alt whine from audiocontrol eql

hello everyone. i have a quick question. a few days ago i installed an entire system minus any subwoofers. heres what i have in the order that it is installed in my system:

jvc chameleon head unit

audiocontrol EQL

kicker kx3 crossover

alpine PDX-F4 amp

diamond audio D9 2-way components

knukonceptz kollosus 4ga power and ground wire

knukonceptz krystal kable RCA's

Everything is working as it should and it sounds great but i get a slight alternator whine that i can hear if the music goes quiet or if i turn the stereo down.

it doesnt get louder with the music it pretty much stays constant except that it gets louder when audio is running through the lines as opposed to the radio just being off. i only get noise if the truck is running.

my rca is ran to avoid coming close to any power wires that i can see, all signal processing is done on the passenger side and the amp is under the driver seat.

all ground spots were sanded down to bare metal

the kicker kx3 and the audiocontrol are mounted right next to each other on the same piece of wood and they share a common ground point although the ground wire is a little long for my tastes, maybe 18 inches or so. do you think this could be a problem for them to be next to each other and grounded to the same spot?

the only way that i can get the whine to be quieter is to turn down the output on the kx3, im running a by amplified system with the kx3 as the main crossover so naturally the high piched noise only comes from the front output that i have running to the tweeters.

for all intents and purposes i dont think that i should have any noise in my system which is why im having a hard time tracking this down.

this is the strange thing, the audiocontrol has a built in ground isolator switch that it says you should flip if you have noise, the switch is under the cover you have to take out some screws to get to it. so i try to do this and i find out that there is no switch inside. the circuit board has a spot for it and its labeled on the board too but there is no switch to be found. do you think that not having a switch at all could be the reason for my noise?





this is the spot on the board where the switch should be and its marked with two lines drawn on top and bottom that go straight to a blank spot on the board where it even looks like it was pre wired to have a switch there. so with that said, can anyone confirm for me that it is supposed to be there and that it is missing on mine. the only other option would be that it might have been taken out of the design for some reason. and for the record i didnt break it off and the switch wasnt inside the case as if it had been broken off, its like it was never there to begin with.

so please, if anyone has any ideas i would welcome them. thanks

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I do not know why you are surprised that you have noise.  Audiocontrol units were notorious for engine noise.  Try a ground loop isolator on the input of the EQL.

i know about their noise issues but honestly no body else really makes any good equalizers for cars these days that dont require you to use specific head units. i really wanted a hald din eq but nowadays they are all the same and they are all garbage. this was all i could find that had the features i was looking for and fit my budget. if you can point me to something better i guess ill just have to save up the money to get it.

do you have any opinion about the missing switch?

do you think i could put a capacitor on the power supply to stop the noise?

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The reason you can not find a decent outboard EQ is because any decent deck has a digital EQ built in.  I seem to remember the ground loop isolator usually taking care of this issue. 

They may have eliminated the switch to cut cost.  I never remember that switch fixing any issues.  A capacitor will not get rid of the noise.  The noise is not coming from the supply. At least that was the case 20 years ago.  If the unit is the same as it was back then, or if it is a unit from back then, I am pretty sure the ground loop isolator will fix it.  If you do use one, most of them have gain.  This means that they are directional, there is an input and an output, if you connect it backwards the gain will become a reduction.  A Pac-audio.com SNi-1 has a gain of 1 : 1.25, if installed backwards it becomes 1 : .75

well my JVC has a built in 7 band but i like how the eql has 7 bands for left channel and right channel plus it has 6 extra bands just for bass frequencies, i really love the equalizer except for the noise it makes.

im pretty sure myself that a GLI would fix the noise but i still would rather not have to use one at all. i dont know if it would alter the audio signal in any way which is something i dont want to have happen. thats wy i was trying to get other ideas but i guess ill try it out anyway

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Hi, John here from AudioControl. I'm guessing you have a very old board. Newer boards will have a jumper pad there. I'll get back to you as soon as I talk to the engineer who did that board...it was before my time.

But I want to mention two things:
a. Since I have been here (4 years) we have had no noise issues. Those came from the fact that the very early units had a great deal of gain. Up to about 50dB. So, if there was a grounding issue you had to fix it or you would hear it. The company long ago changed the gain structure to about 24dB total.
b. A ground loop isolator will indeed fix a whine. However it will also reek havoc with the bass response. PAC actually used to tell you that they sacrifice bass response to get rid of the whine. Avoid them if at all possible.

If you like you can call me at 425.775.8461 after 12:00 pacific time and we can run through the system and how to change the signal ground reference point on that board.

John

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JBorges

Here's an experiment...Take a jumper wire and short the shield of one of your RCAs at the signal inputs to the ground connection at the power plug. What happens to the whine?

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JBorges

 Just for my curiosity what vehicle is this?  Are you certain that the AudioControl EQL is the culprit?  Have you bypassed the EQL and the noise gone away?  If I'm reading you right the audio signal goes from the deck to the EQL than out to the Kicker KX3 Crossover and from there the Alpine PDX-F4 amplifier?  Have you removed either the EQL or the Kicker or both and see what happens when it is just the signal from deck to amp?  Also, on the PDX do you have the settings on full range/ hp?  What is the setting on the deck as well?  Are you utilizing the Diamond Audio Crossovers and are they attenuated at +3db or +6db?  The devil is in the details.

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remarkable53

ooh cool, alright im going to do my best to answer as much as possible.

ac john, thanks for the input and im kind of sad to hear that i have an old EQL board, i guess new is new no matter how long its been sitting on a shelf, whats strange is that even the manual that came in the sealed box mentions this non-existant switch but oh well.

just for fun i got a PAC GLI and it took out about 80% of the noise which is fine for now but i want it all gone, im already loving the processor so i would hate to have to change it out. i havent shorted the RCAs yet or really done any hard core testing because ive just been a little busy. i work on sound all day so its hard for me to motivate myself to work on my own stuff, but ill definitely try these out. and ill try to give you a call at some point.

remarkable53, no i have not truly isolated the noise for sure 100%, i havent bypassed either the audiocontrol or the kicker. what pulls me toward the audiocontrol being the culprit is that i cant get the noise to go away by turning down the gains on the audiocontrol which means that its either in the output of the EQL or the input of the kicker.

ive had another kicker kx3 in my last system and it was extremely quiet and i suspect this one is too. if it was coming from the output of the kicker then i probably wouldn't be able to stop the whine at all.

plus its hard to bypass the kx3 because it is my only crossover in the system. im not using the passive crossovers that came with the diamonds and im not running the hpf on my deck and the amp is set to full pass. the only other filter is the subsonic which is prebuilt into the EQL and set at 31Hz i think. im afraid that if i bypass it ill damage the tweeters in some way.

i hope this answers your questions



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ok, i just went out and bypassed the EQL and i still get noise with just the kx3 hooked up and no noise filter inline, however, the noise isnt alternator whine, it doesnt go up and down with engine rpm it is just a steady high pitched noise.

the noise i had before with everything hooked up and no noise filter was basically a combination of alternator whine probably from the EQL and this constant noise from the kicker.

so, any thoughts?

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Quickly brighten and then dim your dash lights. Does this alter the steady pitched noise?

Occasionally a product can have a defective component that can cause noise. That is a defective product. However, beyond that...products (including AC and Kicker) do not cause or create noise. However every time you insert another item into the system you create another path that can let noise in. Also, a poorly designed piece can create more than one path and make it that much worse.
The kicker could have a bad internal component but it could also have a component looking for a better ground. This could cause a noise separate from your alternator whine. So first check your grounds again. I don't know what car you have but if a new one, watch out for "quiet metal". That makes body panels quieter, but it also makes them lousy grounding points. Go to a frame and make sure the battery has an upgraded ground to the frame.
Then take 2 jumpers and run one from the EQ ground to the shield on one RCA's as I said earlier, then do the same thing for the Kicker crossover. See what happens.

John


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JBorges

i am an idiot wrote:

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Quickly brighten and then dim your dash lights. Does this alter the steady pitched noise?

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i dont have a dimmer. and its not hooked up on my radio either if thats what you were getting at.

im sorry guys im forgetting posting 101, i have a 2011 nissan frontier four door.

as far as i have noticed, none of the electronics in my truck has any influence on the noise, the lights and turn signals dont change it and the ac doesnt change it.

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I am concerned with the PWM power supply for your dash lights of the vehicle.  Not the lights in your radio.

ok well like i said, i dont have a dimmer switch for my dash lights. is there any other way i can get you the info you want? i just had my wisdom teeth taken out today so you will have to give me a while to perform any kind of tests but they will be done.

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I have never seen a vehicle that did not have a dash light circuit that could not be dimmed. If your lights are not on, this is not your problem. The power supply for some dash lights emits a high frequency noise. If you dim and brighten the lamps you can hear the pitch change. If your lights are off and you still have the noise, it can not be your lights.

yea i thought it was strange too but sure enough i have no dimmer.

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ah ha, this morning i ran a new 4 gauge ground from battery straight to the frame and it instantly fixed most of the noise all together. right now i can still hear noise if i have the volume all the way down and it actually a little bit quieter than when i had the noise filter in line so for now im happy.
i still need to figure out how to achieve total silence so maybe i might re do my ground for the EQL and KX3 and run them straight to the frame too, possibly even the amp but im not sure about doing this because it would make the grounds way too long for my comfort and they are already kind of long to begin with and im making up for it by oversizing my wire considering my total system draws less than 60 amps.

but for now, thanks to everyone who took the time to help me out and give me some ideas. gracias

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lancytaylor wrote:

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i think you are too insentitive about the noise. in fact,a little noise is quite normal.

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i guess, it is and it isnt normal, 99% of people out there wouldnt even notice the tiny bit of alternator whine, but this is my own personal system so why settle for anything less than as good as i can get. if it turns out that i cant get the noise out then im not going to lose any sleep over it but i am going to try everything i possibly can. 

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alright, time for a status update. i installed a noise filter inline with the constant power supply of the EQL and the KX3. now i dont have any detectable noise, BUT i have a question about how i am using the active crossover in relation to how it's hooked up to the alpine amp.

my problem is that im pretty sure i am getting some kind of distortion somewhere between 1kHz and 3kHz which is the range at which my crossover is set (about 2.2KHz is the crossover point) it sounds like static or maybe crackling and honestly im still not entirely sure that it is not just something that is in the song itself but to me it just sounds like extra noise.

i THINK that it might be because of a difference in RCA voltage of the mid signal and the tweeter signal comming out of the crossover. example: i have the left mid and left tweeter running to channel 1 and channel 2 of the amp. i did it that way because i wanted each gain on the amp to control one whole side instead of one gain for the tweeters and one gain for the mids.

the difference in voltage exists because i have the mid output from the xover set higher than the tweeter level. so channel 1 and channel 2, which share a common gain, are not seeing the same voltage input. does anyone know if this would cause a problem with audible distortion considering this is a high speed class D amp ( PDX-F4)?

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well ive tried everything i can do and all i can do is assume that what noises i hear are in the music. its not uncommon for hard rock and metal bands to use distortion effects on instruments and ever the singers voice plus i only hear the noises when the guitar kicks in with distortion, when the music is clean then the audio is clean. this just all sort of tripped me out because ive never been able to hear the music this good to notice these small effects that get thrown into the recording. i guess for now its mission accomplished

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