Acoustic Boxes: Everything you need to know

Acoustic Boxes: Everything you need to know

on February 23, 2024

At first glance, acoustic boxes look like just a container, simply a rectangle-shaped structure.

However, this appearance is deceptive and is more important than it seems. In fact, these boxes play a fundamental role for audio quality. Its design and construction greatly influence the sound character of a car.

Here we will talk to you about car speakers, what they are, how they work and what their importance is. In addition, we tell you what types of boxes there are. 

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What are acoustic boxes? 

Acoustic boxes are structures, generally rectangular, where the speaker drivers, horns, basses and other hardware elements associated with the circuits are incorporated. They have different models, sizes and various system components.

Their designs vary from simple boxes to more complex computer-made units. You can build them manually or purchase them in specialized sound stores, made of different materials and with even more sophisticated elements. 


How do car speakers work? 

What are acoustic boxes?

A speaker without a box is like a string without a violin. The body of the violin is needed to transfer the acoustic energy created by the vibrating string to the surrounding air.

The speaker box performs a similar function for the vibrating parts of a speaker. Without the box, even the best speaker would sound thin and reedy. 

The physical events at the front and back of a vibrating speaker cone are antagonistic to each other, since vacuum at the back would override compression at the front. The result would be sound cancellation, especially at low frequencies.

The main job of the speaker is to prevent this type of sound cancellation. You should not allow the sound radiation from the front of the cone to collide in the air with the sound radiation from the rear. And, the easiest way to do this is to trap the speaker's rear radiation in the box. The enclosure is airtight and covered with sound-absorbing material. Only the front radiation of the speaker can escape. 

Types of acoustic boxes 

Types of acoustic boxes

Acoustic boxes are essential for better sound. Any speaker will produce sound in a box, but optimizing the relationship between both elements is the key to obtaining optimal results. Shaping the low end (bass frequencies below 200 Hz) is the reason for choosing a particular box type. The three main types are sealed, ported, and bandpass enclosures. We explain them to you, down below. 

Sealed (or closed) boxes 

This is how a sealed box works. The back of the speaker is completely closed. The air inside the enclosure acts as a spring, which helps control the movement of the cone.

When the speaker moves outward, the pressure inside decreases, when it moves inward, the pressure inside increases.This helps create better control over the diaphragm leading to a more precise sound.

A sealed cabinet produces a deep base and more precise sound. They are much easier to design and build than other types of boxes and are typically smaller in size.

Ported Boxes 

On the front of this box, there is a hole (port) that equalizes the pressure between the inside and outside of the speaker.

When the diaphragm returns to the speaker, internal pressure increases, which is channeled through the front port of the speaker. This action increases the sound waves traveling from the speaker, which increases its efficiency.

A ported box produces a more punchy sound. It is large in size and complex to design compared to sealed boxes. 

Bandpass boxes 

Bandpass enclosures are a special type with a port designed for maximum punch.

The woofer is mounted inside a dual-chamber enclosure (one chamber sealed, the other ported), with sound waves exiting the ported side. That sound is very loud within a narrow frequency range. Because bandpass boxes are super efficient within that range, they tend to be a better choice. These enclosures tend to be used for subwoofers. 

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Everyone wants their speakers to perform optimally and produce the best possible sound quality. Fortunately, it is now possible to have the possibility of improving sound through acoustic boxes. These structures prevent the sound generated from being distorted.

There are three main types: sealed, ported and bandpass boxes, each with very specific characteristics.

At Genius Audio we have a diverse catalog so you can equip your car with everything related to sound. We have different models of speaker boxes for cars.

Contact us and choose the best alternative for you.

If you like this article, you might be interested in:

How to Get the Most Out of Your Bass Speaker

Top 5 best car audio amplifiers

Double coil subwoofer: What it is and how to install it


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