What Is A Monoblock Amplifier? (Monoblock Vs. Stereo Amps)

Norvan Martin
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Monoblock amplifiers and stereo amplifiers are popular choices among car audio enthusiasts who wish to get the most from their sound systems.

Many people are familiar with stereo amplifiers, but what are monoblock amplifiers and what are they used for?

What is a Monoblock Ampliwfier?

A monoblock amplifier is a one-channel amp (mono means 1) that provides superior power amplification and can be used to power single or multiple subwoofers. Monoblock amplifiers are popular for car stereo systems. 

Monoblock Amplifier

Given that this type of amp has a channel speaker, the sound system dedicates all power to the single-channel, you can pair them with multiple-channel stereo amplifiers for a refined and balanced tone and an overall higher quality sound. 

Why Do You Need A Monoblock Amp With Your Subwoofer?

You probably know about stereo amplifiers and know about connecting a stereo amp to speakers and subwoofer. For example, you can connect passive subwoofers to two-channel (stereo) amplifiers

However, subwoofers produce low-level frequencies or bass sounds. These low frequencies are normally below the 80 Hz range. On the other hand, a stereo amplifier works with both the left and right channel signals, producing a full stereo output. 

Monoblock Amp With a Subwoofer

Regular car speakers such as stock speakers and door speakers cannot produce these low frequencies effectively. 

Your factory car stereo is not designed to power high-RMS subwoofers either. They are simply designed to drive low-power loads like dash tweeters and door speakers.

If you want powerful bass, you need a subwoofer and that subwoofer will need a power greater than what your car stereo can provide. This is why you need an amplifier.

The best amplifiers to power a subwoofer are monoblock amplifiers, especially if you are a bass lover who trying to create smashing bass effects.

This is because monoblock amplifiers are dedicated to delivering low-frequency bass power. They are not full-range amplifiers, meaning they do not pass low, mid, and high frequencies, only low frequencies. In other words, Monoblocks are ideally suited to drive the low-frequency audio signals that your subwoofers use.

How Do Monoblock Amps Work?

Given that a mono amp only transmits a single-channel audio signal, you should not use it for stereo music.

They work similarly to regular amps, except that they have discrete controls like low-pass and subsonic filters to limit frequencies to low tones. 

How Monoblock Amps Work

As we have said, the amplifier can give the best output when connected to a low-frequency subwoofer, which means you can reap the most by using it with a subwoofer. 

Why do many people use monoblock amplifiers in cars?  The principle we have discussed above still applies.

Dash tweeters and stock factory door speakers cannot reproduce frequencies below the 80Hz range.  For that matter, if you attempt to play re-bassed music on a 6.5-inch, coaxial, and component speaker, you will get an unpleasant muddy, and distorted sound.

Remember that factory car stereos cannot power high-end subwoofers. But they efficiently power the stock audio system. In other words, if you desire to get quality bass that leaves a lasting impression in your car, you need to use a sub, and you should power it with a monoblock amp as well. 

Why Does Bass Play On A Single Channel? 

Keep in mind that bass frequencies are omnidirectional which means that they spread out in all directions and they spread quickly!

Because of this, you do not need to balance the sound with a left, center, and right channel. 

Types of Monoblock Amplifiers

There are two types of monoblock amps. These are class AB and class D “Digital” monoblocks, and each of them works uniquely. 

Class AB Monoblocks

Class AB monoblock amplifier designs are found in many high-quality amps with line-level inputs that serve as triggers. 

Class AB Monoblocks

The amps keep trying to sense signals, and whenever it detects any signal, the amplifier permits the power to pass through.

Class AB monoblocks always allow some power to keep flowing to the switch. When a signal is detected, the power supply increases. 

As the name suggests, this type of amp consists of Class A and Class B amplifiers. The former is power-hungry but produces a cleaner sound. The latter is class is incredibly energy-efficient but less accurate.

Despite the differences in these features, a monoblock amp still has a single input, a single amp circuit, and a single power supplier, which guarantees higher quality and refined sound.

Class D Monoblock Amps

Even though class D monoblocks have single channels like their other counterparts, the amplifier operates entirely in a different way from Class AB amps.

Class D Monoblock Amps

Unlike AB amplifiers, which have an always-on power supply, the Class D monoblocks simulate the input signal’s waveform.

In other words, these amplifiers often switch power on and off after a short period, which makes them more efficient. You need to be careful with this however because it can lead to subwoofer popping issues

Due to the increased efficiency, class D monoblocks use less energy than the traditional AB amp designs. The digital version is also much smaller but gives quality sound.

Benefits of Monoblock Amps

Below, we discuss the main benefits of using monoblock amplifiers:

1. Reduced Load On Your Stock System

Remember, monoblock amplifiers are specially designed to produce low frequencies and so they do this quite efficiently. 

Once your monoblock amplifier is properly tuned, it will power your subwoofer efficiently and lighten the load on your factory amplifier substantially. To learn more, check out our article on how to turn a monoblock amplifier

This is because the factory component speakers will not reproduce frequencies that they were not designed to play. Doing this will result in improved sound quality and a greater life for your factory system. 

2. Stable to High Electrical Current

Monoblock amplifiers are stable to 2 ohms, which shows that they can resist a high amount of current.

This quality shows that these amps can deliver enough watts to power two speakers rated as high as 4 ohms each without requiring an additional sub.

At the same time, if you wire the speakers in parallel, you can safely connect two 4-ohm subwoofers without putting speakers at risk. Please check out our guide on how to wire a monoblock amplifier to learn more. 

3. Affordable

Monoblock amplifiers are much simpler than multi-channel amplifiers.  Due to this, they are much cheaper as compared to buying a stereo amp to replace the factory amp. The cost is low, but you can use it as your sub’s dedicated power supply. It’s cleaner and richer-sounding content at an affordable cost.

4. Useable in home audio apps and car

While monoblock amplifiers are popular for cars, people have the option to use these amplifiers in home audio apps and cars.

5. Excellent Performance

The fact that monoblock amps only handle a single channel means that you will not face the risk of multiple channels bleeding together.

Besides, they deliver an adequate amount of the required power. This way, the sound remains clear and doesn’t interfere with other channels.

Disadvantages of Monoblock amplifiers

1. Can Be More Expensive

Each monoblock amp is a separate unit. So, to set up the sound system with the blocks, you have to spend a little more time and money.

Also, if you are replacing your factory amp and going for a stereo amp and a monoblock amp, that setup will be more expensive than the factory amp and the monoblock amp together.

If the cost of setting up the systems is your primary consideration when choosing an amplifier, then you should opt for multi-channel amps.

But multi-channel systems also take up a lot of space and present wire-routing challenges. Check out our guide on how to properly wire a monoblock amp to learn more. This is a common problem that occurs since each amp has its power cord.

How to Power Monoblock Amplifier

A car’s alternator determines the amp’s power. How you power the amp depends on the number of amplifiers that an alternator can drive. If necessary, start the process by upgrading the alternator’s power output.

One way to improve power is to include a more powerful battery. However, the alternator should be able to power all the batteries efficiently.

All of the devices in your audio system require an adequate amount of power to work properly. As such, purchasing these devices that pull so much power may not serve you well.

If your car has efficient shock alternators, you have nothing to worry about. They are often able to power up at least a monoblock amp efficiently. In most cases, these amplifiers deliver as much as 800-100 Watts.

Is A Monoblock Amplifier Better?

In comparison to stereo amplifiers, most people aren’t sure which is better, and actually, it is hard to give a direct answer because, in the end, it all depends on preference which varies between individuals.

In this kind of argument, monoblock amplifiers have been argued to be better in sound quality because the transformer and power supply are dedicated to just one channel other than stereo amplifiers where it is shared between two channels.

Furthermore, most people even prefer to buy monoblocks than a stereo.

Best Monoblock Amplifier

There are different brands of Monoblock Amplifiers and below is a list of some top-rated monoblock amplifiers:

1. Rockford Fosgate R500X1D: This amplifier has a power handling of 500W RMS and has a frequency range of about 20Hz – 250Hz

2. BOSS Audio AR1500M: It has a power handling of 1500W max (not RMS) with a frequency range of 35Hz – 2200Hz

3. Planet Audio AC1500.1M: This has a power handling of 1500W max RMS and a frequency range of 15Hz – 20KHz.

4. Kicker 43CXA6001: It has a power handling of 600W RMS and a frequency range of 25Hz – 200Hz.

5. RIOT R1100M: This has a power handling of 1100W max and a frequency range of 9Hz -50,000Hz.


What’s better mono amp or 2 channel?

A monobock amplifier is better for powering a subwoofer since they are powerful 1-channel or mono amplifiers. On the other hand, 2 channel amplifiers are best for powering door speakers and/or rear speakers. Check out our article on monoblock vs 2 channel amplifiers to learn more. 

Is a Monoblock amp 2 channel?

Monoblock amplifiers are not 2 channel amplifiers, they are one-channel amplifiers as their name suggests ‘mono’ or single channel. In addition, monoblock amplifiers cannot be bridged. The 2 outputs of a monoblock amplifier are there to easily connect multiple subwoofers and not 2 channels.

Is a Monoblock amp better?

Monoblock amplifiers are the best amplifiers for driving subwoofers. They can also drive multiple subwoofers wired in series or even parallel depending on impedance considerations. An example of a good monoblock amplifier is a CLAS D Monoblock 1-ohm stable amp.

What is a Monoblock amp used for?

Monoblock amplifiers are used to drive a subwoofer. They can also be used to drive multiple subwoofers. 

Is a Monoblock amp good for subs?

Monoblock amplifiers are the best amps for subwoofers and will drive the strongest bass response from your subwoofer. A monoblock amp meets the specific requirements of a subwoofer and can handle all the power without overheating.

How many speakers can a monoblock amp run?

Monoblock amplifiers have one channel and so will only give a single-channel output. This means you will not get a left and right channel from a monoblock amplifier. These channels are merged into one. However, some monoblock amplifiers have 4 speaker output terminals. This means you can connect multiple speakers, but they will all play a single channel. 

Can a monoblock amp run speakers?

You can connect a speaker to a monoblock amplifier, but the speaker needs to be a full range speaker which means it can play all range of frequencies. 

What’s the difference between a monoblock amp and a regular amp?

The main difference between a monoblock amplifier and other amplifiers is the number of channels. A monoblock amplifier has 1 channel while a 2 channel amp has 2 channels and so on. In addition, monoblock amplifiers are designed to handle all the power required by a subwoofer.  

How do you adjust a monoblock amp?

To adjust a subwoofer, do the following:

  1. Keep all your head unit settings flat. This means you need to keep all bass boosts, gain, and other effects should be at the minimum level or turned off.
  2. Turn the head unit volume to the loudest it can go without experiencing any distortion.
  3. Turn up the low pass filter to the maximum level.


Monoblock amplifiers are single-channel amplifiers designed to drive subwoofers. You can pair monoblocks with several channel stereo amps for a balanced tone and refined sound.

We trust that this article has helped you to understand monoblock amplifiers and how you can use them as required to create your desired sound quality.

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Norvan Martin is the founder of BoomSpeaker.com. He is a professional Electronics Engineer and is passionate about home theater systems and AV electronics. BoomSpeaker was created as an online hub to share his knowledge and experiences as it relates to home theaters and home audio electronics. My email: [email protected]  Connect on Pinterest and Linkedin