posted
I rarely get engine whine in my own vehicles or friend's vehicles that I've installed in. In my ex-girlfriend's Cutlass and Taurus & in my girlfriend's Civic I get whine. With my ex-girlfriend's cars I cheated and used an LOC to go from the Kenwood h/u's speaker outs to to the RCAs. I do not want to half-ass things this time. The whine gets louder and pitch is raised as the RPMs goe up, and it gets louder when the gain is raised. This is what I am working with:
1999 Honda Civic EX
Knukonceptz 4 gauge power cable run on passenger side
Knukonceptz 4 gauge ground from negative terminal to chassis and from chassis to amp
Radio Shack RCAs (today swapped out for Scosche RCAs) run on driver side
Only thing I haven't tried is running power wires from HU directly to battery. I just tried different RCAs; I ran them outside of the car to see if noise was picked up by the current RCAs. As every thread about noise suggests I tried a new ground wire behind dash to the HU. I even tried connecting the ground wire from HU to amp's ground. Finally I tried grounding out RCAs. I tried to ground out just one of the RCAs and had no whine. Then I tried it on both RCAs and the whine came back. When going back to just one RCA and there was still noise.
Voltage at the amp is 12.27 volts. I get the same reading at the amp. Again I get the same reading with red pin to power cable and black pin to RCA shield. I used a wire brush to get a solid ground both under the dash and in the trunk. My ground point for the amp is a tested and true point used by a guy from another forum, and he gets no whine at all in his install. Click here to see a picture from his install showing the ground location; it is in the lower left corner.
I have come to one of three conclusions. One is that the HU, which I bought used, might have a bad preamp section, and I was thinking of buying another HU just to test this theory. Second is there is some corrosion on the factory battery cables; all 4 gauge cables and battery terminals are brand new. Third is I just thought I might have noise induced from the speaker wire. Since it is extremely hard to run the wires into the doors I (hangs head in shame) ran speaker wires from amp to the HU wiring harness white and gray wires. I can take an extra speaker and wire and hook it up to the amp.
This is where I stand. I think I have spent more time troubleshooting than it did to install the damned amp! In closing I have used this flowchart as my first step in determining what the problem is. During step one I had no noise, and there was no noise when the RCAs were disconnected at the amp or at the head unit. There was still noise when the antenna was removed. I tried a noise filter and it made no difference. For the hell of it I tried a ground loop isolator. It removed all whine, but the sound was very hollow-sounding.
Any and all insight will be greatly appreciated!!! Thanks!
posted
hook up another persons vehicle via booster cables with theirs running and your not, listen to the stereo. If there is still engine noise then its the install somewhere. If there is no noise with another car running then its your engine.
Some things to look at at, Battery, look for cracks in plug wires and cap, also do the wires pass near any 12 wires at all? Look at crank sense wires and if they pass near 12v wires.
But first run dedicated power and ground directly from deck to battery making sure not to pass any factory wires to close.
-------------------- -Donald Hebig -All Out S.P.L. Saskatchewan's dB Drag event promoter -Check the Termpro homepage partners for the companies I support. Posts: 2622 | From: Borden, Saskatchewan. Canada | Registered: Feb 2000
| IP: Logged |
posted
I won't get to runnin new power for head unit tonight, but I tried running a spare speaker and speaker wire next to the amp. There was the same amount of noise, so speaker wires are not the problem. I tried your idea. There was an acceptable amount of whine, but there was still whine.
I always do the one of the big 3 - battery negative to ground. The engine to ground is an I gauge cable, and it's ground point is FILTHY. I'm going to run to scuff that area up and run an extra 4 gauge ground there, too. I'll let you know what happens.
posted
Tempe, You indicated that there was no noise during step one of the flowchart, the poit where it suggests shorting the RCA's by using one RCA patch cord to connect the left and right inputs together, if this is correct, you have effectively ruled out all of the power and ground connections for the amplifier as being possible causes for the problem. You have also ruled out any possibility that the speaker wiring could induce the noise as well, so now you're pretty much down to the RCA's and the head unit.
You also indicated that you tried another set of RCA's, and that did not cure the problem, so we are again looking at the head unit as a source for the noise. Another thing to consider is that you indicated a voltage reading of 12.27 volts, which is a bit low, and suggests that your battery is working at about 75% of full capacity, still able to fill the electrical needs of the vehicle, but unable to keep up with the additional demand of the new amplifier and also unable to properly filter the AC ripple in the power that it is producing. When an amplifier loses the ability to sufficiently filter the power being produced by the alternator, you get noise. Your tests have shown that the piece of equipment most effected by this problem, is your head unit.
To rule out the head unit completely, use an iPod with an RCA to headphone jack adapter cable to provide an alternate source signal for your amplifier. Power up the amplifier, with the iPod connected, and using the volume control of the iPod, supply a music signal to the amplifier. If the music plays and there is no noise, then you have again confirmed that everything in your system, except the head unit, is working properly.
Check the head unit for missing power filters on the wiring harness, and make sure that it has a good ground to the vehicle's chassis, or from the chassis of the head unit to the vehicle chassis, it is quite possible that your initial thought just might be correct, that you have a defective head unit.
posted
I have an MP3 player on my phone. I'll try my RCA to 1/8' plug cable and get a signal to the amp and see what's up.
Since the last post I ran an extra 4 gauge from chassis to engine and no improvement. Also I ran the head unit's power wires to the battery using jumper cables and again no improvement.
Mike out of curiosity which shop in Phx do you work at?
posted
Okay couldn't use phone because it has I'm guessing a 1/16" jack, so I ended up using a boombox. When I hooked it up I had a constant buzzing noise that remained constant at all volumes. I did not have this problem when I hooked it up to my home stereo. When I turned the engine on nothing changed, and there was absolutely no RPM-dependant engine whine. It looks like it is the RCA-out on the head unit.
Also when I first installed the head unit a year ago (Craigslist $40 special) I hooked up the RCAs to my crossover in my Ranger. There was no whine at all.
posted
hook the power for the HU up to another battery. Separate of the vehicle. Start the civic and see if there is noise. If there is no noise, it's on the power side of the HU. If there is noise, it's on the rca side. You can fix from there.
posted
have you tried it with a different amp? or same amp in a "clean" install in another car?
another option, run an extension of someone else's rca's from another car...is the noise still present?
do you have the power cable from the battery running across the engine bay to the other side? going over the engine in some fashion?
Posts: 5529 | From: Columbus, OH - formerly FL | Registered: Oct 2003
| IP: Logged |
posted
I had the same problem with my prs880 deck.Ignition noise, ground loop noise, more noise with the blower motor running, ect. I tried grounding the rca's to the deck=same noise, ran the deck ground to the battery=same noise, ran the power to the deck off the battery=same noise. I ended up running a set of shielded rca's over the seats to the amp, noise went away. I rerouted the exsisting rca's down the opposite side of the car=same noise. I removed the exsisting rca's and installed 2 pairs of shielded rca's=no more noise!
Team Neo - Eric
Posts: 511 | From: streetsboro,oh | Registered: Jun 2005
| IP: Logged |
posted
many shielded RCA's are also directional. many directional RCA's are also shielded. make sure you connect the correct end to the source unit
Posts: 5529 | From: Columbus, OH - formerly FL | Registered: Oct 2003
| IP: Logged |
quote:Originally posted by Andy Jones: hook the power for the HU up to another battery. Separate of the vehicle. Start the civic and see if there is noise. If there is no noise, it's on the power side of the HU. If there is noise, it's on the rca side. You can fix from there.
I'm going to try that later on tonight once it cools off a bit. I'm really thinking it's the battery. I retested the voltage at the battery. I was told I should get an reading of less than 0.5 volts AC with the engine on. Holy crap it was like 25.87 volts AC!!! With engine on for about three minutes the reading was only 12.87 volts DC. I'm going to have the battery tested. Here in AZ you're lucky to go a year or two before your battery dies I was also told to try installing a capacitor. I happen to have a Lightning Audio 1 farad cap laying around. I might try that.
quote:Originally posted by D-Bass: have you tried it with a different amp? or same amp in a "clean" install in another car?
I've been putting that off, as the amp in the Civic accepts bare wire, whereas I have ring terminals on the wires for the amp in my Ranger. Plus the amp in the Ranger is under the seat, so it's a PITA to remove.
quote:Originally posted by D-Bass: another option, run an extension of someone else's rca's from another car...is the noise still present?
I ran RCAs from the Civic HU to my Ranger's xover. Everything sounded okay. I ran the same RCAs from my Ranger's xover to the Civic's amp and it sounded so bad. Midrange was almost absent. Some instruments were audible, while others could not be heard at all. Plus there was whine when the Civic's engine was on.
quote:Originally posted by D-Bass: do you have the power cable from the battery running across the engine bay to the other side? going over the engine in some fashion?
Nope. It goes straight through the firewall straight back.
quote:Originally posted by tekk45: I removed the exsisting rca's and installed 2 pairs of shielded rca's=no more noise
I'll stop by a shop and see if they have a pair of shielded RCAs I could use to troubleshoot.
Also today I tried to bypass the preouts on the head unit with an LOC. I had the same amounts of whine with the engine on. Even with disconnecting the speaker output wires from the LOC as long as I had the RCAs connected to the LOC I had whine. I did make sure I grounded the LOC, too.
I'm getting so pissed. I've spent more time troubleshooting this whine than I ever have. I just want to be able to turn the gain up to match the HU and have decent output from the amp. Right now the gain is low enough so that the whine is somewhat bearable
posted
I went to Autozone to have the battery and alternator tested. The battery is only at 60% charge even though the engine was running for 25 minutes prior. The results of the alternator is not good. There are good diodes, the regulator is dying, and there is low output.
posted
^to see if that is your noise, just hook a pair of jumper cables up from your truck to the car and start them both. The car then has the truck's electrical system backing it. If your noise is gone, it's the charging system.
posted
Temps, Sorry i hadn't got back to you since Sunday, work has kept me really occupied. I didn't even know you had a topic on here about the noise.
I think just about all the bases have been covered here (or on the phone).
If I get the beater truck up and going I'll trek out phx and take a look at it.
Just a thought, do you notice if there is any clicking noises coming through when you switch on your headlights? also, Does the noise get louder if you turn on more accessories (ac, rear window defroster etc.)?
BTW- Mr. Abeita, good to see you around!
-------------------- Yes this is my sig, no there is nothing for you to see. Quit looking at me, nothing is going to happen. Stop staring at me, cut it out, leave me alone.... Posts: 3085 | From: AZ | Registered: May 2003
| IP: Logged |
posted
ground loop isolator didnt solve anything?? the once and only time(knock on wood) I have experienced whine is when my pully tensioner for my alt went. Had it replaced and the whine was gone.
-------------------- SCA DC Sound Labs PowerBass USA T3 Audio Soundstream Car Audio Posts: 6636 | From: Buffalo, NY | Registered: Feb 2001
| IP: Logged |
posted
First I shortened the ground cable at the amp. Yes it was long just for now until the amp was mounted. I chopped it at 18". With the windows down and noise coming from the engine running I heard no whine. Once I rolled up the windows I could hear it. Maybe the noise was reduced a bit.
As per Andy's last post I hooked up both vehicles and started them both. The noise went away with both engines on. When I turned off my Ranger's engine the noise came back.
![[Smile]](smile.gif)
![[Frown]](frown.gif)
Printer-friendly view of this topic