If you want to add an aftermarket amplifier or subwoofer to your factory car stereo, a line output converter (LOC) is the essential bridge. It takes the high-level speaker signal from your stock radio and converts it into low-level RCA outputs your new amp can use.
This guide reviews ten of the best LOCs on the market, from budget-friendly passive models to advanced active units with bass restoration. You will learn what to look for and which one fits your specific needs.
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Kicker 46KISLOC2 K-Series Stereo Line-Output Converter w/Remote Turn-On Output
Best forSimple amp integration with remote trigger
- Built-in remote turn-on
- Accepts high input
ConsiderNo bass restoration
AudioControl LC1i Active 2-Channel Line Driver & Line Output Converter for …
Best forModern cars with factory amps
- Load selection switches
- Line driver boosts signal
ConsiderPricier than passive LOCs
Scosche LOC2SL Line Output Converter with Remote Control Knob – 2CH High/Lo…
Best forDash-mounted bass control
- Remote bass knob
- Easy installation
ConsiderPassive design
CT Sounds CT-LC2 2-Channel Premium Line-Out Converter with BassLift
Best forRestoring factory bass roll-off
- BassLift technology
- Dual outputs
ConsiderNo remote control
AudioControl LC2i 2-Channel Line Output Converter with AccuBASS for Adding …
Best forSpace-saving install with bass correction
- AccuBASS technology
- Compact design
ConsiderNo remote bass knob
Skar Audio SKE2LOC 2-Channel Active Line Output Converter
Best forVersatile turn-on options
- Selectable turn-on modes
- Adjustable bass and main
ConsiderRequires power and ground
Skar Audio SKAR2CH-LOC 2-Channel Speaker Wire to RCA Line-Out Converter
Best forUniversal compatibility with smart radios
- Wide compatibility
- Flat frequency response
ConsiderNo bass restoration
Recoil LOC4 4 Channel Speaker Cable to RCA Adjustable Line Output Converter
Best forMulti-channel systems with noise isolation
- 4-channel output
- Remote turn-on
ConsiderLarger size
Scosche LOC80 Line Output Converter – 2 Channel High/Low RCA Converter Car …
Best forBudget-conscious basic upgrades
- Affordable price
- Easy installation
ConsiderNo remote control
NuIth Car Audio Speaker Wire to RCA Line Output Converter, 2-Channel High t…
Best forQuick and easy subwoofer addition
- Gain adjustment
- Easy installation
ConsiderNo remote turn-on
Kicker 46KISLOC2 – Compact Stereo LOC with Remote Turn-On
The Kicker 46KISLOC2 is a stereo line-output converter that adds an amplifier to nearly any factory radio. It automatically converts the speaker signal into both RCA and a powerful 100 milli-amp, 12-volt remote turn-on output. This means you do not need a separate remote wire from your head unit, simplifying installation.
It accepts up to 55 watts (16 volts) of input signal, making it compatible with most stock systems. The KISLOC2 delivers true sonic accuracy at any volume, preserving sparkling highs and thunderous lows. Its compact size fits easily behind the dash or under a seat.
- Built-in remote turn-on
- Accepts high input
- Compact design
- No bass restoration
- Limited to 2 channels
AudioControl LC1i – Active Line Driver with Load Switching
The AudioControl LC1i is an active 2-channel line output converter that upgrades your factory stereo while keeping it. It converts speaker-level signals up to 400W (40V) per channel into high-quality pre-amp outputs. The onboard load selection switches let modern factory amplifiers detect speaker loads and continue passing audio seamlessly.
Its built-in line driver boosts weak factory radio signals, providing optimum output for downstream amps and subwoofers. You can also control subwoofer levels from the driver’s seat with the optional ACR-1 dash knob remote. This unit is perfect for late-model vehicles with complex audio systems.
- Load selection switches
- Line driver boosts signal
- Optional remote bass knob
- Pricier than passive LOCs
- Requires power connection
Scosche LOC2SL – Compact LOC with Remote Control Knob
Brand: Scosche
A practical choice for simple subwoofer additions with remote control.
The Scosche LOC2SL is a 2-channel high/low RCA converter that includes a remote control knob for adjusting bass levels from your dash. It is designed for easy installation, making it a go-to solution for connecting a subwoofer amp to a factory stereo. The compact and durable design ensures it fits in tight spaces.
This line level converter delivers crisp and clear sound quality, ensuring no loss of audio fidelity. Its unmatched versatility means it works with a wide range of car audio systems. You can fine-tune the bass without reaching for the amp, enhancing your driving experience.
- Remote bass knob
- Easy installation
- Compact build
- Passive design
- No bass restoration
CT Sounds CT-LC2 – Premium LOC with BassLift Technology
The CT Sounds CT-LC2 is a 2-channel premium line-out converter that features BassLift technology to restore factory bass roll-off. It converts high-level speaker signals into low-level RCA outputs, and also provides a full-range main output and a low-pass bass output for subwoofers. This dual output design gives you flexibility in system setup.
BassLift compensates for the bass reduction that many factory radios apply at higher volumes, ensuring you get consistent low-end performance. The converter is built with quality components for reliable operation. It is an excellent upgrade for those who want to keep their factory head unit but crave more bass.
- BassLift technology
- Dual outputs
- Compensates for bass roll-off
- No remote control
- May require tuning
AudioControl LC2i – Compact LOC with AccuBASS
The AudioControl LC2i is a 2-channel line output converter with AccuBASS processing that corrects bass roll-off as you increase volume on the factory radio. It converts speaker-level signals up to 400W per channel to high-quality pre-amp outputs. The compact slim chassis with integrated mounting brackets makes installation quick and easy without taking up extra space.
You retain important factory features like volume and steering wheel controls, because the LC2i works with your OEM system. It is designed to maximize your bass output while keeping the stock look. This is a favorite among car audio enthusiasts for its performance and size.
- AccuBASS technology
- Compact design
- Retains factory controls
- No remote bass knob
- Higher price point
Skar Audio SKE2LOC – Active LOC with Selectable Turn-On
The Skar Audio SKE2LOC is an active 2-channel line output converter with selectable turn-on options: DC offset signal sense, audio sense, or remote 12V output. This flexibility ensures reliable turn-on with any factory radio. It also features fully adjustable bass and main channel controls, allowing you to fine-tune the signal.
With a frequency response of 21Hz to 30kHz and an operating voltage of 13.8 volts DC, it delivers clean, full-range audio. The active design boosts weak signals for better amplifier performance. It is a solid choice for those who want control over their signal path.
- Selectable turn-on modes
- Adjustable bass and main
- Wide frequency response
- Requires power and ground
- No remote knob
Skar Audio SKAR2CH-LOC – Passive LOC with Wide Compatibility
The Skar Audio SKAR2CH-LOC is a 2-channel speaker wire to RCA line-out converter compatible with OEM, aftermarket, and smart radios. It accepts up to 55 watts (16 volts) of input signal, making it robust for most factory systems. The flat 20Hz to 20kHz frequency range ensures accurate sound at all volume levels.
It applies a 60-ohm load to each channel, which helps circumvent open-circuit protection in some factory amps. This makes it a safe choice for modern vehicles with complex audio electronics. The passive design is simple to install and does not require external power.
- Wide compatibility
- Flat frequency response
- Prevents open-circuit issues
- No bass restoration
- No remote turn-on
Recoil LOC4 – 4-Channel LOC with Remote Turn-On
The Recoil LOC4 is a 4-channel speaker cable to RCA line output converter designed for adding an amplifier to a factory radio. It converts the radio’s speaker level output to low-level RCA inputs for your amp. It also provides an amplifier remote turn-on output, simplifying the wiring process.
Utilizing an audio transformer for noise isolation, the LOC4 ensures clean signal transfer without alternator whine or interference. This is especially beneficial for systems with multiple channels. The adjustable input levels allow you to match the converter to your factory radio’s output.
- 4-channel output
- Remote turn-on
- Transformer isolation
- Larger size
- No bass restoration
Scosche LOC80 – Budget-Friendly 2-Channel LOC
The Scosche LOC80 is a 2-channel high/low RCA converter that offers unmatched versatility for a wide range of car audio systems. It is designed for easy installation, making it a go-to solution for connecting a subwoofer amp to a factory stereo. The compact and durable design ensures it fits in tight spaces.
This line level converter delivers crisp and clear sound quality, ensuring no loss of audio fidelity. It is ideal for boosting the bass of your factory system without replacing the head unit. The LOC80 is a budget-friendly option that does not compromise on performance.
- Affordable price
- Easy installation
- Reliable performance
- No remote control
- Passive design
NuIth LOC – Simple 2-Channel Converter with Gain Adjustment
The NuIth car audio speaker wire to RCA line output converter allows you to add a 2-channel or mono amplifier or subwoofer to your existing factory or aftermarket stereo. It converts the high-level speaker output to RCA cables, improving sound quality. The level gain adjustment lets you tune the bass without pulling over to adjust the amplifier.
This converter is easy to install, using the speaker wires from your factory radio to provide the signal. It is a practical solution for those who want to enhance their audio system without replacing the head unit. The compact size fits discreetly behind the dash.
- Gain adjustment
- Easy installation
- Compact size
- No remote turn-on
- Basic build
Buyer’s Guide: What to Consider
Selecting the right line output converter depends on your vehicle’s audio system and your goals. Consider factors like channel count, active vs passive design, and special features like bass restoration or remote control. This guide highlights key points to help you make an informed decision.
- Channel Count: Choose a 2-channel LOC for a single subwoofer or a 4-channel for powering front and rear speakers. Match the number of channels to your amplifier's inputs for proper signal distribution.
- Active vs Passive: Active LOCs have built-in circuitry to boost weak signals and often include features like bass restoration. Passive LOCs are simpler, cheaper, but may not correct signal issues. Consider your factory radio's output strength.
- Bass Restoration: Many factory radios reduce bass at higher volumes to protect speakers. Features like AccuBASS or BassLift compensate for this roll-off, ensuring consistent low-end performance. If you love bass, prioritize this feature.
- Remote Turn-On: Some LOCs provide a remote turn-on output that signals your amplifier to power up. This eliminates the need to run a separate remote wire from the head unit, simplifying installation and ensuring reliable amp activation.
- Input Power Handling: Check the maximum input wattage or voltage the LOC can handle. Most factory radios output between 10-20 watts, but some high-powered systems may exceed that. Choose a converter that can safely accept your radio's signal without distortion.
Conclusion
Choosing the best line output converter comes down to your specific needs and budget. For simple, reliable performance, the Kicker 46KISLOC2 or Scosche LOC2SL are excellent choices. If you have a modern car with factory amp issues, the AudioControl LC1i or LC2i provide advanced features like load switching and bass restoration.
For bass enthusiasts, the CT Sounds CT-LC2 with BassLift is a standout. Whatever you pick, ensure it matches your system’s requirements. All ten converters reviewed here are quality options that will help you add an amp or sub to your factory stereo with confidence.
Erica Steven is the founder and lead writer of WorstBrands, a site dedicated to providing honest and trustworthy reviews about outdoor gear and fashion products.
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