Adding an aftermarket amplifier to a factory sound system often feels like a puzzle. A line-output converter, or LOC, acts as the bridge between your stock head unit and new audio gear. Without this component, integrating subwoofers into a modern vehicle is nearly impossible.
A quality LOC keeps your signal clean while preventing noise. I would look for models that offer bass restoration and handle high voltage. These features ensure your music stays punchy and clear, even when you turn up the volume.
List of Best Car Audio Loc
| Image | Product | Score | Link |
|---|---|---|---|
 | AudioControl LC2i PRO 2-Channel Line Output Converter with A 🏆 Editor’s Pick | 9.5/10 |
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 | AccuBASS 2-Ch Line Out Converter Kit – LC2iPro Processor and | 9.3/10 |
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 | AudioControl LC1i 2-Channel Car Audio Line Output Converter 🥈 Runner-Up | 9.2/10 |
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 | AudioControl LC2i 2-Channel Line Output Converter with AccuB | 8.9/10 |
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 | AudioControl LC2i 2-Channel Line Out Converter with Dash Rem | 8.7/10 |
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 | CT Sounds CT-LC2 2-Channel Premium Line-Out Converter with B | 8.5/10 |
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 | Skar Audio SKE2LOC 2-Channel Active Line Output Converter | 8.3/10 |
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 | Scosche LOC2SL Line Output Converter with Remote Control Kno | 7.9/10 |
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 | Kicker 46KISLOC2 K-Series Stereo Line-Output Converter w/Rem 🏆 Editor’s Pick | 7.8/10 |
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 | Skar Audio SKAR2CH-LOC 2-Channel Speaker Wire to RCA Line-Ou 💵 Budget Pick | 7.5/10 |
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📋 How We Evaluated
Evaluations focus on signal clarity, voltage handling, and ease of installation. Performance testing considers how well each unit restores bass roll-off and maintains factory features.
Detailed Reviews
AudioControl LC2i PRO 2-Channel Line Output Converter with A🏆 Editor’s Pick
| Technology | AccuBASS |
| Remote | Included ACR-1 |
| Indicators | LED Clipping |
| Channels | 2 |
What We Found
The AudioControl LC2i PRO takes the successful LC2i formula and adds significant upgrades. It includes the ACR-1 dash remote for convenient subwoofer control from the driver’s seat. A built-in LED clipping indicator ensures you set your gains perfectly without distortion. The AccuBASS system is improved for even smoother frequency response.
It handles high-power OEM signals up to 400 watts with ease. The unit features selectable turn-on modes including GTO signal sensing. It is built to last with high-quality internal components and a durable chassis. This converter provides the most control and diagnostic feedback in the lineup.
It represents the best balance of performance, ease of use, and signal quality for modern car audio systems.
💬 My Take
I would choose this if you want to dial in your system perfectly from the driver seat.
Who It’s For
This is for the serious enthusiast who wants the best possible bass output. It is perfect for those who want to tune their system accurately using the included clipping indicator and remote.
✅ Pros
- Includes essential remote level control.
- Clipping indicator prevents distortion damage.
- Superior bass restoration performance.
❌ Cons
- More expensive than standard models.
- Requires careful initial gain setup.
- Larger than entry-level converters.
AccuBASS 2-Ch Line Out Converter Kit – LC2iPro Processor and
| Included | LC2i PRO + 17ft RCA |
| Technology | AccuBASS |
| Cable | Oxygen Free Copper |
| Channels | 2 |
What We Found
This kit includes the LC2i PRO processor along with high-quality 17-foot oxygen-free copper RCA cables. It is designed for users who want an all-in-one package for their subwoofer installation. The LC2i PRO itself provides industry-leading bass restoration and signal processing.
The included cables ensure minimal signal loss and interference during transmission. This package is ideal for those who want to avoid the hassle of buying components separately. The kit ensures that all parts are matched for optimal performance. It is a convenient and reliable solution for upgrading factory audio systems.
The build quality of both the processor and the cables is exceptional, ensuring long-term satisfaction for the user.
💬 My Take
I would choose this kit to take the guesswork out of building your audio system.
Who It’s For
This is perfect for the DIY installer who wants everything in one box. It is great for those who want to ensure their signal path is clean and high-quality.
✅ Pros
- Includes high-quality cables in the box.
- LC2i PRO is a top-tier processor.
- Convenient, all-in-one package for installers.
❌ Cons
- Higher cost due to included accessories.
- Cables may be longer than needed for some builds.
- Overkill for those who already have cables.
AudioControl LC1i 2-Channel Car Audio Line Output Converter 🥈 Runner-Up
| Max Input | 400 Watts |
| Load Selection | 20/60/20k Ohms |
| Turn-on | GTO/Remote |
| Channels | 2 |
What We Found
The AudioControl LC1i acts as a powerful line driver and converter. It accepts high-voltage signals up to 400 watts per channel, making it compatible with premium factory systems. The onboard load selection switches prevent common issues with modern vehicle amplifiers. It features selectable GTO signal sensing for automatic power-on convenience.
The build quality is exceptional, featuring durable components designed for harsh automotive environments. It effectively boosts weak factory signals to a clean, usable level for downstream gear. The optional dash knob adds physical volume control for subwoofers. This unit bridges the gap between stock radios and high-performance aftermarket processors perfectly.
It offers the flexibility needed for complex system builds.
💬 My Take
I would shortlist this for professional-grade integration where keeping factory features is a priority.
Who It’s For
This unit is ideal for owners of modern vehicles with complex factory amplification. It serves those who need to boost weak signals while maintaining factory integration features. It is perfect for users who want to add subwoofers without sacrificing control.
✅ Pros
- Handles very high input voltages.
- Load selection switches ensure compatibility.
- Excellent signal boosting capability.
❌ Cons
- Remote knob sold separately.
- Requires more space than basic converters.
- Higher price point than simple units.
AudioControl LC2i 2-Channel Line Output Converter with AccuB
| Technology | AccuBASS |
| Max Input | 400 Watts |
| Control | Variable/Fixed |
| Dimensions | 5.4 x 3.25 x 1.5 inches |
What We Found
The AudioControl LC2i remains a staple in the car audio industry. It features the signature AccuBASS technology that restores low-frequency output lost at high volumes. The compact chassis includes integrated mounting brackets for a clean install. It handles up to 400 watts per channel, covering almost any factory system.
You can easily adjust the main and sub levels with discrete controls on the unit. It retains critical factory features like volume and steering wheel controls. The build quality is robust and reliable, consistent with the brand’s reputation.
While it lacks some of the pro-series features, it performs its core function exceptionally well. It remains a top choice for those focused specifically on adding subwoofers.
💬 My Take
I consider this the standard for bass restoration, as it is consistently reliable.
Who It’s For
This product is perfect for anyone wanting to add a subwoofer while keeping their factory head unit. It is ideal for those who notice their bass dropping off as they turn up the volume.
✅ Pros
- AccuBASS effectively restores lost low frequencies.
- Compact footprint eases installation.
- Retains factory radio functionality.
❌ Cons
- Lacks the clipping indicator found on Pro models.
- Does not retain fader control.
- Mounting brackets add to overall length.
AudioControl LC2i 2-Channel Line Out Converter with Dash Rem
| Technology | AccuBASS |
| Remote | Included |
| Max Input | 400 Watts |
| Outputs | Fixed/Variable |
What We Found
This variation of the AudioControl LC2i includes the essential dash remote for convenient volume adjustment. It maintains the core strengths of the LC2i, including 400-watt input handling and AccuBASS restoration. The unit is designed specifically for those adding subwoofers to factory systems.
It retains steering wheel controls and factory volume functionality perfectly. The build is sturdy and compact, fitting into most vehicle interiors with ease. It offers separate fixed and variable outputs for flexible system design. While it lacks the clipping indicator of the Pro model, it provides the same core performance.
It is a reliable choice for anyone who wants high-quality sound with dedicated subwoofer control.
💬 My Take
I think this is a great middle-ground option that balances performance and convenience.
Who It’s For
This is for the enthusiast who wants the benefits of AccuBASS and the convenience of a remote knob. It is perfect for those who want to tune their bass on the fly.
✅ Pros
- AccuBASS provides excellent bass recovery.
- Dash remote allows for real-time adjustments.
- Retains all important factory radio features.
❌ Cons
- No clipping indicator for gain setup.
- Does not support fader control.
- Standard model lacks advanced Pro features.
CT Sounds CT-LC2 2-Channel Premium Line-Out Converter with B
| Technology | BassLift |
| Outputs | Full-Range & Low-Pass |
| Channels | 2 |
| Manual | 34-Page Guide |
What We Found
The CT Sounds CT-LC2 features proprietary BassLift technology to compensate for factory bass roll-off. It provides both full-range main outputs and low-pass subwoofer outputs. This unit effectively converts high-level signals into clean RCA inputs for your amplifiers. It comes with a detailed manual that simplifies the installation process.
The build quality is professional and robust, suitable for permanent placement. It offers a balanced approach to signal conversion and bass enhancement. The unit is designed to work with a wide range of modern factory radios. It effectively solves the problem of thin bass response in stock systems.
Users will appreciate the clear output and reliable signal processing.
💬 My Take
I would recommend this for DIYers who appreciate clear instructions and integrated bass enhancement.
Who It’s For
This is for the user who wants better bass without buying a standalone processor. It is perfect for those who need clear instructions and a reliable, all-in-one solution.
✅ Pros
- BassLift technology improves low-end response.
- Includes both full-range and low-pass outputs.
- Extensive manual makes installation easy.
❌ Cons
- Larger footprint than simple converters.
- Requires more careful installation wiring.
- Less common than market-leading brands.
Skar Audio SKE2LOC 2-Channel Active Line Output Converter
| Control | Adjustable Bass/Main |
| Turn-on | DC/Audio/Remote |
| Frequency | 21Hz-30kHz |
| Remote | Included |
What We Found
The Skar Audio SKE2LOC is an active converter that offers extensive control over your signal. It features selectable turn-on options, including audio sense and remote 12V output. The unit includes adjustable bass and main channel controls for precise tuning. It supports a wide frequency response from 21Hz to 30kHz.
The build quality is rugged, designed for longevity in automotive conditions. It comes with a remote level control for convenient volume adjustments from the driver’s seat. This active unit is highly versatile and fits into many different system configurations. It provides a clean, powerful signal for aftermarket amplifiers.
Users will appreciate the flexibility provided by the multiple turn-on modes and adjustable output levels.
💬 My Take
I would pick this if you enjoy customizing your sound through an active unit.
Who It’s For
This unit is perfect for the user who wants maximum control over their audio signal. It is great for those who need flexible turn-on options for their specific vehicle.
✅ Pros
- Highly adjustable output levels.
- Multiple turn-on options for flexibility.
- Includes remote level control.
❌ Cons
- More complex to tune than passive units.
- Requires active power connections.
- Larger housing requires more install space.
Scosche LOC2SL Line Output Converter with Remote Control Kno
| Control | Remote Knob Included |
| Channels | 2 |
| Build | Compact |
| Compatibility | Universal |
What We Found
The Scosche LOC2SL is a versatile converter featuring an included remote control knob. It is designed for seamless integration between factory stereos and aftermarket amplifiers. The compact, durable design fits into tight spaces, making it ideal for custom installs. It minimizes signal interference to deliver clean, high-fidelity sound.
The unit is compatible with a wide range of car audio systems. It provides a straightforward method for boosting audio performance without complex rewiring. The build quality is solid, reflecting the brand’s experience in audio accessories. It works well for subwoofer applications where user control is desired.
The installation process is quick and simple for most vehicle types.
💬 My Take
I find this to be a handy, all-in-one solution that simplifies the subwoofer addition process.
Who It’s For
This is perfect for users who want to add a subwoofer and need remote volume control. It is great for those who value ease of installation and a compact form factor.
✅ Pros
- Includes remote control knob for convenience.
- Compact design is easy to install.
- Good compatibility with various vehicles.
❌ Cons
- Lacks advanced bass restoration features.
- Build quality is functional but basic.
- Not suited for high-power factory systems.
Kicker 46KISLOC2 K-Series Stereo Line-Output Converter w/Rem🏆 Editor’s Pick
| Input Handling | 55 Watts |
| Signal Sensing | DC Offset |
| Output | RCA |
| Channels | 2 |
What We Found
The Kicker 46KISLOC2 is a reliable, entry-level option. Its compact design hides easily behind most dashboards. It handles up to 55 watts, which covers most factory radios. The remote turn-on feature simplifies wiring by using DC offset to trigger your amplifier. It focuses on pure conversion without extra features.
The build feels sturdy enough for permanent installation, and it maintains a flat frequency response.
💬 My Take
I would pick this for basic setups where simplicity matters more than advanced tuning.
Who It’s For
This converter suits enthusiasts who need a simple, reliable way to add a subwoofer to a factory radio. It works best for users on a budget who do not require advanced signal processing or remote level control. Installation is straightforward, making it a great choice for beginners.
✅ Pros
- Compact design fits easily into tight dashboard spaces.
- Simple installation process for beginners.
- Reliable remote turn-on signal generation.
❌ Cons
- Lacks advanced bass restoration technology.
- No remote volume control included.
- Limited to basic signal conversion.
Skar Audio SKAR2CH-LOC 2-Channel Speaker Wire to RCA Line-Ou💵 Budget Pick
| Input | 55 Watts |
| Output | 8 Volts RMS |
| Frequency | 20Hz-20kHz |
| Load | 60 Ohms |
What We Found
The Skar Audio SKAR2CH-LOC is a straightforward and effective solution for basic needs. It provides a flat frequency response from 20Hz to 20kHz, ensuring no coloring of the sound. The unit accepts up to 55 watts of input signal.
A 60-ohm load is applied to each channel to prevent factory protection circuits from triggering. It produces clean RCA outputs up to 8 volts RMS. The build is compact, allowing for easy mounting behind head units or under dashes.
It lacks advanced features like bass restoration, but it excels in pure signal conversion. This unit is reliable for users who just need to get a signal to their amplifier. It is simple to install and works immediately upon connection.
💬 My Take
I would use this when you need an affordable, clean signal conversion without extra features.
Who It’s For
This is ideal for budget-conscious installers who need a simple converter. It works best for standard speaker-to-RCA tasks where no advanced signal processing or bass restoration is required.
✅ Pros
- Very affordable price point.
- Flat frequency response ensures accuracy.
- Prevents factory system protection errors.
❌ Cons
- No bass restoration technology.
- Lacks remote level control.
- Basic feature set only.
What to Look For Before Buying
Choosing the right converter depends on your vehicle and your audio goals. You should consider the power levels of your factory radio and the features you need. Quality matters when converting signals to ensure your music stays clear.
Check Signal Compatibility and Power Handling
Check the maximum voltage your factory system produces. Most converters work with standard units, but premium systems often need higher voltage capacity.
Value Bass Restoration Features
Factory radios often lower bass at high volumes to protect speakers. Look for active bass restoration to fix this and get a punchier sound.
Rating Integration and Control Options
Think about whether you need a remote level knob for your subwoofer. Active converters often provide better tuning options and easier signal sensing.
Verify Installation Requirements
Measure the space available behind your dashboard or under your seats. Some converters are compact, while others require more room for wiring. Check if the unit includes mounting hardware for a secure fit. A clean install prevents rattles and protects your equipment.
Frequently Asked Questions
Do I really need an active LOC?
Active units provide a cleaner signal and better tuning than passive ones. They are essential if your factory system has a weak output.
Will an LOC change my factory volume controls?
No, a quality converter keeps your factory volume and steering wheel controls working exactly as they did before.
Can I install an LOC myself?
Yes, many converters are made for straightforward DIY work. You mainly need to tap into speaker wires and provide power.
What is the benefit of a clipping indicator?
A clipping indicator helps you set your amplifier gains safely. It prevents distortion and protects your speakers from damage.
Does the cable quality matter?
Yes, cable quality matters. Oxygen-free copper cables reduce resistance and interference, ensuring your audio arrives at the amplifier without losing detail.
🎯 Final Verdict
For the best overall performance, the AudioControl LC2i PRO is my top choice. Its combination of AccuBASS, remote control, and clipping indicators makes it the most capable tool for factory integration. If you want a budget-friendly alternative, the Skar Audio SKAR2CH-LOC is a clean, simple option.
Both will significantly improve your car audio experience.
James Dimento is a Chief-in-Editor of SoundUnify. He is a headphone enthusiast and creative writer passionate about audio technology. He has three years of experience writing about headphones and sound quality and is responsible for creating reviews and taking care of all administration.