Lincoln LS Stereo

[Rhyan]

Hello all,
I have a 2004 Lincoln Ls with the sport package and the 12 speaker sound system. Im not 100% who makes the system but i know that it is the factory system in the car. I listen to a variety of music and latley i have noticed that in the speakers in the doors there is a lot of distortion. I cant tell if the problem with the speakers or with the amp. It sounds like its more an issue with the amp rather than the speakers because i had a similar problem with another car of mine. I would like to fix the problem and keep what i can with the factory system (ie speakers and head unit). Does anyone know where i can find a replacement factory amp (new or slightly used) id really like to get this problem fixed.
Thanks for any advice.

[shorod]

Welcome to the forum!

I'd say it's more likely that a distortion issue is due to the speakers rather than the amp, but before replacing either of them there are a few things you can check. Of course if you have an oscilloscope you can identify the cause really quickly. Assuming you do not have access to a scope, I'd suggest you try adjusting the fader and balance to each f the corners of the car and see if the amount of distortion sounds the same. I'd suggest you use a CD with a dynamic song for this so you're starting with a good source. If you find it is only one or two corners that seem to have distortion, I'd be more prone to suspect the speakers. If however you find that all four corners have similar distortion issues, then the issue is likely either the amp or the signal to the amp (head unit). Door panels are relatively easy to remove on the 2004 so you could remove one and plug a replacement speaker in to confirm the distortion remains before digging for the amp or head unit.

Unfortunately, identifying if the issue is head unit or amplifier will be pretty tricky without access to an oscilloscope or function generator.

As for sources of the amp and head unit, you're looking at one of the auction sites or an auto salvage place. You'll also want to pull the units and the get part numbers off them to make sure you get a compatible item. As you are aware, there are various different levels of audio system available for the LS, so with different amplifiers, etc.

-Rod

[joegr]

Since you have the 12 speaker system, there is no external amp for the door speakers. That amplifier is internal to the head unit. (There are two external amps, one for the center channel speakers in the console, and another for the sub-woofers under the rear package tray.)

The only configuration with an external amp for the door speakers is the THX navigation option. With that option, the door speakers' amplifier is in the trunk on the side wall behind the trim. The THX nav is a 10 speaker system. (no center console speakers)

[shorod]

Joegr is right. The good news is this should make determining if it's a speaker issue or head unit issue easier. If you remove the head unit and connect a known good 4 ohm speaker right to the speaker output and it sounds distorted, you know the head unit is the source of the issues. If the speaker sounds fine, you're looking at either a wiring or speaker issue.

Can you tell if the distortion seems to just be from the door speakers or if it's also from the center image speakers in the console?

-Rod

[coopillio1]

Does anyone know the exact location of the external amplifier on a 2004 lincoln ls with the thx sound system, and what is the wiring color code?

[shorod]

There's more than one amplifier in the factory system. The main radio amplifier is located at the left hand (driver's side) rear of the trunk. It's mounted on the side behind the "carpet" trim. There's a separate subwoofer amplifier that is mounted on the underside of the package tray/rear deck between the left and right subwoofers. Keep in mind that the "Enable" signals are likely to be a logic level rather than a 12V turn on signal. What I've seen in the past is they are 5V, so you'll either need to use a relay, solid state relay, or transistor circuit to turn an aftermarket amp on if that's what you're trying to accomplish.

Subwoofer amp pinouts


Radio amp pinouts:



-Rod

[coopillio1]

which amplifier would you suggest I run my line out converter to. I am just trying to hook up a amp and subs? I want to retain the factory radio.

[shorod]

If your aftermarket amplifier has high voltage line inputs, why not use the subwoofer signals that feed the factory subwoofer amplifier? These may be differential, but you should still be able to make them work. If you decide you don't want to do that for whatever reason then it seems the obvious answer would be to use the subwoofer outputs from the factory subwoofer amplifier. That may limit how much you can alter the crossover points for your aftermarket subs though.

-Rod

[coopillio1]

How would a person be able to know if the aftermarket amp has high voltage inputs? and when you were talking about the car having a 5volt instead of 12volt and having to run a relay, was that talking about how I have to run a remote wire to get the amp to turn on?

[shorod]

The specifications for the amplifier should list what the pre-amp input level range is. My recall is standard used to be up to something like 1V, but recently more and more manufacturers have been going up to as much as 4V. I haven't measured the pre-amp levels for the factory sub amp, but I doubt they are higher than 4V.

Yes regarding the 5V enable, that is in reference to the aftermarket remote turn on. If you try to just run the enable line from the factory amplifier to your aftermarket amplifier it probably won't work until you do some level shifting or run a separate switched remote turn on wire. One nice thing about sticking with the enable line and level shifting though is then when/if you mute the factory stereo it would also mute the subwoofer amp.

-Rod

[coopillio1]

Thanks rod, I am very great full for your help, just one more question. How would i use the subwoofer signals to run audio to the amp like you were saying, I am new to the whole running a sub/amp while still retaining the factory radio deal. Do I still use the line out converter in this? I am just doing research right now. I plan on doing the install this week for a friend. Again thank you so much for your expertise. Als0 my amp says it has speaker level inputs so I assume that is high voltage, right?.... I checked and the amp does have the high voltage hook up but I dont have the 4 pin harness in order to use that application on this install. So would you say the line out converter to the sub woofer + and - would be ok?

[tkswan]

Originally Posted by joegr

Since you have the 12 speaker system, there is no external amp for the door speakers. That amplifier is internal to the head unit. (There are two external amps, one for the center channel speakers in the console, and another for the sub-woofers under the rear package tray.)

The only configuration with an external amp for the door speakers is the THX navigation option. With that option, the door speakers' amplifier is in the trunk on the side wall behind the trim. The THX nav is a 10 speaker system. (no center console speakers)

on a side note, have you seen my post called Looking for Joegr?

[shorod]

Originally Posted by coopillio1

How would i use the subwoofer signals to run audio to the amp like you were saying. Do I still use the line out converter in this?Als0 my amp says it has speaker level inputs so I assume that is high voltage, right?.... I checked and the amp does have the high voltage hook up but I dont have the 4 pin harness in order to use that application on this install. So would you say the line out converter to the sub woofer + and - would be ok?

I'm start by wiring pins 7 and 8 of C466a to the RCA inputs of the aftermarket subwoofer amp. When in mono mode, it's typical that the amp would only use the left channel if I recall correction. But since I don't know what amp you plan to use, I'm not sure if your amp has a mono mode or not. If using that input causes problems, then you could use the speaker level inputs of the aftermarket amp with the wires that normally go to the factory subwoofers. What I don't like about that approach is you are amplifying the subwoofer signals with the factory amplifier only to run them in to the aftermarket amp.

Are you able to purchase a replacement connector for the speaker level inputs? If you need to go speaker level to the aftermarket amp, using the amplifier's internal line level converter may be better than what you would end up with using an external converter.

-Rod