I can answer. Clarion DXZ555MP headunit. From there the signal goes to a polk Audio c400.4 amp via shielded Monster cables. The amp is powering polk MM6 components. the mids are screwed into a wood spacer, while the tweeters are screwed into the stock tweeter bracket, which is then screwed into the stock door location with a layer of dynamat inbetween. I haven't tried adjusting gain, and I haven't noticed if it is all of the speakers, but hopefully what info I gave you will help.

Try lowering the gain in your amp. It will help with the engine whine and all you have to do is raise the volume a little to compensate.

As they say the devil is in the details.

Ok, first try turning off the amp and listening at the speakers. If you still hear the sound then the problem is either in the wires going to the speakers, possibly one of the wires it grounding to the chassis. It will usually happen due to chafing when the wire was run. Check any place the wire passes through a hole and start adding grommets. If it goes away check the amp ground and mounting screws. Even if it is mounted to wood those screws that were just a little too long may be a problem.

On the amp side, cap the amp inputs at the head unit. If you still have the noise try replacing or rerouting the patch cables.

If rerouting or replacing the cables doesn't get it check you HU. Remove it from the dash and listen. No noise means something under the dash is putting out extra EMI. You can try adding some copper tape behind the radio. This is normally only necessary if you are running a high output alternator or ignition system. Check your antenna input to the stereo and make sure it is plugged in all the way.

Another common cause for "alternator whine" is not having your amp and signal source (HU) powered and grounded at the same place. Using the OEM wiring harness to power the HU is convenient, but means the HU and amp are getting power and ground from different locations, increasing chances of a ground loop.

double check all grounds. it most likely will be the ground for the amp.
if that doesn't solve it . . . how did you run your wires? did you run new speaker wires? if so are they run parallel to the power wire for the amp? that will cause a problem. sam question for the RCA wires.

and a cheap way to help fix engine wine. pick up a ground loop isolator and plug that into the rca's you ran and then into the amp. 9 times out of 10 that will clear the problem up, or at least make it a lot better

As they say the devil is in the details.

Ok, first try turning off the amp and listening at the speakers. If you still hear the sound then the problem is either in the wires going to the speakers, possibly one of the wires it grounding to the chassis. It will usually happen due to chafing when the wire was run. Check any place the wire passes through a hole and start adding grommets. If it goes away check the amp ground and mounting screws. Even if it is mounted to wood those screws that were just a little too long may be a problem.

On the amp side, cap the amp inputs at the head unit. If you still have the noise try replacing or rerouting the patch cables.

If rerouting or replacing the cables doesn't get it check you HU. Remove it from the dash and listen. No noise means something under the dash is putting out extra EMI. You can try adding some copper tape behind the radio. This is normally only necessary if you are running a high output alternator or ignition system. Check your antenna input to the stereo and make sure it is plugged in all the way.

If I turn the amp off I will not get any power to the speakers at all? so i don't know how they would still whine, usless that's how the engine whine works. Im pretty sure no wires are grounding to the chassis because my amp would warn me of the short and shut down.

I did mount my amp directly into the floor of the car, so that is metal on metal, but there is carpet between them. Could that be causing the problem?

i'm pretty sure my ground is good. I have the amp located under the passenger seat, and the ground wire is only about 5 inches long and I used a grinder attachment with my dremel to sand the paint down to the metal for the ground.

as for the speaker wires, I was aware during the installation that you are supposed to keep any signal wire away from the power cable, so i did this the best I could but still could not avoid coming within a few inches on the driver side without having to route the speaker wire around the back of the driver seat.

had the same problem with my install in my truck. I'd focus on the headunit ground. It's VERY hard to pick up noise in speaker wiring due to the low impedance of speakers. The RCAs between the amp and the headunit are a bit more troublesome, due to the high input impedance of the amp, the size of noise vs. the size of the signal is a lot larger there.

But if the headunit is grounded through the body, and not grounded to the amp, then any noise that the body picks up between the headunit and the amp will show up in the audio signal.

The headunit output is single-ended, or is a voltage reference against the ground as the head-unit sees it. The amplifier looks at the voltage the same way. The ground line (shield of the rca connector) attempts to help with this, but it's not great at it.

The shielding on you monster cables, unless the cables are marked as being directional (shield pinned to - at one end only) is actually useless, and might be causing more problems.

What I'd do to test it all out is to pull the head unit, and then run some temporary wiring for power/ground from the amp to the head-unit. If that kills the noise, then your problem is in the grounding of the head-unit.

Car audio REALLY needs to get away from single-ended interconnects. High input impedance + low signal voltages + single-ended wiring + high noise floor = bad sound. A higher voltage, lower impedance, differential system would be MUCH better.

And I noticed when I did my truck that the stock Infinity system does most of that (12Vpeak-to-peak, fully differential).

thankyou for your very extensive and detailed responses, Hopefully this should be enough info to help me solve my problem. If i can't figure it out i'll get back to yall. but thanks again!

edit: quick question, when you say "ground the headunit to the amp", do you mean instead of using the stock head unit ground, run a ground cable to the same location as the amp ground?

edit: quick question, when you say "ground the headunit to the amp", do you mean instead of using the stock head unit ground, run a ground cable to the same location as the amp ground?

Bingo.

If I turn the amp off I will not get any power to the speakers at all? so i don't know how they would still whine, usless that's how the engine whine works. Im pretty sure no wires are grounding to the chassis because my amp would warn me of the short and shut down.

It shouldn't whine. If it does then you are having grounding problems with the speakers. This usually is caused by the speaker cause by some part of the speaker frame touching metal. Most likely this happens when the speaker is screwed directly into the metal of the door. As for the amp seeing this as a shor it depends on the map. Most amps protect against short by looking for current overload conditions kind of like the surge protecture you use on AC lines. This works great for DC protection but not so good for AC. The hum you are hearing is an AC signal with a current dray in the microamp range, well below anything the circuit is designed to protect against.

I did mount my amp directly into the floor of the car, so that is metal on metal, but there is carpet between them. Could that be causing the problem?

This is what I was looking for. It is generally a bad idea to mount the amp directly to the cars chassis. Those screws are creating additonal grounding points and allowing RF noise into your amp. Try this dismount the amp and put a piece of wood under it. If it is a gound loop issue this is a simple way of isolating the amp form the chassis.

Welcome to the wonderful world of mobile audio. If you want to better understand the though process behind some of the sugestions I sugest picking up a copy of Auto Audio by Andrew Yoder. http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=500-005 I picked it up back in 2000 and it is an excelent read for anyone wanting to get started in mobile audio. It is a big 300+ page book but it is written in plain engilsh so you don't have to be an EE to uncerstand it. It has saved me from pulling out my hair on a few occasions. Good Luck!

Car audio REALLY needs to get away from single-ended interconnects. High input impedance + low signal voltages + single-ended wiring + high noise floor = bad sound. A higher voltage, lower impedance, differential system would be MUCH better.

The sad part is they were out there but no one wanted to buy them. I used to have an Adcom amp that used mini XLR balanced inputs. The amp was a 2 piece afair with a underdash converter the connected to the HU and then a custom cable that went to the amp. I picked it up on trade for 3 Orion 225HCCAs (boy do I feel old that had to of been '90 or '91). The thing was great until someone flet the amp would look beter in their car. :mad: Sucked because without the converter it was totally useless.