DiyMobileAudio.com Car Stereo Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
109 Posts
Discussion Starter · #1 ·
Hi everyone, I just purchased a NIB audiocontrol DQS and am having some trouble setting the input/output levels on the unit. If I go by the owners manual the levels seem set too high and produce a "hiss" in my speakers. eq in all flat positions. HU all flat positions.

I have tried setting the input lower than half way with the output higher than half, both at half, both more than half etc. Everything I try seems to still introduce hiss UNLESS I turn both the input and output lower than half, that sounds the most 'clean' however my amplifier gain then has to be turned up more to compensate for the lower input it's getting and I'm afraid of over working my 4 channel amplifier. If set to half on both it produces less overall sound output than when I had HU straight to my amps.

Right now I have it going to a JL hd600/4 and a rockford sub amp.
My HU supposedly is 4v x3 however I don't think it's even close. Without the eq I had no noise whatsoever before.

If I set both the input and output to half, without touching my amplifier gains the overall sound output is LESS than if I have it straight from hu to my amps. It is basically attenuating the signal from my headunit when set to half on both. So my question is: Is it better to leave this at half on both, or turn it a little less than half and turn up my amp gains more? As I said above, if I turn either one of the input or output over half then I get hiss but a stronger signal... I have tried very carefully to keep all signal cables and power/grounds away from each other and I don't think that is the issue. I had zero noise (inaudible anyway) until I put in this eq.

Any advice on level settings of the eq would be appreciated. I also have a dmm to measure input output of the rca's if that would help anything?

Thanks in advance for any help I would really appreciate it!
 

·
Registered
Joined
·
12,053 Posts
Hi everyone, I just purchased a NIB audiocontrol DQS and am having some trouble setting the input/output levels on the unit. If I go by the owners manual the levels seem set too high and produce a "hiss" in my speakers. eq in all flat positions. HU all flat positions.

I have tried setting the input lower than half way with the output higher than half, both at half, both more than half etc. Everything I try seems to still introduce hiss UNLESS I turn both the input and output lower than half, that sounds the most 'clean' however my amplifier gain then has to be turned up more to compensate for the lower input it's getting and I'm afraid of over working my 4 channel amplifier. If set to half on both it produces less overall sound output than when I had HU straight to my amps.

Right now I have it going to a JL hd600/4 and a rockford sub amp.
My HU supposedly is 4v x3 however I don't think it's even close. Without the eq I had no noise whatsoever before.

If I set both the input and output to half, without touching my amplifier gains the overall sound output is LESS than if I have it straight from hu to my amps. It is basically attenuating the signal from my headunit when set to half on both. So my question is: Is it better to leave this at half on both, or turn it a little less than half and turn up my amp gains more? As I said above, if I turn either one of the input or output over half then I get hiss but a stronger signal... I have tried very carefully to keep all signal cables and power/grounds away from each other and I don't think that is the issue. I had zero noise (inaudible anyway) until I put in this eq.

Any advice on level settings of the eq would be appreciated. I also have a dmm to measure input output of the rca's if that would help anything?

Thanks in advance for any help I would really appreciate it!
no such thing. you set the DQS input the same you would an amplifier. set the ouput to match the input of the amplfiier. if that means you set the output lower and the amp input higher to compensate, then you are getting the same output at the amplifier. the amp is only gonna put out however many watts it has. the gain is not a volume knob. if you have to turn it up to match the output of the DQS, then it is not hurting anything.

all that said, how do you have the input set on the DQS? if I remember right those have the ability to have balanced and unbalanced input. make sure you have the correct setting for your HU. keeping the input low and the output high should give you the least amount of noise. Also make sure you have the unit grounded well.
 

·
Registered
Joined
·
109 Posts
Discussion Starter · #3 ·
Thanks for that response. I realize that gains are not volume controls, I just had the impression that I needed to have maximum input signal strength going to my amplifiers. Like I mentioned, if both the input and output are set at a zeroed center position it actually attenuates my overall sound level more than when I just had the HU going straight to the amps. If I turn the output level higher or the input level higher than half I get hiss. Only clean signal I can get is when I turn BOTH the input and output below center position. I just checked and my HU has unbalanced outputs and the audiocontrol dqs ships in the unbalanced position. However, I may still open it up and make sure that it is indeed in the unbalanced position. The instruction manual does not tell me how to even do this with the jumpers, although it may be self explanatory upon opening the unit. As far as power and ground, I'm running it off of the same power/ground/remote as one of my amplifiers with 4awg awg copper cabling. I may try grounding it separately to see if that helps in this situation.
 

·
Registered
Joined
·
12,053 Posts
ok, just checking. alot of people dont have a good grasp on what the gain pot is for.

what if you turn the input all the way down and just use the output? This will make the input least sensitive.

if you pull the input RCAs off, does the hiss stay or go?
 

·
Registered
Joined
·
109 Posts
Discussion Starter · #5 ·
the hiss goes away if the inputs or outputs are unplugged, it is the level setting of the unit that is giving me the trouble I believe.

I will try again with various levels of input/output. If I set the input really low and the output higher will that be ok, or should I just set both the input and output low? So far that is the only way I get a clean signal if both are lower than zero. I tried it yesterday with the input a little lower and the output a little higher and still got some hiss if I remember correctly. I'm just trying to get the same clean signal I used to have before I installed this unit... arrrgh...

I'll report back on my findings in a bit...
 

·
Registered
Joined
·
12,053 Posts
the hiss goes away if the inputs or outputs are unplugged, it is the level setting of the unit that is giving me the trouble I believe.
if the hiss goes away when you unplug the input RCAs, then you know the noise is not internal to the DQS, it is amplifiying noise from the HU. remember, that thing has 12bd input AND 12db output amplification. any little noise will make itself apparent with that kind of gain.
I will try again with various levels of input/output. If I set the input really low and the output higher will that be ok, or should I just set both the input and output low?
it will be fine as long as you dont drive the output higher than the setting on the amplifier. as you are finding out, you move one gain and it effects everything down the line, lol.
So far that is the only way I get a clean signal if both are lower than zero. I tried it yesterday with the input a little lower and the output a little higher and still got some hiss if I remember correctly. I'm just trying to get the same clean signal I used to have before I installed this unit... arrrgh...

I'll report back on my findings in a bit...
if you have to set it low/low and that gives you the signal/noise you need, then there is nothing wrong with it. one thing I havent asked. how many volts are the outputs on your HU?
 

·
Registered
Joined
·
109 Posts
Discussion Starter · #7 ·
I guess what I'm banging my head about is that before I put this eq in I didn't have that noise and now I do. I used the same interconnects and just added on to them with 3ft pieces to the eq, then additional 1.5ft rca's the amps. I was super careful not to run any power or ground close to them whatsoever.

The HU is a kenwood excelon kdc-x895 and "supposedley" 4v unbalanced pre-outs x3 I also have the HU internal amp set to the off position which kenwood claims to be the cleanest possible signal you can get when using it's pre-outs.

I just got done tinkering around a bit more and found if I barely turn the input gain up (slightly more than full counterclockwise) and the output gain up slightly more than that I'm getting the cleanest signal I've been able to achieve thus far.

My next step will be to move the power/ground someplace else, I ran out of time to mess with it further tonight. I still think that could be the culprit. I have it basically piggybacked to my sub amp where the power/ground/remote go into it... Maybe I'll try straight off my distribution block. Maybe somehow my sub amp is "back feeding" some sort of signal into the eq? If that is the case then moving it to the distribution block won't change anything because it's just a foot away from the amp. (just thinking out loud here)

For some people this tiny level of "hiss" may be acceptable and liveable but since I had such a great clean signal before adding the eq and ZERO noise it is more of a mission now to get rid of it! I just know myself and it will bug the crap out of me if I hear it during really quiet passages.
 

·
Registered
Joined
·
12,053 Posts
I understand your frustration, but the input and outputs of that device are gains. 12DB each. Total of more than 100x power gain. If you don't need to turn them up, don't. Use your amplifier gains instead

Sent from my Motorola Electrify using Tapatalk 2
 
1 - 8 of 8 Posts
Top