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Scosche SLC4 Line Output Converter

Convert speaker connections to line-level preamp connections in mobile audio applications

165 Reviews | 10 questions - 12 answers

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Overview

Our take on the Scosche SLC4 Line Output Converter

So you're trying to connect an amplifier without speaker-level inputs to a car stereo that doesn't have preamp outputs? It can be done, but you'll need a line output converter to make it happen. The SLC4 from Scosche can handle up to four speaker-level inputs and four RCA outputs — enough for a 4-channel amp or a multi-amp setup.

Scosche SLC4 Line Output Converter

So you're trying to connect an amplifier without speaker-level inputs to a car stereo that doesn't have preamp outputs? It can be done, but you'll need a line output converter to make it happen. The SLC4 from Scosche can handle up to four speaker-level inputs and four RCA outputs — enough for a 4-channel amp or a multi-amp setup.

Connect the speaker leads from your car stereo to the SLC4. It reduces the incoming speaker-level signals so that outgoing signals are compatible with the preamp inputs on your amplifier. You will then need to use two RCA patch cords (not included) to make the connections to your amp.

The SLC4 features adjustable gain settings on each channel, and it's compatible with any car stereo. Dimensions: 4-7/8"W x 1-3/16"H x 2-3/4"D. Warranty: 90 days.

Note: Most vehicles will require additional installation parts — please identify your vehicle if you haven’t done so. You can also call an Advisor for more information.

works great

Anonymous, Marietta, GA

What's in the Box:

  • Line output adapter with attached plastic screwdriver
  • Instructions
Reviews

Scosche SLC4 Line Output Converter Reviews

Average Customer Review(s):

(165 Reviews)
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Product Research

Features

Overview: This is a versatile adapter that allows for multiple applications. If your receiver doesn't have preamp outputs and you want to connect it to an amp that doesn't have speaker level inputs, this adapter can be used to convert you receiver's speaker level outputs into preamp outputs. With this adapter, you can hook either a 2-channel or 4-channel amplifier to this adapter, and not lose fader control. This adapter also allows you to add an aftermarket receiver to either a common ground audio system in your vehicle, or an audio system that has factory amplifiers (like many of the Premium, JBL, and Bose audio systems). There are gain controls for both the line outputs and the factory amp inputs. Which gain controls you use depends on your application.

Note: There is a plastic screwdriver that is physically attached to the adapter, and must be broken off to use. It is used to adjust gain controls and screw down the speaker terminals.

Speaker-Level-to-Line Level Conversion: The adapter can convert car stereo speaker outputs to RCA outputs so an external 2 or 4 channel amplifier can be added to a car audio system. There are line output controls that allow you to adjust the output level going into your amplifier(s). The adapter can handle up to 50 watts (RMS) / 100 watts (Peak) of speaker level input.

Interface with Factory Amplified Systems: This adapter allows the matching and installation of an aftermarket receiver with most factory amplified systems like the Premium/JBL/Bose systems.

Subwoofer Application: The adapter will allow for the integration of a subwoofer or subwoofers to nearly any audio system. There are line output controls that you can use to adjust the output level going into your amplifier(s).

Common Ground Audio Systems: With this adapter, you can add an aftermarket receiver to a common ground system in your vehicle without having to run new speaker wires. There are factory amp gain controls that you can use to adjust the input levels.

Common Ground/Factory Amp/Line Out Switch: Depending on how you are using the adapter will depend on what position the switch will be in. If you are adding a new receiver to a common ground system, then the switch is put into the "Common Ground" position. If you are adding the receiver to a factory system that uses Premium, JBL, and or Bose, then the switch is put into the Factory Amp position. You can also add an external amp to a receiver that does not have line outputs; in this case the switch will be in the "Line Out" position. There are factory amp gain controls that you can use to adjust the input levels.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Accessories
Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

recommended [ Michael  Jun 16, 2017 ]
very helpful [ Craig  Jun 14, 2017 ]
per crutchfield I need to convert in this car [ yoke  Jun 04, 2017 ]
easy fit [ William  May 27, 2017 ]
Necessary accessory [ Arthur  May 10, 2017 ]
cost effective solution [ Andrew  Apr 25, 2017 ]
Part of installation kit for my car [ David  Apr 16, 2017 ]
Need [ Robert  Apr 15, 2017 ]
recommend by Crutchfield advisor to get ride of a static problem. fixed about 95% of the problem. However when you adjust the gains on the amp a little bit lower it takes someone with extremely good hearing to hear the 5%. I don't hear it anymore. [ Michael  Apr 13, 2017 ]
maintain all functions [ Marlen  Apr 10, 2017 ]
Used to connect factory amp to aftermarket radio. [ michael  Apr 06, 2017 ]
It takes some patience(And a few choice words) to install, but if you are replacing a factory head unit with a powered aftermarket unit, you may want to pick this up. Especially if you have Bose or other premium factory audio. Aftermarket head units put out extra power compared to factory units, this device will help protect your system. Worth the time and headache spent installing, but I dont exactly look forward to installing another one. [ Lucinda  Mar 21, 2017 ]
I need it [ Anthony  Mar 17, 2017 ]
To get the best quality out of my new stereo. [ Guest  Mar 17, 2017 ]
This came with the head unit I purchased. I won't be it because I will be running RCA interconnects between the head unit and amp. [ michael  Mar 07, 2017 ]
required [ Joe  Mar 06, 2017 ]
need it for car [ kenneth  Feb 07, 2017 ]
single din cd player does not have 4v front and rear line level outputs so the speaker level outputs need to be converted [ jason  Jan 30, 2017 ]
Honestly it came with the system, will see if I need it. [ Jason  Jan 26, 2017 ]
It was free as well. [ james  Jan 23, 2017 ]
No crazy splicing [ Ty  Jan 22, 2017 ]
i want to keep my factory amp and ensure maxium voltage being feed to the amp for audio clarity [ Brentt  Jan 06, 2017 ]
Easy to setup on my Nissan Titan. [ Samuel  Jan 04, 2017 ]
said i needed it [ JOHN  Dec 30, 2016 ]
Husband asked for it. [ Inara  Dec 13, 2016 ]
Because the system that's in my vehicle [ Yvonne  Dec 05, 2016 ]
my car has a factory amp and in order to use it i needed this converter [ Justo  Nov 29, 2016 ]
need to use the factory Bose system [ Timothy  Nov 23, 2016 ]
might need it [ Eric  Nov 17, 2016 ]
Because it came in the installation package. [ Miguel  Nov 15, 2016 ]
Because of the purpose it serves. [ shane  Oct 17, 2016 ]
I don't think I need this because my radio uses pre-amp outputs already so this may be still in the box after installation. [ david  Oct 15, 2016 ]
When I add an amplifier it will make the install that much easier to hook up [ Glenn  Oct 04, 2016 ]
I was advised by the Crutchfield support team that this could fix an issue with white noise hiss I've been experiencing since I installed my aftermarket stereo that could be related to my stock amplifier. [ Michael  Oct 03, 2016 ]
Not sure [ Roland  Sep 11, 2016 ]
required for installation- offered in a package at the end of my purchase [ Michaella  Sep 04, 2016 ]
It was a recommendation from online purchase [ T  Sep 01, 2016 ]
This was recommended with my car radio purchase. [ Antonio  Aug 30, 2016 ]
recommended by expert [ C  Aug 28, 2016 ]
I needed to adjust output to match a factory amp...this worked perfectly, but it's a little bulky to fit behind the dash. [ TODD  Aug 28, 2016 ]
I picked these items because your tech told me they were compatible with my 2008 Kia Sorrento, hopefully there will be no problems once I receive and install. Thanks [ Karen  Aug 07, 2016 ]
not needed [ Rupinder  Jul 15, 2016 ]
I don't even know what this is. [ Nicholas  Jul 12, 2016 ]
Required if you have a factory amp that you still want to use till you replace it [ Marc  Jul 04, 2016 ]
Recommended [ Raul  Jun 27, 2016 ]
Great addition. [ Itay  Jun 02, 2016 ]
part of installation package [ Vincent  May 10, 2016 ]
Required in order to convert to RCA in my 2013 Nissan Altima [ Harry  May 09, 2016 ]
perfect to match with OEM power amplifier [ Rafael  May 05, 2016 ]
When switching from MB oem radio to another, I'd rather have and not need than the reverse. [ Richard  May 03, 2016 ]
To use my factory amp [ HERIBERTO  Apr 21, 2016 ]
I didn't & not sure it will be needed - using pre-amp outputs on Clarion FZ105. [ MR JERRY  Apr 18, 2016 ]
packaged by crutchfield [ Terry  Apr 12, 2016 ]
To use my factory Bose amp and sub [ Graham F.  Mar 13, 2016 ]
I TRUST YOU THAT IT WORKS [ hector  Feb 10, 2016 ]
it fit my car [ Ethan  Feb 01, 2016 ]
Because the advisor said it would be compatible with my car :) I knew it would work:) [ Isaac  Jan 28, 2016 ]
To connect aftermarket radio with only two outputs to a 2008 Nissan Rogue with a Bose factory amplifier system. [ John  Jan 23, 2016 ]
This worked great for tapping into the speaker lines before the factory amp and feeding my Alpine amps for my JL Audio 10" Subs. [ titanium man  Jan 18, 2016 ]
this reduces the incoming speaker level [ MICHELLE  Jan 01, 2016 ]
This output converter is part of the Crutchfield kit for installing my car sound system. I bought my first Crutchfield car stereo (also a Pioneer) in the late 1970's. It was all done on the phone. Even back then Crutchfield knew what was needed for your car. I figure they still do, so whatever is in the recommended install kit I get it. [ Gary  Dec 16, 2015 ]
Necessary to ensure compatibility between new radio and factory wiring harness and equipment [ Andrew  Dec 05, 2015 ]

10 questions already asked

Tech Support is included with your purchase from Crutchfield, feel free to contact our Tech Support team. They can walk you through the connections to see if this may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. [ Kenny  May 27, 2017 ]  Staff
I did use it on a E46 model BMW,it work fine after it was install but it was a pain to make it fit on the BMW hopefully yi have moi room, gooo luck [ William  Jun 22, 2016 ]
If you tune the gains right, then maybe. I had a similar problem and buying higher resistance speakers did the trick. Also note that this thing is huge and will not fit behind most headunits. [ JORDAN  Apr 26, 2016 ]
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your factory controls. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you. [ Kenny  Mar 05, 2016 ]  Staff
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your factory system. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you. [ Jeff  Dec 01, 2015 ]  Staff
The Scosche SLC4 is a versatile adapter that allows for multiple applications. If your receiver doesn't have preamp outputs and you want to connect it to an amp that doesn't have speaker level inputs, this adapter can be used to convert you receiver's speaker level outputs into preamp outputs. With this adapter, you can hook either a 2-channel or 4-channel amplifier to your factory radio and not lose fader control. This adapter also allows you to add an aftermarket receiver to either a common ground audio system in your vehicle, or an audio system that has factory amplifiers (like many of the Premium, JBL, and Bose audio systems). There are gain controls for both the line outputs and the factory amp inputs. Which gain controls you use depends on your application. [ Larry  Oct 30, 2015 ]  Staff
I forwarded your question to an Advisor and they responded with the following: Please give an advisor a call at 888.955.6000 so we can identify your vehicle and the best way to integrate your amplifier into your vehicle. [ Krissy  Sep 16, 2015 ]  Staff
Yes [ GABRIEL P  Jul 06, 2015 ]
Each channel on this converter has an adjustment down inside. Use an eyeglass screwdriver flat head to adjust the level to an acceptable volume. I suggest turning all the levels all the way back then turning the volume up to the loudest you would ever use. At this point you can adjust the level to the loudest your speakers handle cleanly. [ CHAD E  Jul 05, 2015 ]
Where would I be able to online chat with them? [ Justin  Mar 05, 2014 ]
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your factory system. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you. [ Krissy  Mar 02, 2014 ]  Staff
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