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What Is a Line Driver in Car Audio?

Do you want the best sound experience out of your car audio system? Are you looking to make sure that your music sounds as clear and powerful as it can?

If so, then you have probably heard people throwing around the term “line driver,” but what exactly is a line driver in car audio, and how does it impact your overall sound system performance? Let’s find out.

A line driver is an electronic amplifier circuit that boosts the output voltage from an audio source, such as a car stereo, to improve the audio signal strength and clarity before the signal reaches the amplifier or sound processor. Line drivers can also provide better dynamic range and a quiet, noise-free signal.

As an Amazon Associate, ImproveCarAudio will receive a small commission from qualifying purchases made through the links in this article.

Tip: When you search for the line drivers, you will find active and passive models.

The difference is that active line drivers can make the output signal much stronger, which does not require setting gain so high on the amplifier.

An excellent active yet not expensive line driver is the AudioControl LC1il (link to Amazon). This little two-channel guy is perfect for the sub’s amplifier, where you can focus on narrow frequencies.

In this article, I will look closely at line drivers and how they can benefit your car audio system.

What Is a Line Driver?

At its most basic, a line driver in car audio is an amplifier designed to boost an audio source’s output voltage taken directly from the car stereo.

This can be particularly useful in a car audio system, where the signal strength and clarity of the audio may be affected by long cable runs or multiple devices being connected to the system.

By increasing the voltage of the audio signal, a line driver can help to reduce the amount of noise introduced into the system and improve the overall quality of the sound.

For example, you have a car stereo connected to an amplifier via a long cable run. As you know, the longer the cable, the more susceptible the signal is to interference and noise.

By using a line driver between the car stereo and the amplifier, you can boost the voltage of the audio signal and reduce the amount of noise transferred into the system.

This can result in a more precise and dynamic sound without annoying hissing or static. 

When Do You Need a Line Driver?

A line driver may be helpful in a car audio system in a few different situations. Here are a few examples:

#1. Long Cable Runs:

As mentioned earlier, the longer the cable between your car stereo and your amplifier, the more susceptible the signal is to interference and noise.

A line driver can help boost the voltage of the audio signal and reduce the amount of noise introduced into the system, resulting in a clearer but, more importantly, stronger sound.

#2 Multiple Devices:

You may also benefit from using a line driver if you have multiple amplifiers connected to your car’s audio system.

It can help ensure that all the devices receive a solid and clear signal, which benefits the listening experience.

Line drivers are also handy in increasing SPL in many car audio systems when connected directly before subwoofer amplifiers.

#3. Poor Signal Strength:

If you’re experiencing poor signal strength or clarity with your car audio system, then a line driver could be the answer to reduce noise and improve the overall sound quality.

Benefits of Using a Line Driver:

There are a few key benefits to using a line driver in your car. Here are a few examples:

#1. Better Dynamic Range

Dynamic range is the difference between the loudest and softest parts of a piece of audio.

By boosting the voltage of the audio signal, a line driver can help to improve the dynamic range of your car audio system, resulting in a more lifelike and enjoyable listening experience.

#2. Quiet, Noise-Free Signal

One of the main benefits of using a line driver is the improvement in signal clarity.

By increasing the voltage of the audio signal, a line driver can help to reduce the amount of noise that is introduced into the system, resulting in quieter journeys.

Which Is the Best Line Driver?

Many different line drivers are available on the market, ranging from budget options to high-end models. 

I will show you two. My favorite AudioControl Matrix Plus and less expensive 2-channel AudioControl LC1il.

AudioControl Matrix Plus

The AudioControl Matrix Plus line driver (link to Amazon) is a powerful amplifier that can boost the voltage of your audio signal up to 12V and increase the dynamic range up to 20dB

AudioControl Matrix Plus Black Six Channel Line Driver with Remote Level Control Input

It also features an adjustable bass boost and treble contour control to customize the system to personal preferences.

If you’re an audiophile looking to get the best sound possible from your car audio system, or increase SPL from the subs, consider the AudioControl Matrix Plus. 

With its ability to boost the preamp signal levels up to 9.5 volts RMS/13 volts peak, this line driver can transform the sound of your system and give it the boost it needs to deliver robust, high-quality audio.

In addition to its gain controls, the Matrix Plus also features balanced differential inputs and low-impedance outputs, which can ensure that your audio is transmitted with minimal distortion and interference.

With its high signal voltage capability, 24 dB of gain, and a range of features designed to improve audio quality and clarity, this line driver is sure to help you get the most out of your system.

Some of the key pros of the Matrix Plus include:

#1. 24 dB of gain

#2. Balanced differential inputs

#2. Low-impedance outputs

#4. Optional dash control input for the ACR-1 remote (link to Amazon).

On the downside, this line driver may not be suitable for users looking for a simpler, more budget-friendly option. 

AudioControl LC1il

The AudioControl LC1il 2-channel line driver (link to Amazon) is also a highly effective and reliable option for audiophiles looking to boost the performance of their car audio systems.

AudioControl LC1i Active 2-Channel Line Driver/Output Converter with Impedance Matching

Although it supports only two channels, it is beneficial with less advanced aftermarket and factory audio systems or when you want to use it specifically for the subwoofer.

Some of the key benefits of the LC1il include:

#1. Its ability to provide up to 9.5 volts of preamp-level output

#2. Its compatibility with both preamp and speaker-level inputs

#3. Its speaker-level inputs can handle up to 40 volts (equivalent to 400 watts RMS)

#4. Its level control and Maximized LED indicator allow you to easily adjust the signal strength and ensure that your audio is free from distortion

On the downside, there are a few things to consider when it comes to the LC1il:

#1. It does not come with wiring, fuse, or hardware, so you’ll need to purchase these items separately

#2. It is recommended that you use 18-gauge power and ground leads and a 1-amp fuse for optimal performance

Regarding installation, it is extremely simple, and I have found AudioControl LC1il, thanks to its low profile, can fit under the trunk liner in most cars without any issue.

Still, the biggest thing that makes me happy is the higher signal boost compared to the passive version and the entirely removed engine noise with a whining sound.

Conclusion

Whether you’re looking to drive long cable runs or connect multiple devices to your car audio system, a line driver can provide the boost you need to get a solid and clear audio signal.

With features like gain controls and clip indicators, line drivers can help you fine-tune your system’s sound and avoid distortion.

If you’re interested in improving the sound of your car audio system, consider using it to give your system the boost it needs.

FAQ

What Is a Line Driver, and What Does It Do?

A line driver is an electronic amplifier circuit that boosts the preamp output voltage of a car stereo to improve the signal strength and clarity of the audio being transmitted.

When Do I Need to Use a Line Driver?

A line driver may be especially helpful when you have a long cable run between your audio source and your amplifier or when connecting multiple devices to your audio system.

What Are the Benefits of Using a Line Driver?

Some benefits of using a line driver include better dynamic range, a quiet and noise-free audio signal, and a high headroom power supply that can boost the preamp signal by up to 24 dB.

What features should I look for in a line driver?

Some features to consider when looking for a line driver include gain controls, clip indicators, and a variety of inputs and outputs to accommodate different audio sources and devices.

What Features Should I Look For in a Line Driver?

Installing a line driver in your car audio system typically involves connecting the line driver between your audio source and your amplifier using RCA cables and adjusting the gain and other settings as needed.