Audio Control DQS issues

Post by **smgreen20** » Thu Jun 18, 2009 4:44 pm

Some of you might recall I had an issue 2 months back involving my DQS. I forgot to turn the power off when removing the sub box and the right speaker terminal grounded out on the chassis and now there's an engine whine noise in the right side channels only when the DQS is installed. If I remove it, bypassing it and there's no whine.

So I sent it in to Audio Control for repair and got it back this past Monday and put it in. What do you know, the whine is still there on the right side channels only.

I called AC and they told me that they put a brand new board in it and that I basically have a new DQS. He states that they're very sensitive to ground loops due to their digital circuitry. He suggested that I run a ground straight to the battery and not use the chassis and that when I grounded out the speaker lead it weakend something in the ground.

I did what he said and ran jumper cables from the ground distro block to the neg post of the battery to bypass the chassis ground, still whine. I'm going to try and install it in a friends truck for a few minutes to see if it still has whine. If not I'm wondering if I need to ground the RCA's or something.

In doing so, how/where would I ground the RCA's? My system flows like so,
HU, 3 sets of RCA's to the DQS, from the DQS 2 sets to the ZX450v2 and the 3rd set to the BassCube and another RCA from the BassCube to the ZPA0.5. Do I need to ground all 7 sets of RCA's? If so where? How? Resistors needed?

If this fails I'm going to have to call them back and get crappy when I don't want to and the guy I talked to, Eric, was pretty cool. They were one of the nicest companies I've ever had to deal w/concerning repairs.

I just don't see how it could be a ground loop if it's only the right side channels that have the whine, why not the lefts too? I've also tried a ground loop noise filter both on the RCA's and on the power input.

Your thought please, thanks guys.

dBincognito · Post by **dBincognito** » Thu Jun 18, 2009 4:56 pm

If this fails I'm going to have to call them back and get crappy when I don't want to and the guy I talked to, Eric, was pretty cool. They were one of the nicest companies I've ever had to deal w/concerning repairs.

You will get nowhere....AC does the WORST repair work ever.....they never fix anything, and keep charging you for it....that's all I will say

I LOVE their products....just don't ask them to fix anything

From my experiences with them.....they never fixed anything....told me a bunch of BS....and just kept taking my money....they won't be " repairing " any more of my stuff

davewaibel · Post by **davewaibel** » Thu Jun 18, 2009 8:11 pm

good luck on getting anybody else to touch their stuff for flat fee 35.00 repair

Post by **smgreen20** » Sat Jun 20, 2009 7:58 pm

I called them back and talked to Erik. He told me to send it back in and that he'll take it in hand and oversee it's repair himself.

trckydve · Post by **trckydve** » Sun Jun 21, 2009 2:57 am

I've dealt with Erik a couple of times and he took care of me. Very good guy. I've also had a few bad experiences with AC when I wasn't dealing with him.

dBincognito · Post by **dBincognito** » Sun Jun 21, 2009 5:04 am

davewaibel wrote:good luck on getting anybody else to touch their stuff for flat fee 35.00 repair

I paid ALOT more than that....when did they start charging that ?

I paid $400 and my DQXS was still broken, after sending it back 4 times......and they surely did not charge $35 flat rate.

They would deny that it did not have a hum in the sub channels, when it clearly did.

Post by **Jacampb2** » Sun Jun 21, 2009 5:48 am

Is the DQS a "unity gain" device, or does it incorporate some form of line driver? Just thinking out loud, but it is possible that the noise is actually on the RCA, either originating at the HU or being picked up along the way and that the reason you do not hear it with the DQS bypassed is that the amplifier has better noise rejection than the DQS. If the DQS doesn't filter the noise, and is amplifying the signal, well it may push it high enough that the amp can no longer filter it out.

I am not familiar with any AC products, so this is just a thought, and although possible, it is not that likely-- If they did replace the board, then the only two explanations are the new board is bad in exactly the same way, or that the noise is always there and your amp is just filtering the noise.

Did you ever try removing the HU from the equation, maybe use a portable CD or MP3 player as a source?

Good Luck,
Jason

dBincognito · Post by **dBincognito** » Sun Jun 21, 2009 5:54 am

Here you go Jason, this will help

Post by **Jacampb2** » Sun Jun 21, 2009 6:05 am

Thanks Randy! The specs in the manual show that it does have a built in line driver. If you get it back and it still does the same thing, I would definitely consider trying an alternate source if you haven't yet.

Later,
Jason

Post by **smgreen20** » Sun Jun 21, 2009 9:43 am

Yes I tried a different HU. That was the very first thing I did. To further eliminate anything other then the DQS, I ran the right side signal RCAs through the left in/outs of the DQS and no whine, but when I ran the left side signal RCAs through the right in/outs of the DQS there was the whine.

There's no if's, and's, or but's about it now, it IS and HAS to be the DQS. I even put it in a friends truck and the whine was still present.

No, it's not unity gain. 7.5v rms in and 7.5v rms out. Makes me wonder if I'm actually loosing out in that department being that my HU has 8v preouts.

dBincognito · Post by **dBincognito** » Sun Jun 21, 2009 10:04 am

smgreen20 wrote:Yes I tried a different HU. That was the very first thing I did. To further eliminate anything other then the DQS, I ran the right side signal RCAs through the left in/outs of the DQS and no whine, but when I ran the left side signal RCAs through the right in/outs of the DQS there was the whine.

There's no if's, and's, or but's about it now, it IS and HAS to be the DQS. I even put it in a friends truck and the whine was still present.

No, it's not unity gain. 7.5v rms in and 7.5v rms out. Makes me wonder if I'm actually loosing out in that department being that my HU has 8v preouts.

Have you ever measured the voltage on the RCA's coming out of the HU.....I seriously doubt you would get 8v....even though your HU claims it....this is " Marketed" voltage rating...not " True"

If you do get 8v....let me know, I will want to buy one of those HU

Post by **smgreen20** » Sun Jun 21, 2009 3:36 pm

A 1000 Hz tone at -0 dB at 75 out of 80 on the volume it measured 7.3 volts. I stopped at 75 due to possible distortion at full volume.

dBincognito · Post by **dBincognito** » Sun Jun 21, 2009 3:48 pm

smgreen20 wrote:A 1000 Hz tone at -0 dB at 75 out of 80 on the volume it measured 7.3 volts. I stopped at 75 due to possible distortion at full volume.

What HU ?

Post by **Jacampb2** » Sun Jun 21, 2009 5:07 pm

I am gonna guess eclipse... They are the only HU's I have found which consistently meat their spec. They are also one of the few HU's to have a SWMP which gives them the ability to hit the HV output spec.

dBincognito · Post by **dBincognito** » Sun Jun 21, 2009 5:09 pm

Jacampb2 wrote:I am gonna guess eclipse... They are the only HU's I have found which consistently meat their spec. They are also one of the few HU's to have a SWMP which gives them the ability to hit the HV output spec.

If it is Eclipse than that is cool, that means I don't need to buy it....I already have it

Post by **smgreen20** » Sun Jun 21, 2009 7:34 pm

Jason is right, I have an Eclipse CD8455

davewaibel · Post by **davewaibel** » Sun Jun 21, 2009 8:02 pm

they have been doing flate rate for over 6 months, possibly longer- I have an email from erik confirming that

dBincognito · Post by **dBincognito** » Sun Jun 21, 2009 8:05 pm

davewaibel wrote:they have been doing flate rate for over 6 months, possibly longer- I have an email from erik confirming that

F***......I threw my DQXS away....I got mine repaired over a year ago.....and each time I sent it to them it costed me $100+shipping both ways

4x and it STILL had the same probelm

I was so mad I went Office Space copier machine on it's ass

Thumper88 · Post by **Thumper88** » Sun Jun 21, 2009 8:24 pm

you went office space style on a $600 piece of car audio equipment?

Post by **mhyde71** » Sun Jun 21, 2009 8:32 pm

whats office space style? wheres that from?

Thumper88 · Post by **Thumper88** » Sun Jun 21, 2009 8:53 pm

mhyde71 wrote:whats office space style? wheres that from?

http://www.youtube.com/watch?v=M3jUl7KPpL4

oldskoolmseriesfan · Post by **oldskoolmseriesfan** » Sun Jun 21, 2009 9:31 pm

I was so mad I went Office Space copier machine on it's ass

CLASSIC

dBincognito · Post by **dBincognito** » Mon Jun 22, 2009 4:50 am

Thumper88 wrote:you went office space style on a $600 piece of car audio equipment?

When that piece of equipment has cost you $1,000 and it still doesn't work, and AC wants another $100 to look at it again......yes sir, wouldn't be the first piece of equipment I destroyed.....and probably not the last.

Post by **stipud** » Mon Jun 22, 2009 6:17 am

dBincognito wrote:
Thumper88 wrote:you went office space style on a $600 piece of car audio equipment?

When that piece of equipment has cost you $1,000 and it still doesn't work, and AC wants another $100 to look at it again......yes sir, wouldn't be the first piece of equipment I destroyed.....and probably not the last.

But you paid them again and again to fix the same issue that they couldn't fix in the first place? I would have expected them to fix it properly the following times without charging you any more. If they asked me for more money I would have said hell no... let alone after the third time!

dBincognito · Post by **dBincognito** » Mon Jun 22, 2009 6:22 am

stipud wrote:
dBincognito wrote:
Thumper88 wrote:you went office space style on a $600 piece of car audio equipment?

When that piece of equipment has cost you $1,000 and it still doesn't work, and AC wants another $100 to look at it again......yes sir, wouldn't be the first piece of equipment I destroyed.....and probably not the last.
But you paid them again and again to fix the same issue that they couldn't fix in the first place? I would have expected them to fix it properly the following times without charging you any more. If they asked me for more money I would have said hell no... let alone after the third time!

You said once before that you did not have a DQXS, if you did I'm sure you would understand that getting it fixed was of the upmost importance to me....nothing else can touch it....I did have a yellow one though, gave me a excuse to buy a different color.

and at the time, new was $650+.....so getting it "fixed" was much cheaper.....even though it didn't turn out that way