12' Taurus SHO SONY Audio Updgrade - Stereo HISS

[sho_spot]

Hi Guys,

First time posting.  I could use some assistance/comments on my recent audio install.

I have done many mono sub installs along with head unit upgrades in countless vehicles.  I am very much a DIY.
I tackled this project, it being my most involved.

I also wanted to post this for others who are wanting to improve the sound quality of their Ford Taurus SHO w/Sony Premium & Navigation.
I am in traveling sales, and basically live in my car i required and wanted to keep all the factory HU options.  Audio over the years has become very important to me.  I like a completely stock look with all upgrades hidden behind carpet, hood, etc...

This system sounds awesome to me, I like more treble for those curious on the Alpine amp I think it lends itself better to higher frequencies in my opinion. I actually need to dial it back a bit, it gets ear bleeding loud w/clarity.

My build components:

Audio Controls LC81
Alpine PDX-V9 w/rux knob
Polk Audio  DB5251 (front door & A-pillar components) roughly 100rms
Polk Audio  DB571  (rear co-axials) roughly 60rms
KnuConcept 4AWG Wiring Kit

I tuned the system using the voltage method with 1khz for speakers and 50hz for sub.  I used plug wiring diagrams I pulled off this forum for wiring up the LC8i.  I am summing all the inputs in my PDX for the sub out.
For anyone looking to mount the LC81 I simply used some large threaded rod spacers with self tappers, no need for a custom plate.
Currently have small 8" type R alpine, but I have a 10" type r sitting in the basement I will soon throw in a sealed enclosure back there.
Center speakers were left powered off the Sony Amp, as well as the factory deck subs.

I am not a person who likes a ton of bass, and I didn't want to modify the rear deck.  Once I get this hiss figured out I will button everything back up with the carpet and you should not even be able to tell anything is going on the trunk...with the exception of the sub.

One of the main questions I have is that I have a very faint HISS coming through the speakers whether audio is on or off.  It is extremely faint but I sit enough parked in my car with the radio off that it is bothersome.  I can not tell if it gets louder with volume.  My thought is it is a grounding issue.

I removed paint with a simple shark bite wheel and have the ground secured to the inner steel wheel well.
What can I do to eliminate this?  Is there a factory grounding point in the trunk?

I welcome comments/questions/improvements.

See photos.  I do not have photos of installing the speakers, they were pretty simple.  I do have some pictures of my modified tweeter install.

Thanks in advance!!!!

[ZSHO]

Do you have navi ,if so try turning it off,and see what happens,and would install a noise filter?

[Lanson]

Hard to say.  RCAs look a little disheveled, maybe tidy them up and keep them out of the path of current.  You'll have to go back to basics.  EXPECT some hiss, no matter what.  There's too many items in the chain.

[themetalmaster]

There is a ground point on the top of the parcel shelf. There is also one behind the leather trim panel on the sides of the rear passenger seat. I feel like I'm not describing that well. If you sit in the rear passenger seat behind the driver, the panel you need to remove will be the one touching your left shoulder. Its pretty easy to take off, you start by pushing it away from the door at the bottom, that should allow you to slip the plastic anchor off the stud and pull it out.

You could also try grounding to the metal plate that the Sony amp is mounted to. It is attached to metal studs connecting to the chassis.

If you un-mount your amplifier and shine a flashlight in the compartment behind it you might be able to see it.

I'm not an expert, but if the hiss doesn't increase with volume it would make sense that the hiss is being introduced post amplification. If there was a hiss pre amplification it would get louder as you increased the volume.

You could try setting the gains on the amp and LCI when the head unit is at 50% volume. See if that does anything.

[sho_spot]

Thanks guys, i will let you know when I find the time in the near future to perform the following checklist:

1. Tidy up the wires, include as much separation as possible, maybe introduce some cable sheathing.

2. Locate the grounding points and see if I can land the ground on one of those.  FYI I landed the ground initially on the amp frame bolt and the noise/hiss was unbearable had to change and land it on the inner wheel well as mentioned.

You could also try grounding to the metal plate that the Sony amp is mounted to. It is attached to metal studs connecting to the chassis.


3.  Try some different tuning methods to eliminate hiss, playing with gain settings and LC8i settings, turning off Navi as a test.

4.  Look into some ground isolators/noise filters??  I am not familiar with these do they go between the RCAs from LOC LC8i to Amp??  I will do more googling.

Your fast responses are awesome!

[sho_spot]

Okay guys, I landed the ground onto the ground points inside the left shoulder rest in the back seat.  Thanks themetalmaster.
I cleaned up the wiring and put good spacing between RCAs and speaker wires. Tried tuning, playing with volumes, gains, etc... no avail.
I will try a ground isolator next....but this hiss is so minimal I may end up living with it... not sure yet.

Currently the SHO is in the shop getting some chrome tail light fixing.

[dalum]

A ground loop occurs when there is a difference of resistance to ground between equipment.  Once you link multiple electronics that have their own power source with rca's they try to equalize the grounds through them.  Since this flow of electricity over the rca's is in the audio path you can hear it.  A lot of amps/processors ground through the chassis so when you mount them to metal you can get a ground loop too. 


Unplug the rca's at the amp. 
Make sure the amp is on and check for noise.
     If noise: remove the amp from the metal and check for noise.
          If noise: problem is in amp.
          If no noise: isolate amp chassis from metal while mounted.
     If no noise: Amp checks ok - reconnect rca's to amp.
Unplug audio input connectors from AudioControl, make sure Audiocontrol and amp are powered on.
     If noise: remove AudioControl from metal.
          If noise: ground differential between AudioControl and amp.
               -Relocate grounds.  Possibly ground processor to amp's ground and not to amp input.
          If no noise: isolate Audiocontrol chassis from metal while mounted.
     If no noise: processor to amp chain is ok.
          Plug audio inputs back into AudioControl.
               If noise returns ground problem between amp+AudioControl and factory system.
                    Relocate grounds. 
                         -Try moving ground for factory amp to same ground point used by Audiocontrol+amp.

Ideally all of your grounds would come from 1 point in the car and star out from there with equal distance and gauge wire to each device.  This is impossible, especially with the multiple units in the factory system alone.  If you can't fix the problem you want the audio level at its highest without clipping pre noise injection.  This gives you the best signal to noise ratio.  So say the problem is with the AudioControl unit.  You would want your "head unit" at its highest pre clipping volume so you can turn the gain on your amp down effectively turning down the noise while still having the same level of signal coming from the speakers.

The noise isolators break the electrical grounds and use coils to transfer the signal.  I would avoid them if possible.

[goblues38]

One of the main questions I have is that I have a very faint HISS coming through the speakers whether audio is on or off.  It is extremely faint but I sit enough parked in my car with the radio off that it is bothersome.  I can not tell if it gets louder with volume.  My thought is it is a grounding issue.

I removed paint with a simple shark bite wheel and have the ground secured to the inner steel wheel well.
What can I do to eliminate this?  Is there a factory grounding point in the trunk?

In your second picture.  Is that the final set up?  Looking at that, you have the gains on the Audio Control device set pretty high.  I know with the stock head unit on these cars you want to try and hit your max volume when the "dial" up front for volume is at say 75%.  You do this to take away the stock bass management, where it removes low frequencies at high volume to reduce clipping.

As far as the ground.  Back in the day when i was an installer / designer.  The seat belt anchor was always the preferred ground in point.  That ties directly into the car frame.  Where you are in the wheel well, you may have glued welds or seams that may not be the best ground.

[Lanson]

I agree with ALL of that. 

[sho_spot]

Okay guys it'd been awhile.   Thank you for all your help. I finally have it dialed in.  Here is what I found out. Long story short I had the LC8I turned up WAY to high.  Currently I have the LC8I set to roughly half and my gains on my alpine power amp set extremely low, like 2nd notch. I basically arrived at these setting by level matching to my front and rear center speaker which I left hooked up to the stock sony amp.  Now I have ZERO hiss in my system and it sounds killer. Previous to my change in setting my amp was overheating and going into protection mode, after the changes I no longer get that.  I did apply some heat sinks on the outside of the amp because the carpet was insulating the heat.

Also I did tie the ground to behind the seat belt on driver side rear seat shoulder pad.

Overall thanks again and I am extremely pleased and have received many compliments on how well the system sounds...and best part is everything is hidden and nobody can even tell anything aftermarket had been installed. 

[SHOdded]

Nothing left to do but sit back & enjoy the ride

[Lanson]

Okay guys it'd been awhile.   Thank you for all your help. I finally have it dialed in.  Here is what I found out. Long story short I had the LC8I turned up WAY to high.  Currently I have the LC8I set to roughly half and my gains on my alpine power amp set extremely low, like 2nd notch. I basically arrived at these setting by level matching to my front and rear center speaker which I left hooked up to the stock sony amp.  Now I have ZERO hiss in my system and it sounds killer. Previous to my change in setting my amp was overheating and going into protection mode, after the changes I no longer get that.  I did apply some heat sinks on the outside of the amp because the carpet was insulating the heat.

Also I did tie the ground to behind the seat belt on driver side rear seat shoulder pad.

Overall thanks again and I am extremely pleased and have received many compliments on how well the system sounds...and best part is everything is hidden and nobody can even tell anything aftermarket had been installed. 

Fantastic!

Install is everything.