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Discussion Starter #1
Hello All,

I've been a longtime visitor to this forum, but never needed to post before now. So here's my dilemma:

I have a 2012 Acura TSX Wagon. Just had my entire system redone:
  • Memphis Audio 4-Channel amp installed to power front and rear door speakers
  • Sundown 6.5" component speakers installed in front doors
  • Focal 6.5" coaxial speakers installed in rear doors
  • Mono Amp installed to power subwoofer
  • Sundown 12" sub with box installed
  • Audiocontrol LC8i installed to feed signal to all of the channels
Overall, the audio quality sounds fantastic. My issue is that even with the volume control at 1, there is a hissing/static noise signal coming through. It's not a consistent hum, but more of a hiss that varies and cracks a little bit. This happens on all inputs (Radio, CD, Aux, Bluetooth) and turning the volume up increases the noise. This happens whether the car is running or not, and revving the engine has no effect on it. It's fine when the music is blasting, but if there is any quiet, say like listening to a podcast, then it's really noticeable.

The car audio shop did some adjustments to the gains and tweeters that helped a little bit, but it's still there. They basically told me that I just have to live with it. Is that true or is there something I can do about this?

I would really appreciate any help at all. Thank you.
 

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Discussion Starter #2
Oh, and all of the amplifiers, crossovers and the Audiocontrol LC8i are installed in in the back compartment where my emergency flat tire fix is located. They are all within about 6" or so of each other. Not sure if that makes a difference, but thought it was worth mentioning.
 

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I have the same vehicle base model. Is it Navi or base model head unit? The base is a balance signal so there may be a jumper inside of the Audiocontrol control LC8
 

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Discussion Starter #4 (Edited)
I have the same vehicle base model. Is it Navi or base model head unit? The base is a balance signal so there may be a jumper inside of the Audiocontrol control LC8
It's the base model head unit, doesn't have the tech package. Sorry for my ignorance, but what's a jumper?
 

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No, you don't have to live with it. Hopefully, you bought the equipment from them. I had a shop do me that way years ago with alternator whine and I just camped out in front of the bay door until they fixed it. turned out to be a careless ground but they told me to just go get new plugs and wires blah blah blah and that it was the car. Also suggested I change the rca (that they installed and sold me). I was about 16 and I didn't know much but I knew it was not like that when I took it in and they installed an amp. After thinking about it I went up there early on Sat morning and parked in front of the bay door and took the keys out and just sat there. I told them I would move when it was fixed. after a few words were exchanged they opened the door and I drove in and it was fixed within about 10 minutes.
 

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Definitely sounds like a ground issue. I'm dealing with the same thing now. It started after adding a dsp and another amp. Still working on trouble shooting. Will post my solve when its resolved.
 

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If it is quiet with the engine off then that is a helpful clue.
Is it the same in terms of noise, or different?
 

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He said same, running or not.
Could be relationship between head volume, the Audiocontrol setup, and amp gains.
 

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He said same, running or not.
Could be relationship between head volume, the Audiocontrol setup, and amp gains.
^thanks^ that is two posts today which I did not read ;)

The volume knob should have no effect if it was noise in the amp so the only way it could be amp gains is if we're one of those new jobs that squelches if the input is low.

It must be coming to the amp.
Probably listening to if it is coming into the DSP would be a good first step.
It is either coming into it or being created in the DSP.
If the amps RCAs are disconnected then there should be no noise and hiss coming out of the speakers unless the amp is generating it.
 

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I don't see where he stated anything about a DSP. There is an LC8i. It is a line driver with signal restoration (whatever they call it). I think if not set up correctly, they can do more harm than good. I know I took out my LC7i and ordered a DSP, because I just couldn't get clean sound from stock head to it and out of it.
 

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Got it !

The theory is still the same...
In either it is noisy going into the LC8i or coming out of it.

Both sides should be able to be tested...
1) out is likely able to go into headphones if there are RCSs.
2) The in part might be assumed to be Ok if the headunit was fine before "upgrading" to the LC8? But it could be harder to test that side.
 

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My theory is the LC8i isn't set up correctly or adjusted sufficiently and isn't outputting enough voltage for the amp. Also, the headunit must be adjusted to output max clean volume to the next component down the line, the LC8i, so that it, in turn, can be adjusted properly, and then the amp gain can be adjusted properly.
 

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It’s clearly a tuning issue, if he’s getting significant audio at volume 1 then that sounds like all gains are way too high
 

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It's the base model head unit, doesn't have the tech package. Sorry for my ignorance, but what's a jumper?
If the signal is captured directly from the HU (preferred) and before the OEM amp then there is a movable jumper/resisitor pin under the LC8i cover that should be put in the "balanced" mode. It is truly a low voltage balanced signal that comes out of the HU and not your standard high level source that comes from a post amplifier signal. I did my wagon both ways and the pre-amp method yielded the best results by far. If that doesn't work than we go down the rabbit hole...
 

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Discussion Starter #15 (Edited)
Thank you all so much for the replies. I agree that it is something with the LC8i. I'll try to move it to the "balanced" mode. I found a thread on another forum with some people having the exact same issue with similar setups and all of them said they were able to remedy the problem by switching their amps input level from high to low. Does that sound right? If the LC8i is putting out the low voltage balanced signal maybe moving the amp to low matches it?

I should note that my amp does not have an input switch so I'm not able to test this theory.
 

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Thank you all so much for the replies. I agree that it is something with the LC8i. I'll try to move it to the "balanced" mode. I found a thread on another forum with some people having the exact same issue with similar setups and all of them said they were able to remedy the problem by switching their amps input level from high to low. Does that sound right? If the LC8i is putting out the low voltage balanced signal maybe moving the amp to low matches it?

I should note that my amp does not have an input switch so I'm not able to test this theory.
Why ask?
Just go and try it, and then we can all know.
 

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Thank you all so much for the replies. I agree that it is something with the LC8i. I'll try to move it to the "balanced" mode. I found a thread on another forum with some people having the exact same issue with similar setups and all of them said they were able to remedy the problem by switching their amps input level from high to low. Does that sound right? If the LC8i is putting out the low voltage balanced signal maybe moving the amp to low matches it?

I should note that my amp does not have an input switch so I'm not able to test this theory.
I think that it may go into the lc8i as "balanced" but that's not necessarily what you see at the output stage. My understanding for that unit is that it has the ability to take two different types of input signals, thus the internal jumper pins, and output a low level signal to your amplifier's input stage. My experience was different, I was able to solder RCA plugs on the head units leads and plug them directly into my amplifier's inputs that accept a balanced signal. It worked flawlessly and yielded no distortion or noise floor that was Audible. In fact, it was eerily quiet in between songs but I needed more processing features so eventually I went after market with the Kenwood 9903s.
 

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The Memphis amp I have doesn't have an input switch so I'm not able to try out that solution without getting a new amp.
I meant the LC8i "balanced" switch.
(f it has one like Wagoneer suggested,)
 

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Discussion Starter #20
I meant the LC8i "balanced" switch.
(f it has one like Wagoneer suggested,)
Oh definitely. I'm a little apprehensive about jumping under the hood of the LC8i because I have no clue what I'm doing, but I'm going to try to switch that tonight or tomorrow. I'll report my findings.
 
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