What is a Bandpass Box and the Pros and Cons?

What is a Bandpass Box and the Pros and Cons

What is a Bandpass Box and the Pros and Cons?

What is a Bandpass Box? (Bandpass subwoofer box pros and cons)

When you want to get the full potential of low-pitched frequencies, you usually make use of a subwoofer, because a regular speaker doesn’t help you in this regard.

A subwoofer is also known as a sub or a woofer in some parts of the world. The only difference between a subwoofer and a normal loudspeaker is that the former helps to highlight the low-pitched frequencies, also known as bass, to the best possible extent.

Once you have decided to choose the subwoofer, the next common question that would come to your mind is whether you need a proper enclosure for it. Yes, the right enclosure helps the subwoofer to highlight the right quality of bass eventually.

When you go to buy enclosures, you will be presented with quite a lot of options such as sealed, ported and bandpass. While most of the people are clear with the features about sealed and ported enclosures, they have some ambiguity regarding the bandpass subwoofer box.

In this article, we will provide you with some basic details such as what the bandpass box is all about when you will need it and the pros and cons of using this box. After reading this article, you will get a clear idea if this type of enclosure is the right fit for your audio-related requirements.

Types of Subwoofer Enclosures – A Brief Overview

If you thought that the subwoofer alone could help to produce the perfect quality of bass, you are mistaken. The subwoofer needs to be enclosed in the right type of box, constructed in the right way, to give a nice throw to the bass that you eventually hear.

The three main types of subwoofer box options that you will find in the market today are the following:

Sealed boxes – This is where your subwoofer is enclosed in an airtight box to give a nice feel and tone to the bass that you want to hear. You can buy this type of subwoofer box when you want to hear deep bass. The best part of this enclosure is that it is very compact, but the downside is that it requires a lot of power for its working.

Ported boxes – If you prefer to hear the bass clearly in heavy & hard music such as rock, hip-hop and heavy metal, you can use a ported subwoofer box. As the name indicates, this box uses a port to highlight the quality of bass. However, they are slightly complex to tune and occupy a large space.

Bandpass boxes – If you are looking for bass sounds that boom well a bandpass box is the right fit for you. It wouldn’t be wrong to say that the bandpass box is a combination of a sealed and a ported design.

Here, the subwoofer is carefully kept inside the enclosure that has two chambers, out of which one is of the ported design and the other belongs to the sealed design.

The sound that comes out eventually is from the ported chamber. The sound is super-loud here, which is why this enclosure is considered the best to highlight the low bass notes for hard rock, rap, and hip-hop.

Bandpass subwoofer box – A look into its design and modus operandi

Today, the bandpass subwoofer box is one of the commonly used designs in many residences. This is because it helps to give out a very loud noise in a narrow frequency.  The bandpass design is not a new concept in the audio industry. It was in 1934 that Andre d’ Alton filed his first patent for the bandpass box design.

Why is it considered very powerful?

Have you ever wondered why a subwoofer enclosure was named, “bandpass”?

This is because the enclosure could allow only a certain range or band of bass to pass through the box and reach the listener. With this basic meaning in mind, it would become easy for you to understand how the bandpass box operates.

In a bandpass box, the sound output is directly transferred into the ported chamber, which is placed at the front. It is in this chamber that the sounds are filtered and the box decides to pass only that band of sounds that aren’t of very high frequencies.

This is why you will be able to enjoy a deep bass sound in a narrow frequency when you use a bandpass subwoofer enclosure. None of the other types of enclosures will give you the output of deep bass that a bandpass box gives you.

Sound lover’s favorite

If you are a person who loves to experiment with different bandwidths and frequencies of music, you will love the bandpass box enclosure because it gives you a lot of flexibility while deciding the final quality of audio output.

It helps you customize the sound features based on your preferences and mood. Some of the options that you can try with the bandpass box are the following:

  • Volume control adjustments in the chambers found at the front & back
  • Tuning of the port to adjust the frequency as per your preference
  • Adjusting the efficiency of the subwoofer box for narrow & broad frequency bandwidths
  • Extremely low-frequency extension when the box is operating at a wide bandwidth
  • An excellent transient response can be achieved by arriving at a middle-level bandwidth range after trying out various high and low ranges
  • Subwoofer box parameters can be adjusted easily in each bandwidth range to increase or decrease the range of sub-bass that is produced eventually

Bandpass Subwoofer Box Pros and Cons

Now, let us see some of the advantages of a bandpass subwoofer box. Every coin has two sides to it. All you need to do is analyze the pros and cons carefully and compare them. If the pros outweigh the cons, this design is apt for you. If you feel that the cons are too big to ignore, then you may have to look for another subwoofer box design.


  • Helps to achieve a deep bass extension that is not possible with most other subwoofer box designs
  • Gives extreme flexibility to the user by offering various customizations to adjust the bandwidths and the final range of sub-bass that is produced
  • Helps you have great control over the sound quality produced when compared to the traditional speakers & subwoofer designs; this is because the cone moves as per the bandwidth of the frequency that you want in this model
  • The durability of the woofer is guaranteed because it doesn’t move much even though it produces the highest quality of sound output; also, chances of the woofer getting damaged due to wear & tear are almost nil


  • Not very easy to build and design your own bandpass subwoofer box, unlike the other simple designs of sealed & ported models
  • Quite hard to tell when the woofer runs into trouble because the noise comes only from the front chamber and due to the reduced movement of the speaker
  • When the problem with the speaker isn’t identified in the early stage, it can cause the entire bandpass box to blow up within minutes
  • While this design is great for a deep-bass output, it isn’t the right choice if you love a good upper bass output
  • If the bandpass enclosure is quite small, the frequency response is not as uniform as you would have liked it to be; this means, some frequencies may come out louder than other, leading to distortion of the final quality of the sounds

Types of Bandpass Boxes

You have got an idea of a bandpass subwoofer box and what it will do to the sound that you finally hear.

When you set out to buy a bandpass box for yourself, you will note that there are two options that you can pick from – the single reflex bandpass and the double reflex bandpass. What do these types mean and which one is right for you? Keep reading to know more about the same.

In a single reflex bandpass box, the sealed chamber is found at the rear, while the ported chamber, through which the sound comes from, is found at the front. In a double reflex bandpass box, the chambers of the front and rear areas are connected to the listening area itself, with the help of a port.

The transient rate is quite good in a single reflex bandpass box, where the frequency range is around 12/dB/octave. However, in a double reflex bandpass box, you will be able to experience a sharp sound quality as the frequency range is between 18 and 24/dB/octave.

If you are looking for a bandpass box that emits the best possible quality of music in a small enclosure with the right frequencies and great transient features, the single reflex design is the perfect choice for you.

A dual reflex bandpass box may not be a practical choice for you, because it occupies a very large space and also doesn’t have a good transient response.

Last update on 2024-02-25 / Affiliate links / Images from Amazon Product Advertising API

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