4 channel amplifiers provide power and provide up to four speakers with a high-quality audio signal

A 4 channel amplifier is an amplifier that distributes the incoming audio signal to four channels and then amplifies it. So you can use up to four speakers at the same time.

With a 4 channel power amplifier, you can also operate a setup that has only two or three speakers. For this purpose, you switch two channels together and can thus use the power of both channels.

We spend about 4 years of our life in the car, according to a study by Citroen and the market research institute CSA. To make this as pleasant as possible, automakers offer a lot of accessories in the car. What is often neglected, however, is the quality of the car’s sound system.

Fortunately, a variety of well-known manufacturers, such as JBL, Yamaha and Pioneer, provide a solution so you can elicit your audio system with a 4 channel amplifier sound. Also, the additional channels allow you to install a subwoofer.

In our 4 channel amplifier comparison and buying guide we will explain why high and low pass filters are needed to use a subwoofer.

Best Overall

Sony XM-N1004 in-Car Amplifier

Max. Output power (watts): 1000
Rated output power stereo (4 ohms / watt): 2 x 500
Rated output power stereo (2 ohms / watt):  4 x 250
High pass filter (Hz): 80
Low pass filter (Hz): 80
Frequency response (Hz): 5

Sony XM-N1004 in-Car Amplifier Complete Review

With your favourite music, driving is just more fun. A powerful amplifier (1000 watts) delivers cleaner sound to the speakers for enhanced listening pleasure.

Automatic Thermal Control

High temperatures can be detrimental to amplifier components. The amplifier then turns off until the temperature drops again. Automatic Thermal Control reduces the output of the amplifier, so you do not have to worry about the amplifier suddenly failing.

Stay Cool

The amplifier is designed to maximize air circulation within the unit, keeping it cool while providing a stable, powerful sound with no distortion.

Low pass filter (LPF)

music sounds better when the right frequencies are routed to the appropriate parts of the speakers. The built-in low-pass filter ensures that only deep bass is routed to the subwoofer.

High-quality components

Play your favourite songs in superior sound quality. The high-performance stereo amplifier ensures a realistic, reliable sound reproduction thanks to high-quality audio capacitors, output transistors and chokes coils.

High pass filter (HPF)

Like the low pass filter, HPF ensures that everything but the lowest bass is routed to your broadband speakers.

Technical specifications:

  • Channel configuration: 4-channel; 3-channel; 2-channel
  • Max. Channel configuration at 4 ohms: 4 x 170 W
  • Max. Channel configuration at 4 ohms BTL: 2 x 500 W
  • Max. Channel configuration at 2 ohms: 4 x 250 W
  • Frequency response: 5-50 kHz

Second Choice

Pioneer GM-A6704 Bridgeable 4 Channel Amplifier

Amplify your sound experience.

Give in to your longing – the yearning for more achievement. Pioneer bridgeable amplifiers give you exactly what you want.

Technical specifications:

– Max. Output power 1000 watts (bridged) or 4 x 170 watts (4 Ω) or 4 x 250 watts (2 Ω)

– CEA 2006 Power (THD + N = 1%) 4 x 60 Watt (4 Ω)

– output power nom. (RMS) 4 x 60 watts (4 Ω) or 4 x 95 watts (2 Ω) or 2 x 190 watts (4 Ω bridged)

– Stable operation at low impedances 2-8 ohms (stereo)

– Frequency response 10 Hz ~ 70k Hz (+0 dB, -3 dB) Hz

– distortion factor <0.05%

– Signal-to-noise ratio> 95 dB

– Bass boost 50 Hz; 0-12 dB

– TPF 40-500 Hz (-12 dB / oct)

– HPF 40-500 Hz (-12 dB / oct)

– RCA connectors (input)

– Hi-Volt input 300 mV – 6.5 V

– Speaker Input Level 3 – 26V

– power consumption max. (A / 4Ω) 31A

– Housing dimensions 36 x 22 x 6 cm

– Weight 2.5 kg

Buyers Guide for 4 Channel Amplifiers

4 channel amplifier delivers power for up to four speakers

You can operate one loudspeaker per channel.

A 4 channel power amplifier is an amplifier for audio signals. You connect your 4 channel power amp between the sound source, such as the car radio, and the speakers. The signal from the sound source is usually stereo, i.e. two channels are output (left and right). These are split and amplified by the 4 channel power amp, giving you four channels.

With the installation of a 4 channel amplifier, you benefit a better performance of your speakers. The four-channel amplifier sounds better than the one that’s in your car at the factory. Since 4 channel amplifiers are very powerful and deliver up to 1,200 watts, you can now install loudspeakers whose operation requires a lot of power. Also, the two additional channels allow you to connect two additional speakers or a subwoofer.

Configurable channels give you extra power and flexibility

Very large speakers need a lot of power.

The multi-channel amplifiers of many brands, such as Sony, Kenwood and Denon, offer configurable channels. Thanks to this function, the channels can be bridged, i.e. interconnected. Such a multi-channel power amplifier can be used in the following configurations:

  • 4 channel amplifier
  • The 3-channel power amplifier (two channels bridged)
  • The 2-channel power amplifier (four channels bridged)

A four-channel power amplifier can also be used as a 3-channel power amplifier and 2-channel power amplifier.

The channel created by bridging two channels not only theoretically has the power of the two interconnected channels. 4 channel power amplifier tests prove that the bridged channel has twice as much watt as a single channel. If your 4 channel power amplifier has comparable winner qualities, it should be configurable.

Configurable channels are especially useful if you want to extend the sound system of your car with a subwoofer. Subwoofers need a lot of power. Besides, a subwoofer must receive the signal of both stereo channels to fully reproduce the bass. If you connect two channels of your amplifier and connect this channel to your subwoofer, it will be supplied with sufficient power and will receive both the information of the left and the right stereo channel.

If you want to connect a subwoofer to your car’s hi-fi sound system, you’ll need a 4 channel power amp that can be configured to use three channels. If you want to run two high-performance loudspeakers, ohack.in recommends a 4 channel power amplifier that can be configured for 2 channels.

4-channel power amplifier with 1,000 watts provides full power

Digital power amplifiers can be controlled via the app.

The performance is probably the most important feature of an amplifier and so the manufacturers try to outdo each other with the highest possible values. However, the given value is the maximum power that the amplifier can output. The 1,000 watts that a multi-channel amplifier has are therefore not permanently recalled. What the maximum performance looks like in normal operation is indicated by the RMS value, also in watts. However, this is much lower and is rarely communicated by the manufacturers.

Manufacturers also indicate how much power each channel has. Again, the maximum value is specified, not the RMS value. The power per channel depends on the resistance of the connected speaker. This is given in ohms. Since loudspeakers for the car usually have a resistance of 2 or 4 ohms, the 4 channel amplifiers are also designed for this purpose. 

The higher the resistance, the lower the performance of the audio amplifier. If you want to use boxes with a 4-ohm resistor, you should resort to a power amplifier.

The more power an amplifier has, the higher the power consumption. The ohack.in battery test has also taken car batteries under the comparison and concluded that only a few of the tested batteries are good.

If you do not want to install new speakers, but just want to extend the existing car audio system with a subwoofer, you can buy a cheap 4 channel power amplifier. Even power amplifiers with 600 watts provide sufficient power. If you build a completely new and powerful car audio system including a subwoofer, the Ohack.in editors recommend a 4 channel amplifier with at least 1,000 watts. These are great as a subwoofer amplifier.

The high and low pass enables the connection of a subwoofer

A subwoofer is in an audio system is responsible for the bass, so the low frequencies can play efficiently. These range from 10 to 200 hertz. Mid and high frequencies in the frequency spectrum above the bass cannot be reproduced properly by a subwoofer. Therefore, it is important to filter them out of the signal coming from the subwoofer. This task is performed by a low-pass filter.

A low pass filter lets only the low frequencies pass, so the subwoofer only reproduces the bass. Higher frequencies are played by the other speakers. Since the bass frequencies are now reproduced by the subwoofer, they can now be filtered out of the signal that goes to the other speakers. This is done with a high pass filter.

If you want to use a subwoofer, you need a 4 channel amplifier with high and low pass filters. 4 channel power amplifier tests on the internet show that these filters provide dry bass and clear highs.

The following table gives you information about the designation of the frequency ranges:

Designation of the controller

frequency range


0 – 200 hertz

deep mids

200 – 1,500 hertz

high mids

1,500 – 4,000 hertz


4,000 – 12,000 hertz

With an integrated DSP chip you influence the sound of your power amplifiers D power amplifier

The term Class D stands for how the audio signal is amplified. It is often assumed that Class D amplifiers are digital power amplifiers, but this is not the case. Hi-fi power amplifiers of this type are usually labelled with DSP.

DSP stands for digital signal processing. A DSP chip converts the analogue signal into a digital one, processes it in real-time and converts it back into an analogue signal, which is then amplified. The name digital power amplifier usually stands for power amplifiers with DSP chip.

4 channel amplifiers with DSP chip offer the opportunity to change the sound specifically. In most cases, the chip acts as an equalizer. Since the chip works digitally, you can connect your power amplifier to a computer or use your Smartphone to determine how the signal is to be changed.

If you want maximum control over the sound, we recommend using a 4-channel power amp that has a built-in DSP chip. So you can change the sound of your car sound system, without having to buy additional accessories.

These advantages and disadvantages have a 4-channel amplifier with DSP chip compared to one without:

  • Sound can be adjusted exactly to your wishes
  • Control via computer or app is possible
  • Higher purchase price

4 channel power amplifier one-sided connections save space and make installation easier

Cabling a 4 channel amplifier takes up extra space.

Space is in short supply in the car and therefore valuable. Most manufacturers are therefore trying to build their 4-channel amplifiers as compact as possible so that they do not disturb the occupants. 

However, not only is the size of the multi-channel power amplifier critical, but it also needs to be wired and takes up extra space. Some of the best 4 channel power amps have been designed so that all ports are on one side.

In your car, there is an acute lack of space and you still do not want to give up the benefits of a 4-channel amplifier? Then Ohack.in recommends a model that has all the ports on one side.

FAQ about 4 channel amplifier

When do you need a 4 channel amplifier and when do you need a 2 channel amplifier?

As the name implies, a 4 channel power amplifier has twice as many channels as a 2-channel power amp. For every speaker that you add to your sound system, you need a channel on your power amplifier. If you have a normal stereo setup, you need a two-channel amplifier. If you want to use four speakers, you need four channels.

Exceptions are subwoofers. On the one hand, they need more power than an ordinary loudspeaker; on the other hand, you have to get the audio signals of both stereo channels to play the bass correctly. To connect a subwoofer, you, therefore, need two channels that you need to bridge.

What must be considered when connecting a subwoofer?

If you connect a subwoofer to your sound system, you must first bridge the right channels. You need both of the two left and one of the two right stereo channels. This is not a problem, especially with configurable 4-channel amplifiers.

You must also make sure that you activate the low-pass filter on the two channels that you have bridged. Often this carries the name low-pass. On the remaining two channels you now activate the high-pass filter, which is usually called High-Pass.