If you want to upgrade your car sound system for more powerful sound output, including louder volume and booming bass, then you need to invest in an external amplifier. However, if you’re using a factory stereo, you might find it hard to connect an amplifier. Basically, an amplifier is connected to a preamp output. Sadly, most factory stereos don’t have a preamp output. That’s where a line out converter (LOC) comes in handy. A LOC converts high-level signals from a stereo receiver into low-level signals for amplification by an external amplifier. However, you need to invest in the best line out converter for efficient signal conversion.
Essentially, most stereo receivers output signals of up to 400 watts. On the other hand, amplifiers can safely handle an input signal of about 6 volts on average. If you connect an amplifier to a higher signal voltage than what it can safely handle, it may burn out. Thus, it’s advisable to invest in a LOC to ensure your amplifier is only fed with an input signal whose voltage is safe for the amplifier to handle.
There’re many LOC models available in the market today. Thus, choosing the best one for your car sound system can be a challenging task. That’s why we’ve prepared this buyer’s guide and reviews to assist you in making the right choice.
Quick Comparison Table
Top 6 Line out Converter Reviews
Line out converters are available in different models. They mainly differ in output levels and input/output channels. Thus, you need to make your choice wisely to ensure that the LOC you choose is suitable for your car audio system. Here’re the top 6 line out converters available today.
1. Kicker KISLOC
Kicker manufactures some of the best LOCs available today. Their Kicker KISLOC is preferred by many car owners for good reasons. If you’re searching for a 2-channel LOC, Kicker KISLOC would be one of the best options to choose from.
- Silver tinned OFC wire- The Kicker KISLOC line out converter comes with silver tinned OFC wire. This type of wire allows for enhanced bass response. It also allows for clear signals for enhanced sound output. As a result, you’ll enjoy clear sound output across all frequencies.
- High efficiency- This LOC comes with 2 speaker channels with the ability of taking an input of up to 50 watts and outputting a signal of up to 8 volts. Considering its small size, that’s a huge range of signal conversion. It outputs a top-quality signal without consuming a lot of power.
- Huge frequency range- The LOC supports a high-frequency response of between 20Hz to 20KHz. Thus, it’s able to convert all frequencies including highs, midrange, and lows.
- Discreet installation- Another remarkable feature of this LOC is its micro-sized design. You can easily install it in tight locations for more discreet installation. Furthermore, you only need wire cutters and soldering iron to install it. This makes it easy to install.
- Dual-mold connectors- It comes with dual-mold K-Grip connectors that offer a tight, solid connection. Thus, you’ll enjoy smooth sound without cutting out on and off even when driving off-road.
- High signal output.
- Compact design.
- Split pin RCA.
- Pocket-friendly price range.
- Micro surface mount.
- Limited versatility.
- Creates humming noise in some cases.
If your factory radio has an open-circuit protection, then this Kicker KISLOC is the right option for your car audio system. It’s also perfect for use with monoblock amplifiers.
2. AudioControl LC2i
AudioControl LC2i is one of the best line out converters available today. If you want high-quality signals from a factory receiver to an external amp, then look no further. It’s made for those who like premium sound systems in their cars. It’s made to output high-quality preamplifier signals without interfering with the factory controls.
- Patented AccuBASS technology- This LOC boasts of having patented AccuBASS technology from AudioControl. The AccuBASS technology is featured in the circuitry. It works by reversing any reduction in the bass level when turning up the volume in a factory radio. Thus, you can enjoy booming and loud bass from your factory system.
- Remote control- Looking for a convenient LOC? You’ll appreciate the optional remote control featured in this LOC. The remote control is mountable on the dash for enhanced convenience. You can take advantage of the remote control to adjust the subwoofer channel while driving.
- High-voltage output- Premium sound systems often require being fed with high-powdered sound signals. This LOC comes with 2 channel inputs for connecting signals of 400 watts at most. It converts the signals and outputs a powerful signal of 9.5 volts at most. Its powerful signal output allows a high-performance amplifier to operate optimally.
- Active input- This LOC comes with a 2-channel processor, featuring an active input circuit. Thus, it’s able to take in speaker-level inputs from factory radios or factory amplifiers to output preamp signals for use with aftermarket amps or processors.
- Low distortion- Another area where this LOC is unmatchable is its low distortion. Its distortion level is under 0.01% on average. Thus, you’ll enjoy high-quality sound across all sound frequencies.
- Convenient operation.
- Patented GTO signal sensing technology.
- Compact design.
- Variable and fixed outputs.
- Level controls.
- Quite pricey.
- Doesn’t come with instructions for installation.
The AudioControl LC2i line out converter is specially designed for use with premium quality sound systems and amplifiers that can handle high-powered preamplifier signals. If you’re willing to pay a little more for a premium-quality LOC, then this is the best option for you.
3. PAC SNI-35 Variable LOC
The PAC SNI-35 Variable LOC offers an extra set of preamplifier outputs from a factory receiver that only has a single set. It’s designed as a variable LOC with advanced adjustment options.
- Variable signal adjustment- One of the key features that makes it one of the best line out converters is that it supports factory radios with a signal of 2 to 40 watts RMS per channel. It outputs a linear frequency of between 20 Hz to 10 kHz.
- Advanced transformer- The transformer integrated into the LOC features an advanced technology that isolates the input circuit from the output circuit. As a result, it prevents the occurrence of ground loop problems. Consequently, it produces noiseless signals for clear sound.
- Near universal fit- Another top feature of this LOC is its near-universal fit. It’s compatible with most factory radios. Thus, you won’t struggle to find a compatible LOC for your car. Chances are that this LOC will be suitable for your car factory radio.
- Power and ground wires- The LOC comes with a set of wires comprising of a pair of positive and negative wires for connecting the speaker level and an extra brown wire for use as a ground wire to eliminate any hiss or hum noise. This further enhances the quality of the output signal.
- Passive design- Another top feature that this LOC boasts about is its passive design. It doesn’t require any external power source to operate. You only need to hook it to the factory radio and an amplifier or subwoofer.
- Extremely affordable.
- Phase adjusted.
- Noise isolation.
- Adjustable gain.
- Marked speaker wire for easier identification of the positive and negative terminals.
- Not the best for powerful systems.
- Tends to heat up when the gain is turned up.
The PAC SNI-35 Variable LOC is specially designed with affordability in mind. It’s ideal for anyone who wants an efficient LOC but is working with a very tight budget.
4. DS18 V5HL
The DS18 V5HL is yet another well-designed LOC. It’s designed for use with OEM car receivers and offers signal conversion for both the rear and front channels. DS18 V5HL comes as a 2-channel LOC. It’s compact for a more concealed installation.
- Clipping indicators- The DS18 V5HL LOC is uniquely designed in that it comes with inbuilt LED clipping indicators. The LED indicators make it easier to adjust the gain as needed. That way, you can enhance the gain of the signal to enjoy more powerful sound from the factory radio.
- High-level input- This LOC boasts of having a high-level input that’s capable of taking a signal input of up to 50 watts per channel. It outputs a signal of up to 2.5 volts. Its signal to noise ratio is rated at less than 100dB.
- Great frequency distribution- The design behind this LOC allows for perfect distribution of frequency. Thus, you’ll enjoy sound with enhanced clarity across all frequencies. Besides, it will allow your sound system to work at its peak efficiency.
- Easy adjustment- Looking for a LOC that can deliver high fidelity sound? The DS18 V5HL LOC makes it effortless to adjust the gain. As a result, it allows you to maximize the performance of your factory head unit for enhanced sound reproduction.
- Remote turn on- This LOC is unique in that it detects an audio signal automatically. It thereby turns on the amplifier remotely. This functionality also protects the amplifier from malfunctioning.
- High performance.
- Delayed time control.
- Eliminated ground noises.
- Low impedance.
- Compact design.
- Not very powerful.
- Some minor buzzing noise.
The DS18 V5HL line out converter is a perfect choice for pushing the subwoofer, rear speakers, and front speakers without distortion. It’s also perfect for anyone who wants a simple yet functional LOC.
5. NVX XLCA2
The NVX XLCA2 line out converter is designed to accept a speaker level input of 400 watts RMS at most. It comes with advanced features that make it one of the best LOCs out there. Although it comes with a high price tag, its features and performance are worth the extra money.
- xBOOST technology- This LOC features a unique xBOOST technology. xBOOST allows for bass compensation. This technology also allows for bass enhancement. That way, you’ll enjoy deeper and louder bass from your factory radio.
- Selectable auto on- The converter comes with a selectable auto on functionality. You can set it to auto on to only function when your car is in use. That way, it optimizes power efficiency and ease of use.
- High voltage output- Compared to other converters in the market, the NVX XLCA2 offers a more powerful preamplifier output. It’s capable of outputting a preamp voltage of up to 9.5 volts. Its high output means that it outputs cleaner signals for amplification. Consequently, you’ll enjoy less distorted sound.
- Reduced bass roll-off- The technology behind this converter allows for reduced bass roll-off. It ensures that bass is not reduced when turning the volume of the head unit up. Consequently, you’ll enjoy enhanced bass quality.
- Remote control- Another top feature of this converter is its remote control. The remote control features a bass level control knob. It makes it possible to adjust the bass level depending on your needs. The remote control also makes it easier to adjust the bass while on the move.
- Trigger out functionality.
- Dual amplifier outputs.
- Great sound quality.
- 12 volt trigger out.
- Level matching controls.
- Higher price range.
- A little delay when turning the gain up or down.
- A bit challenging to wire to a subwoofer.
The NVX XLCA2 is a great choice for anyone who wants to power high performance and more powerful sound systems from an EOM head unit. It’s also perfect for anyone who loves listening to music with deeper, louder, and cleaner bass.
6. SCOSCHE LOC2SL
The SCOSCHE LOC2SL is designed as a 2-channel line out converter. It outputs an RCA signal for use with subwoofers or amplifiers. Furthermore, it features a compact design for a concealed installation.
- Mountable remote control- One of the top features that stand out most in this LOC is that it comes with a mountable remote control. You can mount the control near the driver’s side on the dash to make it easier to adjust the subwoofer level while driving. You only need to rotate the adjustment knob as needed.
- Incoming signal sensor- The technology integrated into the design of this LOC allows for automatic sensing of an incoming signal. That way, it turns on the amplifier output without the need to remove the car stereo. Also, a turn-on wire isn’t required.
- Compatible with high-powered stereos- SCOSCHE has designed this LOC for compatibility with most high-powered car stereos. It supports an input of 80 watts at most for each channel. Thus, you can add most high-powered aftermarket subwoofers or amplifiers.
- Extra channel- The design behind this LOC makes it possible to add a 2-channel amp or a mono amp. If your factory stereo doesn’t have RCA outputs, this adapter will make it easier to hook a mono or 2-channel amp without having to invest in a new car stereo.
- Low-profile design- Its low-profile design makes it easy to install in tight locations. You can easily conceal it in a way that your passengers won’t notice it.
- Easy to install.
- Adjustable bass level.
- Works with almost all stock radios.
- Can be used with or without the control knob.
- Affordable price range
- The wires are relatively short.
- The bass control knob doesn’t adjust the bass level significantly.
The design behind this SCOSCHE LOC2SL line out converter makes it ideal for quick installation when adding an aftermarket subwoofer or external subwoofer to a stock car stereo.
How to Choose the Best Line out Converter
Hooking an amplifier or subwoofer to a factory head unit or radio can be quite challenging. Luckily, a line out converter can assist you to connect an amplifier or subwoofer to the factory head unit. However, you need to choose a proper LOC to convert the output from a factory radio into a preamp output efficiently. If you choose the wrong converter, you may not enjoy high-quality sound. Thus, it’s important to make your choice wisely. Here’re how to choose the perfect line out converter for your car music system.
Tip #1- Active vs. Passive Line out Converter
When shopping for LOCs, you’ll come across two styles of LOCs. They include active and passive LOCs. To start with, active LOCs are essentially more advanced than passive LOCs. Active LOCs require a power supply of 12 volts to convert and output a signal. They’re capable of handling a power input of 400 watts RMS at most. Thus, you can easily use them with factory amplified head units and powerful sound systems. Also, the best active LOCs come with extra features such as remote turn on and bass restoration.
On the other hand, passive LOCs are low powered. They don’t require any power supply to convert and output a signal. They work by scaling down the speaker level voltage to preamp low-level voltage. Thus, if they receive a weak sound signal, the output will be weak. They’re advantageous due to their simplicity, remote turn-on feature, and power efficiency. However, they’re not powerful enough to work with amplified head units.
Tip #2- Power Input and Output
It’s important to consider the amount of power input a LOC can safely handle and its power output. If your factory radio is amplified or highly powerful, consider a LOC that can handle more power to avoid burning it out. If the factory radio is not amplified, then a less powerful LOC would suffice.
Also, if you want to power a more powerful sound system, you should consider a LOC that can output more power. If the sound system you’re powering isn’t very powerful, then a LOC with a low power output would work efficiently.
Tip #3- Remote Level Control
Another important consideration to make is whether the LOC comes with a remote-level control. While it’s not a must to have one, a remove level control will assist you to control the gain or bass level from the dashboard with ease. That way, you won’t have to keep on stretching your hands to access the converter from its mounting location, something that can be quite unsafe while driving. However, in most cases, a converter with a remote level control may come at a higher price.
Tip #4- Number of output channels
Line out converters are available in 2, 4, and 6 output channels. The output channels determine the number of amplifier channels you can hook the converter to. If you need to connect it to an amplifier alone or a subwoofer alone, then a 2 channel LOC would suffice. If you want to connect it to an amplifier and several subwoofers independently, then you’d need a LOC with more output channels.
Tip #5- Ease of Installation
It’s also necessary to choose a LOC that’s easy to install. It should be easy to wire it to the factory head unit. It should at least come with wires for connecting it to the head unit. Also, it’d help if the LOC comes with an installation manual.
Frequently Asked Questions
Do I need a line output converter to install a new stereo?
Most new stereos come with preamp-level outputs to connect them directly to an amplifier. Such a stereo won’t require a line output converter. Also, if your amp has speaker level inputs, you won’t need a LOC to connect your new stereo as you can connect it directly through speaker level inputs on the amp.
What does a line out converter do?
A line output converter is a device that converts speaker-level signals into preamplifier-level signals. That way, you can convert a radio that doesn’t have preamp outputs to an amplifier via a line output converter. You can also use it to connect a new stereo to a factory amplifier that lacks speaker-level inputs.
Can my line output converter damage my car’s battery?
Line output converters are available as either passive or active LOCs. Passive line out converters don’t require any external source of power. On the other hand, active line out converters require a connection to the car battery. However, it only takes power when receiving a signal to convert. In case it’s not receiving any signal, it won’t drain your car battery. Thus, it can’t damage your car battery.
Do I need an external power source for my converter?
Passive line out converters don’t require an external power source. However, active line out converters require an external power source.
Do all amplifiers require a line output converter?
No. Some amplifiers come with speaker-level inputs. Thus, they don’t require a separate line output converter. Also, most powered subwoofers come with speaker-level inputs and won’t require a line output converter.
Can a LOC damage my stereo?
A LOC won’t damage your stereo as long as you connect it properly. However, a wrong connection may damage your stereo or amplifier.
If your factory head unit lacks a preamp output or RCA outputs, you can still connect it to an amplifier by adding a line out converter. However, choosing the best LOC for your needs can be quite hectic due to the numerous options available. Our reviews have only listed the best line out converters available today. We’ve included the best LOCs within all budgets. Thus, you won’t feel left out regardless of your budget. Hopefully, you’ll find a perfect LOC for your needs from our reviews.
Michael Evanchuk is a San Francisco-based sound engineer with 20 years’ experience installing, troubleshooting, and repairing commercial, automotive, and household sound equipment. Evanchuk owns an auto stereo center, where he offers highly competitive car audio installation and repair services. He has written dozens of articles on different sound engineering topics, all of which have been published in leading journals, blogs, and websites.