The choice of materials for the manufacture of the speaker cabinet


Created on 27.02.2020 10:18.

Updated 02.28.2020 09:05.

Author: Dmitry Pirozhkov.

A modern acoustic system (AC) is an integral attribute of a number of audio equipment. The purpose of acoustic systems is to convert an electrical impulse into an audio signal. And throughout the development of speakers, the desire of the creators has been aimed at reducing distortion and obtaining the highest possible sound quality.

This is what gave rise to two main types of speakers, which differ in connection with an amplifier. If the amplifier is directly built into the system, then such a speaker system is called active, if the amplifier is external, then it is passive. In addition, a distinction is made between ceiling and floor systems with different dimensions. The price range of the speaker consists of budget variations, Hi-Fi and Hi-End classes.

But if at the dawn of their development, acoustic systems, conventional horn loudspeakers did not have a housing at all, then with the advent of paper diffusers, the approach to creating high-quality speakers has changed.

Why choose materials for your speaker cabinet?

All the stuffing of the acoustic system was placed in special frame structures. Considering that until the mid-twentieth century, electronic circuits were based on lamps, they needed to be cooled. All this dictated the design of the first speaker enclosures.

But even then, many loudspeaker designers noticed that the body material has a certain effect on the formation of sound in structures. So, different walls of the speaker cabinet (front / rear) emitted sound of different phases, which significantly affected the sound quality. That is why the relevance of both the design itself and the material for the manufacture of the speaker housing has greatly increased.

More and more attention has been paid to the acoustic properties of a wide variety of materials that could be used in the manufacture of enclosures.

Minimizing speaker distortion

Regardless of what type of acoustic design, as well as what material was used, the main task of the research was to minimize the distortion of the emitted sound signal. Timbre, tones of voice, various sound effects – everything is important, therefore the most stringent requirements were imposed on the speaker cabinets.

An ideal acoustic system should not only guarantee minimization of sound errors, but also allow high-quality reproduction of the entire sound range available to the human ear, often (20–20,000 Hz). And this applies to both mono-channel and stereo sound. The enclosures of modern acoustic systems must satisfy the consumer not only with sound, but also with an aesthetic look.

Most modern loudspeaker manufacturers identify wood as the most acceptable material for loudspeaker enclosures, wood. In a broad sense, materials derived from wood are also meant: plywood, MDF and chipboard. Less commonly, but also used stone, ordinary and organic glass, glued wood, metal. Let’s consider in more detail the sound materials of acoustics and exclusive solutions.

Plastic is cheap but resonates

Plastic, which also includes composites, is often used in the production of budget speakers, those that are still Chinese. The plastic body is lightweight, significantly expands the possibilities of designers, thanks to casting, almost any shape can be realized.

The different types of plastics differ greatly in their acoustic properties.

Plastic speakers can be very good, but the main thing is to choose the appropriate plastic for the case.

Plastic is very popular when creating wearable speakers that work via Bluetooth, such as the JBL. At the same time, the manufacturers managed to solve the problem of resonance.

Wireless speaker Philips SB500A

A few years ago, plastic was not very popular in the production of high-quality home acoustics.

But at the moment it is in demand for professional samples, where low weight and mobility of the device are important.

Chipboard: Particleboard

This material is based on glued shavings. As a result of pressing, a flat surface with a non-dense core is obtained. Chipboard, passing sound, dampens vibrations, but is afraid of moisture, as it tends to swell and collapse. The choice of chipboard to create speaker enclosures is explained by the fact that the product does not create resonance and does not distort loud sound.

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Sound absorption is inhomogeneous and low and mid-frequency resonances may appear, although the likelihood of their occurrence is lower than that of plastic.

It is necessary to pay attention, both in the case of plastic and in the case of chipboard, to the properties of a particular board.

It is important to take into account the density and moisture content of the material, since different chipboard boards differ in parameters.

Thick (> 22 mm.) And dense chipboard is used to create studio monitors.

The chipboard construction will not add any additional overtones to the sound. And delamination under the influence of moisture is minimized by putty, special paint and various materials used as cladding.

The most significant problem of chipboard is low strength, with a sufficiently high mass of material.

Chipboard with a density of more than 650–820 kg / m³ (with a slab thickness of 16–18 mm, and more) and a moisture content of up to 6–7% are suitable for creating an AU.

Failure to comply with these conditions will affect the sound quality and reliability of the speaker system.

Lined or laminated chipboard

Another variant of chipboard is chipboard, with one-sided / double-sided veneer or plastic (laminate) with a decorative pattern. Everything is fixed with special glue.

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The disadvantage is the need for additional processing of edges and corners. If the saw is poorly sharpened, the laminate may chip.

Joiner’s plate

A blockboard is made from double-sided veneer or plywood. A filler made of bars, laths and other material is placed inside between the two surfaces. Outside, such material is faced with veneer or plywood.

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The resulting material is easy to process and lightweight.

OSB: oriented strand board

In other words, multi-layer glued plywood, consisting of recycled wood waste.

The texture of the OSB is very beautiful, but uneven; the unevenness is sanded and varnished.

The resulting material absorbs sound well and is sufficiently resistant to vibrations.

These properties are required for acoustic screens when creating a Shredder panel. An acoustic screen located at a given point emits in antiphase and dampens an acoustic wave of a certain length.

Minuses: Evaporation of formaldehyde and strong odor.

MDF: fine fraction (fiberboard)

Smooth surface material in various thicknesses (from 10 to 22 mm), allowing for a wide variety of speaker cabinet configurations.

The reasonable cost of MDF, affordable processing and gluing of the material make it one of the most popular in creating the most fancy speakers, due to its high level of mechanical strength. The finished product looks more reliable …