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Adding an Aftermarket Amp(s)

Gonz

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here you go

1297F60CC-80C1-431A-ABA6-098822D0FF7B.webp
If you flip those arrows in the pic, that's the post I grounded my amp to. The one with the plastic cap on it that holds another couple wires.
 

sandor.g

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So, I have installed my PAC AP-CH41.R2, the Alpine KTP-445U and the Alpine PWE-S8. I have a Mustang kit that is technically the same as the Wrangler PSS-23WRA kit, except the T-harness (which I replaced with the PAC harness anyhow) and the brackets (that I ordered already) but I guess I am repeating myself. Without installing my new speakers it already sounds so much better (I have the 7" Uconnect and the Non-Amp system). I was pleased to hear the improvement. I was very upset though to hear the D.MN HISS! If I go to 4V signals the hiss is less noticeable, but it's still there.
Instead of wiring the Positive lead under the cabin, I have penetrated the firewall as Sting_NC_USA suggested (even after removing the front passenger flare, it took the most time of the entire installation.
If I disconnect the the PAC outputs one by one, the hiss goes away, so it's definitely the PAC that is giving me trouble, not the amp. I'll try moving the ground tomorrow, just to make sure I've tried everything, but it is starting to worry me, that I am in the same shoes as Biconia was before.
 

Biconia

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So, I have installed my PAC AP-CH41.R2, the Alpine KTP-445U and the Alpine PWE-S8. I have a Mustang kit that is technically the same as the Wrangler PSS-23WRA kit, except the T-harness (which I replaced with the PAC harness anyhow) and the brackets (that I ordered already) but I guess I am repeating myself. Without installing my new speakers it already sounds so much better (I have the 7" Uconnect and the Non-Amp system). I was pleased to hear the improvement. I was very upset though to hear the D.MN HISS! If I go to 4V signals the hiss is less noticeable, but it's still there.
Instead of wiring the Positive lead under the cabin, I have penetrated the firewall as Sting_NC_USA suggested (even after removing the front passenger flare, it took the most time of the entire installation.
If I disconnect the the PAC outputs one by one, the hiss goes away, so it's definitely the PAC that is giving me trouble, not the amp. I'll try moving the ground tomorrow, just to make sure I've tried everything, but it is starting to worry me, that I am in the same shoes as Biconia was before.
yes grounding will not fix that HISS things i tried moving the ground here and there , also tried from battery , tried changing ground from 8 Gauge to 0 nothing think i tried everything from the world to diagnose that thing out and i couldn't find the answer if you get that HISS please update us , also when u disconnect the PAC yes his is gone so i guess...
 
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Sting_NC_USA

Sting_NC_USA

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So, I have installed my PAC AP-CH41.R2, the Alpine KTP-445U and the Alpine PWE-S8. I have a Mustang kit that is technically the same as the Wrangler PSS-23WRA kit, except the T-harness (which I replaced with the PAC harness anyhow) and the brackets (that I ordered already) but I guess I am repeating myself. Without installing my new speakers it already sounds so much better (I have the 7" Uconnect and the Non-Amp system). I was pleased to hear the improvement. I was very upset though to hear the D.MN HISS! If I go to 4V signals the hiss is less noticeable, but it's still there.
Instead of wiring the Positive lead under the cabin, I have penetrated the firewall as Sting_NC_USA suggested (even after removing the front passenger flare, it took the most time of the entire installation.
If I disconnect the the PAC outputs one by one, the hiss goes away, so it's definitely the PAC that is giving me trouble, not the amp. I'll try moving the ground tomorrow, just to make sure I've tried everything, but it is starting to worry me, that I am in the same shoes as Biconia was before.
Have you tried this from the troubleshooting section of the manual:
  • Hiss at high amp gain - Set feature DIP switch 2 to the on (down) position to lower the output voltage of the AP4 to 4v. If you still hear the hiss, lower your amp gains until the hiss is gone.
 

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Goosed

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Have you tried this from the troubleshooting section of the manual:
  • Hiss at high amp gain - Set feature DIP switch 2 to the on (down) position to lower the output voltage of the AP4 to 4v. If you still hear the hiss, lower your amp gains until the hiss is gone.
What do you think is causing this hiss for some but not all?
 

Biconia

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PAC need to fix this issues asap or there already on work , firmware will come up soon i guess ?
 

sandor.g

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Have you tried this from the troubleshooting section of the manual:
  • Hiss at high amp gain - Set feature DIP switch 2 to the on (down) position to lower the output voltage of the AP4 to 4v. If you still hear the hiss, lower your amp gains until the hiss is gone.
Yeah, I have already gone done to 4V signals and it does get better. But it’s still there.
I will try moving stuff a bit and call PAC too.
 

sandor.g

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PAC need to fix this issues asap or there already on work , firmware will come up soon i guess ?
Hey, could you check what your PAC’s build/version number is? We nay have the same defective build
 

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Biconia

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or if you want to jump FIX86
FIX86 compare to PAC its totally another world , no joke trust me my 4 channel amp are not adjusted yet ( Gain , Freq are all the way down )
so clean and crisp the sound :)
 
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Sting_NC_USA

Sting_NC_USA

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What do you think is causing this hiss for some but not all?
It's really hard to say. I'm using the resistor method with the JL Audio Fix86, though I've installed the PAC for others with no issues (yet!).

Since a calibration is involved, I'd recommend anyone with a Hiss conduct a full reset of the PAC. Before re-calibrating, make sure the Bass, Treble, Balance and Fader are in their neutral positions prior to the reset and re-calibration, and also ensure Bass Boost and that "adjust volume for speed" setting are off.

As shared above, grounding is very important, and so is running the RCA Cables in a different area than the power wires. I also recommend logging into PAC's software to disable their EQ. And lastly, I've seen tons of "gain" abuse, meaning folks are turning the gains on their amps up way to high. Some amps have recommendations for voltage testing to ensure the gains are within tolerance.

While discussed previously, the PAC does an OK job of flattening the pre-EQ'd sound. The JL Fix86, and other DSP's, do an Excellent job of flattening/conditioning the stock signal. It seems the calibration on some PAC devices simply isn't handling the process very well, and it could be a firmware issue, a DIP switch issue, a grounding issue or something not yet identified. If after trying the above, the hiss remains, the best bet would be to call PAC's support team directly. With the issues seen here (and through searching online), I may just have to call them myself. If I do, I'll post the results.

PS: As a reminder, we really need to be using the R.2 (Revision 2) edition of the PAC.

EDIT: I've sent a full write-up to PAC, and will share anything I hear. Stay tuned...
 
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ToPar9

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Sorry for late post here is my PAC info
Well crap ... That is the same version I have as well. I really need this to work. I am hoping to not shell out another 200 on the Fix86.
I was hoping to spend less than 420 bucks on my speaker upgrade in all. :CWL::CWL:
Ah, well ... we shall wait and see.

**From their website, latest version below**
Firmware Download, Version 2.1.3.15 (Released on July 15th, 2019)
Nothing new has been released in almost a year.
As soon as I get my install done, I will post an update on here.
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