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View Full Version : engine noise through speakers... help


R1C3RCKT
09-04-2009, 12:39 AM
thought you guys may have encountered the same problem at one point or another.

so i installed my stereo myself and it worked great for a couple weeks, until yesterday when i started hearing engine noise through my speakers... car is a 04 e46 coupe that came with the hk system. the factory speakers and amp were kept, the head unit was replaced with a pioneer deh-5000ub, separate amp was added for sub.

so i have the speaker outs connected to the adapter that attaches to the factory harness which go to the factory amp i assume. i am getting a buzzing sound that increases in speed as engine speed rises and when i'm cruising and put the clutch in and engine returns to idle, i get the constant buzzing. this is most apparent when i have the volume set at 1 and the buzzing sound disappears when i turn it down to 0. any thoughts?
thanks

nachos23
09-04-2009, 01:03 AM
bad ground. some units require "engine noise filter" to eliminate buzzing through speakers. Can pick one up @ most audio stores. Can't remember if it connects to power or ground lead, but will eliminate engine noise. I'd go over wiring to make sure all connections are good and solid and you haven't missed any grounding points.

R1C3RCKT
09-04-2009, 02:45 AM
thanks for the infor. i thought it was a bad connection of some sort. and this goes between deck and car right? anyone else know if its power or ground?

nachos23
09-04-2009, 11:36 AM
Almost always ground. If ti was the power lead, your deck would be going on and off constantly (you'd know it)..... Bad or missing ground will cause the problem. Was quite common on older cars with a lot of non-digital devices.... I would try running a good (not tiny) wire directly between your components (connect to chassis ground connector) and connect it to ground on each end. That should fix it. You have whats known as a ground loop......

tominizer
09-04-2009, 12:14 PM
Yup.

Or if you have a good ground, try moving it somewhere else. Try and ground it to the chassis of the vehicle through one of the existing bolts/nutz..................

R1C3RCKT
09-05-2009, 02:15 AM
mmk. i tried a different grounding point than the harness ground. i used the bolt/nut thats just above the gas pedal. i noticed that the buzzing is still present and coming mainly from the rear speakers. any more help or suggestions?

nachos23
09-05-2009, 12:34 PM
Did you hard wire your upgrades or use connectors? Can you "remove/disconnect" the devices individually to determine where the ground loop is? did you try to physically connect the devices (radio and amp) with a single common ground and run that wire to ground?

R1C3RCKT
09-05-2009, 01:32 PM
the only upgrade i made is an aftermarket deck and its speaker wires are hard wired to the adapter that connects to the factory harness.

my current ground points for my amp and cap are the battery and was wondering where i should ground the factory amp, where is the ground for the factory amp, i'm only getting buzzing through the factory amped rear speakers? i've played with the gains on the deck to no avail. i've disconnected the rca's to the amp that powers my sub and no difference. i read on e46fanatics that it may be a poorly grounded alternator? where/how would i improve the grounds for the anternator, just remove and wirebrush it and reconnect it?

thanks for all the help:)

R1C3RCKT
09-05-2009, 01:35 PM
forgive me for the newb question, but whats a ground loop?

slemmer
09-06-2009, 03:32 AM
Might want to also cosider resister spark plugs and heavier shielded spark plug wires. When you get the whining is it only on the AM band or any other input source?

R1C3RCKT
09-06-2009, 06:45 AM
it happens for every source not just AM. what i can't understand is why i used it for almost a month w/o the noise and suddenly the noise is present

nachos23
09-07-2009, 09:23 AM
a ground loop occurs when the ground levels of different devices are not properly grounded and they "float"... By floating, I mean that it actually has a voltage on the lines because of the bad/poor ground.... The ground line should (when properly connected) have 0 resistance when measured against chassis ground. A floating ground actually has a small voltage and when you connect multiple devices (all analog audio) and the negative lines are not grounded properly the grounds float @ different voltages and you get whats known as a ground loop. The best way to eliminate ground loops is to run a common ground wire between the chassis of all audio devices and connect one end of the wire to a solid chassis ground..... Check the ground connections of all connected audio equipment, you are likely to find a corroded wire somewhere attached to an audio device....

nachos23
09-07-2009, 09:27 AM
How did you connect the new unit? Did you splice into the original wiring (ie the original connectors are still in tact), or did you cut the existing connectors and wire it in that way? The ground loop can still ocurr of the internal grounding of one of the audio devices has been comprimised or broken...... Sometimes, you'll have to check the internal grounding on your equipment. The reason it worked for a month is because something has come loose..... internally or externally on the devices.

gruppusol
09-07-2009, 11:45 AM
I think the problem you're having is coming from the installation of your aftermarket amp. Although the battery for bimmers are conveniently located in the trunk, I don't believe that connecting the ground wire directly to the battery is common practice. The power wire can be as long as you need it to be, however, the ground must be as short as possible. Try to find a clean and bare part of the trunk to attach the ground wire. You may also consider sanding down the small area that you're going to attach the bolt for the ground wire.

The other source of engine whine coming through is when rca wires or speaker wires run parallel to the power wire or any other wire with alot of current. Make sure that you don't tie them together. If they are going to be in relative proximity to each other, they should run perpendicular to each other.

Sorry for the long post...
Leo

nachos23
09-07-2009, 03:00 PM
Good points Leo. I was referring in my post to connecting the amp ground to chassis ground as well. Didn't think about the parallel wires to the speakers.... but excellent point..... The AMP is drawing enough power to create the noise, but if it was routing related, why did it start up suddenly? Won't it have been an issue right from the beginning if routing was an issue?

gruppusol
09-07-2009, 04:07 PM
The only thing I could think of is possibly the install was a temporary one to begin with. When R1C3RCKT was satisfied with the results, he decided to tie the wires later making it neater. Obviously I'm only speculating. Also, if we can assume that he has a sub box, maybe with two 10's or a 12, then if the box is not tied down, it could cause any number of problems. I like booting around in my cars and I could imagine something coming loose. My point is that there may have been some change that has occurred and it has been overlooked. I've been through this kind of stuff many times. Leo

limousine
11-03-2009, 05:46 AM
I just recently installed my new subwoofer and amp and now I am getting the engine noise comeing through the speakers. it didnt happen with the last set-up I had in the car. I've electrical taped up all the ends of the leads and still it comes through. can anyone please tell me anymore ideas to get this annoying noise to stop! thanks.

R1C3RCKT
11-05-2009, 01:59 PM
hmmm. my sngine noise through the speakers still continues, so now i just have the music up loud enough so i don't notice it, but its annoying when you're trying to have a conversation with your passenger and just want a bit of music so it isn't too quiet. once i have my winter beater on the road i'll try and fix the problem. my setup in the trunk is currently a sealed 12 sitting on a winter floormat in the trunk so it doesn't slide around. the amp is ziptied to the side of the trunk with the battery. connected through a 1 farad capacitor. the rca cables are run through the dash to come out the side of the center console that is nearest to the passenger seat. it runs under the passenger seat and under the door trim behind the plastic piece near the seatbelt and under the back seat into the trunk.

the noise is only coming through the factory rear speakers. the tweeter and front speakers in the doors do not have the engine whine. could someone point me to where the factory amp ground is? i was thinking i should check for corrosion and i guess i should ground my aftermarket amp and capacitor there instead of the battery.

anymore insights would be much appreciated.
Fletcher

gruppusol
11-08-2009, 01:45 AM
Try connecting the amp without the capacitor and the ground wire onto a bare metal area in the trunk.

InFBMW
11-15-2009, 09:32 PM
It also might be a bad amp. Happened to me before.

InFBMW
11-15-2009, 09:36 PM
hmmm. my sngine noise through the speakers still continues, so now i just have the music up loud enough so i don't notice it, but its annoying when you're trying to have a conversation with your passenger and just want a bit of music so it isn't too quiet. once i have my winter beater on the road i'll try and fix the problem. my setup in the trunk is currently a sealed 12 sitting on a winter floormat in the trunk so it doesn't slide around. the amp is ziptied to the side of the trunk with the battery. connected through a 1 farad capacitor. the rca cables are run through the dash to come out the side of the center console that is nearest to the passenger seat. it runs under the passenger seat and under the door trim behind the plastic piece near the seatbelt and under the back seat into the trunk.

the noise is only coming through the factory rear speakers. the tweeter and front speakers in the doors do not have the engine whine. could someone point me to where the factory amp ground is? i was thinking i should check for corrosion and i guess i should ground my aftermarket amp and capacitor there instead of the battery.

anymore insights would be much appreciated.
Fletcher

Your AMP ground is on the battery ? Why ? Is it the shortest way to ground it ? Try another place. *th-up*