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Scosche SLC4 Line Output Converter
Convert speaker connections to line-level preamp connections in mobile audio applications
Item # 142SLC4 | MFR # SLC4
$19.99 Earn up to 20 Rewards points
Our take on the Scosche SLC4 Line Output Converter by Crutchfield's Tim Sprinkle
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.
Scosche SLC4 Line Output Converter Reviews
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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.
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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
1 answer My newly installed aftermarket head unit on my 2005 Pontiac vibe is way too loud. Volume 0 sounds more like volume 5 and includes a constant static. Am I right to assume I can connect this between the vehicles harness and my head unit harness to lower the gain from the factory amp? [ Sam P May 27, 2017 ]
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
2 answers I have a pioneer avh-4100nex in my 2010 camaro that has a factory amp. right now, the schosche install kit has the speaker level outputs from the pioneer going to the factory amp, and is too loud. Will this allow me to use the rca preamp outputs on the pioneer instead? [ JAMES Jul 04, 2015 ]
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 ]
I didn't use this adaptor bc I removed the entire Bose system out of my Z. I recommend you do the same bc the Bose system is junk! You will be happy you did! [ JEREMY May 31, 2014 ]
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