x_Batman_x

iTrader: (3)

So my new audio set up has a but of noise, its annoying and I dont know what to do about it. I'm running an eD NINe.4. Two of the channels are powering eD e3.65i components in the front, nothing is hooked up to the other two but they will be used to power an eD SQ10 when it comes.

I'm basically suffering from alternator whine (even though sometimes it sounds like I have a turbo, I want it gone ) and that basic hiss that is most audible when nothing is playing (ie music paused or system on stand by). I've read the 10 commandments for a Noise Free set up but I already followed most of the rules and I'm still having problems. The power wire runs down the opposite side of the vehicle than the RCA signal cables (they are only near each other for about 4-6" or so). I drilled a new hole for a ground (though I haven't tried sanding down the area yet). And I don't want to use noise filters. I feel like if im using eD equipment which is supposed to be high quality stuff, I shouldn't be having this problem. Do you all have any suggestions?

TwztedtC

ground loop isolator

also if you have your rcas and power wire ran on the same side you need to run one on the other side of the vehicle

check your ground

x_Batman_x

iTrader: (3)

whats a ground loop isolator?

also I specified in my OP that the RCAs and the power wire are on opposite sides

and what do you mean check my ground? should I sand the area a bit for better connection or what..?

thanks

ecko04

He means that noise generally means you used a bad ground, i.e. the ground used is not a true ground but rather a floating point.

Start the car and rev the engine....do you hear any whine from the speakers?

If so you are also picking up alternator whine.

What can fix this problem is first finding a better ground.

Next, do the ground wire kit thing as denoted here:

https://www.scionlife.com/forums/viewtopic.php?t=29261

That should help reduce the noise a little bit.

The last resort would be to use ground loop isolators. The typically degrade audio quality and should only be used as a last resort.

The best thing to do first is to find a different ground and sanding should not be necessary.

x_Batman_x

iTrader: (3)

lol okay I am not trying to be a d*ck so please dont think I'm being ____y I just think its funny enough to point out how many people fail at reading the first post as I also specified in the op that I was getting alternator whine lol. I'm not mad or frustrated and I really appreciate your help I just had to point it out

anyways I went out, removed the stock sub, and checked the ground and found that it was only finger tight and there were burrs. So I figured while i was there I'd sand off the burs and the area just for good measure. Funny thing I over sanded so that the bolt wouldnt thread and had to sand another area about an inch higher and re drill haha

anyways here are some pics of where I grounded:










after tightening and sanding there is still that hiss. I didnt check to see if the alternator whine was still there because I didnt want to start my engine but as even moving the throttle body with the engine off created fluctuations in noise so I imagine the whine wont be fixed either. Is my location a bad spot for grounding? if so where do you recommend?

thanks again for the help :-)

tCjosh

iTrader: (8)

yep, that's a bad spot for grounding... I had the same problem when I first put my system in, but by just moving my ground wire to the middle bolt that holds the rear seat, solved my problem... you should do that too if your ground wire is long enough.. hope this helps..

x_Batman_x

iTrader: (3)

I have more wire, I think I'll go try that now

*scurries off to garage*

datdude1119

are u running the stock deck?

x_Batman_x

iTrader: (3)

whew okay now im frustrated lol. I have spent way too much time working on my car tonight for a highscooler on sunday with homework still left untouched hah. I had to throw together a new ground cable but the terminals I had were to small for the seat bolt so I went through 2 of em trying to get the hole big enough and then after I got everything hooked up.... THERES STILL NOISE! arg i'm ____ed. I'm keeping the amp grounded on the back seat bold and I sealed up the two holes that I originally drilled...

So does anyone have any other ideas?? im pretty sure the ground is not the problem because I hooked up my volt meter to the + and - terminals of the amp and the reading matched that of my Scanguage. I also used my ohmeter to measure the resistence between the 2 ends of the ground cable and also between one end of the cable and another spot on the chasis and both experiments measured 0 ohms of resistance so yeah its not the ground lol.

x_Batman_x

iTrader: (3)

oh yeah and datdude, I have an after market deck

and one last detail I forgot to mention, not sure if it matters but the gain is cranked all the way of because the speakers' RMS power is 150w and with the gain turned up all the way I'm still only pushing ~88.36w which is enough power for me, but I dont know if pushing the amp so hard would cause noise....

Eltaco

If the gain on your amp is turned all the way up, it will pick up every little bit of RF your car and other passing cars produce. Personally I would run a ground all the way to the battery, that way there is no "loop" in your ground. Another trick that I have used to limit some of the RF noise is run RCA's that are long enough that you can loop them a couple of times near the amplifier, not tight loops, just about 4" in diameter.

x_Batman_x

iTrader: (3)

I'm assuming RF stands for radio frequencies...?

I'm not sure what this "loop" you're talking about, could you elaborate?

My RCAs actually happen to already be looped like you described... why would that help though?


and MOST IMPORTANTLY Happy Birthday :-)

Eltaco

Thanks.

Consider your battery is grounded under the hood, your amplifier is grounded in the hatch area. With that being said your ground is "looping" through the chassis.
RF is Radio Frequency, anything electrical has a chance to emit RF, in the case of the vehicle alternator, it produces AC, alternating current that has to go through diode(s) to be converted and regulated to about 14.8 volts. AC produces quite a bit of RF which in a mobile amplifier can produce "noise" in the audio frequency range 20~20,000hz. And looping the RCA cables reduces the chance that they can act as an antenna. One last note, I am not a professional installer and only set up car stereo's for friends as a hobby.

x_Batman_x

iTrader: (3)

thanks for the info.

I would REALLY rather not run a ground cable down the full length of the car though....

anyone else?

izedaman

If your gain is maxed, you need to have very good quality RCA's and short as possible, try another set direct from headunit to amp if you have a descent 6' from your home entertainment center, it should reach, just to see if your amplifying the noise from old or cheap rca's
This is assuming you have no noise with your rca's unplugged, and motor on/amp on

tc-guy

just a lil observation batman but i noticed that u have the rca's laying over that fat power wire there right where they split to opposite sides of the amp. even if u have them running down different sides of the car if they are that close at that point rf can go from the power cable to they rcas and out through your speakers. seperate the rca's completely from the power cable and see if that solves the problem.

kileil

I've found most noise problems start at the deck (assuming decent components, which yours look good). Instead of grounding through the stock harness, try grounding into that fat metal tube behind the deck.
If that doesn't work, stop by a local audio shop and ask if they have any of the filter boxes that come on old school pioneer decks. Its a little box that filters ac ripple off the 12v constant going to the deck. Its better than the rca GLI's in that it doesn't affect the signal being passed to the amps

edit: and yes, the advice above about keeping signal away from power, and turning down the gains a touch is also good advice. Rule of thumb for gains is no more than 3/4 of max, the rest is noise. better to increase the signal through a deck w/ higher V's output than to crank the gains.

TwztedtC

I would still try a ground loop isolator. That is an inline noise filter that goes on the RCAs you can pick up at an electronics store like Circuit oh wait they are closing lol

ecko04

Ground loop isolators should be the last thing used, they degrade the sound quality.

The ground should be as short as possible; running a ground the entire length of the car will increase the chance of noise. People do run them from the battery but I just don't prefer it or think its a good idea.

The gains should not be turned all the way up on any amp, that will also increase the chance of noise and alternator whine.

The seat belt bolt is not a good choice of a ground.

Here is a video of the guys over at eD creating a ground. I don't grind off paint but they do.

http://www.youtube.com/watch?v=xVyLDvRAzds

Also, another fix for alternator noise, is to run small gauge wire from the grounding at the source (head unit) to the amp. This way, you avoid any resistance the chassis might give you.

Please be sure you don't drill into the gas tank!!

x_Batman_x

iTrader: (3)

well shoot now I'm ____ed that I wasted wire setting up the ground on the backseat bolt arg... I cant watch the video now cuz I'm at school but I'll check it when I get home, create a new ground, reroute the RCAs, and back the gain off a little bit...