News & Trends

We all use speakers and often invest time and money not getting better audio quality from our setups. But without understanding how speakers actually work, how can you judge what makes one model better than the other? And how can you be sure  you’re  getting the most out of your expensive new speaker? 

This guide on speaker mechanics is designed to give you the knowledge to fully appreciate the engineering behind the sound you hear every day. If you’re a beginner,  understanding these fundamentals will help you spot underlying differences in speaker construction and sound quality.

The Science Behind Sound Reproduction

What we call sound is ultimately nothing but vibrations. When an object vibrates, it transmits that disturbance into the air, creating a pressure wave that expands outwards. That’s a soundwave.

When this sound wave reaches our ears, the eardrums vibrate in response, and these vibrations are converted into corresponding electrical signals that our brain interprets as “sound”. This process is also the key to artificially reproducing sound.

To record sound, a device must convert these vibrations to electrical signals as well. To reproduce it, a speaker must interpret the electrical signals to produce the same pattern of vibrations, recreating the sound wave. This is usually achieved by using electromagnetism to convert the signals into physical vibrations of a speaker component, which will be explained in greater detail later.

Every sound wave has specific characteristics that a speaker must replicate. Like all waves, a sound wave is mainly characterized by its frequency and amplitude. All that the electric signal needs to record is the intensity and frequency of these vibrations, and that is enough to let it replicate the sound again.

Core Components of a Speaker

We have explained how a speaker’s job is to convert electrical signals into vibrating sound waves, but how exactly does it achieve this? There are multiple key components involved in this process, and we will  explain how they work.

Main Parts of a Speaker

Cone

The cone is the most visible component of the speaker, and the thing you picture when you think of one. Also called the diaphragm, it performs a similar function to our anatomical diaphragm, displacing air to create pressure waves.

But in this case, it is not to breathe, but to produce sound. The cone is basically a membrane controlled by the voice coil, and its deformations create the pulses of a sound wave.

Voice coil

The cone of a speaker might be the component that vibrates to produce the sound, but it is the voice coil that actually drives it.

It is exactly what the name says: an electrical coil. Suspended between magnets, it vibrates in response to the electric signal being fed to the speaker, causing the cone to vibrate, which creates the sound.

Magnet

A powerful magnet is the bridge that converts electrical signals into sound vibrations.  By producing a powerful magnetic field around an electrified coil (the voice coil), the coil is pushed with magnetic forces, with an intensity and frequency decided by the input signal.

This works because the electrified coil acts as a smaller magnet, causing it to be repelled and attracted in various directions by the larger magnetic field.

Suspension

A humble component, but nevertheless an essential one. The suspension’s job is to keep the voice coil suspended inside the magnet, letting it vibrate without moving completely out of position.

How These Parts Work Together

The complete process works something like this:

First, the electric signals that constitute the sound are passed through the voice coil. The signal fluctuates with the characteristics of the recorded sound, and the coil’s resultant magnetic effect also fluctuates in tandem.

As the coil is suspended in a strong magnetic field, it is pushed and pulled by magnetic forces in response, which causes it to vibrate with the cone it is directly attached to. The cone then flexes in place, creating vibrations in the air itself, effectively reproducing the same sound waves that were transcribed into the electrical signal.


The speaker enclosures in which the speakers are mounted also play an important role in the overall sound quality that is produced.Apart from isolating the sensitive electromagnetic components from outside interference, a speaker’s box also helps in the quality of the bass output. This is because the voice coil not only vibrates the cone, it also vibrates the air behind it. And while its contribution isn’t significant for the high-frequency sounds, it has a major impact on lower-frequency sound waves. This is why the size of the speaker box and the volume of air in it are also carefully designed to give the best bass performance.

We have looked at the most common way speakers work, but that isn’t the only way. Ultimately, all that a speaker needs to do is produce vibrations based on electrical signals, and a cone with a voice coil driving it isn’t the only way of achieving that.

Speakers use alternative technologies to produce these vibrations. For example, some speakers use electrostatic panels. The principle is simple; a thin diaphragm is suspended between two electrocharged panels of opposite polarities. When an electrical signal is passed through the diaphragm, it is subject to forces varying with the signal’s fluctuations, causing it to vibrate.

Another method suspends a thin metal ribbon between magnetic panels. The concept is the same as the electrostatic speaker; the only difference is the use of magnetism instead of electrostatic force to vibrate it. This results in a thinner speaker as well, without any protruding cone or large box.

On the flip side, these alternative technologies don’t do well with the low frequencies (bass), which is why traditional dynamic speakers are still the preferred variant.

Types of Speakers and Their Uses

While a speaker cone can technically produce any sound based on the electrical signal, its size determines the frequency range in which it performs optimally. For example, larger speakers are well-suited for low-frequency, bass sounds, distributing  them easily through an area.

On the other hand, smaller speaker cones can reproduce high-frequency sounds more accurately, although they have a narrow range and need to be placed accurately. This is why any good speaker you purchase actually consists of multiple speakers of different sizes, each specialized for a particular range of frequencies.

Common Speaker Types

Woofers are the types of speakers designed to produce lower frequencies, including a certain extent of bass as well as the human vocal range. This means woofers do the heavy lifting for any sound you reproduce, having the biggest contribution to the final sound you hear.

Tweeters are the smaller speakers designed to recreate  higher frequencies, including the sharp notes of instruments that we can barely hear, but still perceive as a richness of sound. These are often very directional, which is why surround systems often feature multiple tweeters.

Some manufacturers also include mid-range speakers that don’t quite fit either of these labels, but lie somewhere in between. These focus exclusively on the human vocal range, leaving both the higher and lower frequencies for other speaker types to handle.

There are also subwoofers that are typically found  in high-end audio systems. As their name suggests, these produce extremely low-frequency sounds that a woofer does not cover. Things like double bass or tremors are things that only a subwoofer can accurately reproduce. These types of speakers are massive, with a built-in amplifier to further push the slow but strong vibrations.

When to Use Different Speakers

Generally speaking, you don’t  need every type of speaker in every case. Your audio requirements differ based on the scenario, changing with the level of fidelity you want.

For example, office speakers aren’t meant to be entertainment powerhouses. As such, a powerful audio system with subwoofers for the deep bass is unnecessary. All you need are decent woofers to produce clear sound.

At home, on the other hand, you need quality speakers that can accurately reproduce musical performances, which means an audio system that includes both woofers and tweeters. This can mean opting for a great soundbar or a surround sound system, which would consist of both woofers and tweeters, either housed in the same enclosure or separately.

Then there are professional audio setups where the best performance is required. The bass is essential for larger venues (concerts or movie theaters), which call  for powerful subwoofers. This is how they recreate the thumping tremors of heavy bass or the sounds of explosions.

Speaker Placement and Acoustics

Speaker types and technical specifications impact audio quality but proper placement is also crucial.. This is because sound propagates as a wave, which means it can reflect, interfere with, and even combine based on the interactions with the physical space.

Placement Tips

Before you can place the speakers, you need to determine the listening position. And for the best results, the listening spot should be chosen carefully.

You should avoid both the halfway point in a room, and  a position right against a wall. Too much distance from the speakers is undesirable  as the bass frequencies don’t transmit effectively,while being seated with your ack to the wall creates distortions due to the reflected sound.

The ideal position is to be seated toward the front of the room, closer than the halfway point (the 38% rule, as it is called), with the speakers pointed toward you. Tweeters are especially directional and need to be angled correctly for the listener to get the complete effect.

The height is also important – the speakers should be placed at the height of a listener’s ears, and located  with some distance between them, angled toward the listening spot.

Related reading 📖: Speaker Coverage Patterns on AVIXA Xchange

Handling Acoustical Challenges

We discussed how speakers should be positioned, but sometimes the room layout itself raises challenges. The room may not be rectangular or perhaps it’s too small, causing reflected sound waves to interfere with the regular output.

This can be an issue for spaces with high ceilings as well (showrooms, auditoriums, or large halls), where the sound additionally reverberates after colliding with the roof. Or if the room layout is not rectangular, the side walls are more likely to contribute to echoes.

The solution? Sound-proofing. While hard, flat surfaces reflect sound, softer materials like fabric or foam can absorb the vibrations, preventing any unwanted reverberations. When  it is not possible to achieve the perfect angles for the speaker placement, it is a good idea to install acoustic boards on opposing surfaces to minimize reflections.

Best Practices for Getting Great Sound

Tuning and Adjustments

Tuning a speaker can be a complex process. It requires an audio analyzer, an understanding of the various audio parameters, and the knowledge to tweak these settings. Such in-depth tuning is beyond the scope of this guide.

But even as a beginner, there are some adjustments you can make to ensure the best performance from your speakers. A simple test is to run pink noise on your speakers individually and check for the response. If any of the speakers exhibit  distortion, or incorrect orientations (i.e., the left speaker playing on the right and so on), you need to check the connections.

You can also adjust the equalizer (EQ), but it is usually easier to adjust it on the application level rather than for individual speakers. Most audio systems these days come with built-in auto adjustments that take care of this technical aspect without requiring manual tuning.

Speaker Care and Maintenance

Like all electronics, maintaining your speakers involves keeping them free of dust. Speakers don’t  have moving parts like fans, but they do contain  metal connectors that carry the electrical signals, and dust or interference on them can introduce noise into the sound.

You also need to be careful when cleaning your speakers as you don’t want to make things worse. Liquids, for example, must be completely avoided. Pressurized air canisters are the best way to clean the internals, and you can always use a dry cloth for dusting off accessible  areas.

Aside from cleaning, keep heat in mind. The vibrating speaker cone also produces some heat as a by-product, especially in larger speakers with powerful woofers.

Always avoid placing your speakers in direct sunlight, and ensure adequate ventilation in the room to let the heat flow away naturally. Pay attention to the speaker’s placement; it should have some spacing around it on all sides for maximum airflow.

Troubleshooting Speaker Issues

Common Problems and Quick Fixes

If you’re running into audio issues with your speaker, it doesn’t necessarily mean it is broken and needs to be replaced. Often, it is a minor problem that you can fix on your own.

Nine times out of ten, the issue is with the connections. Switched polarities or loose wires are the source of a surprising number of audio problems. Always re-check your connections and tighten them before you look for other potential causes.

Electrical interference is also a possibility, though it’s rare. Most high-end speakers are well shielded against such interference, but the protection isn’t foolproof. Static noise can sometimes creep into your speaker’s audio output if speakers are placed too near a powerful electrical device, like a microwave. Make  sure your speakers are not in close proximity to electrical outlets or any other devices to minimize the chances of interference.

Summary and Key Takeaways

Understanding how speakers work is not essential, but it helps you make better choices when shopping for speakers. Factors such as  the size of its cone, the number of tweeters and woofers in it, and  even the volume of the  enclosure all influence the sound and quality of your experience. 

Tweeters, for example, handle  high-frequency response and are essential for appreciating any musical audio. Woofer size (and the speaker enclosure size) is an indication of the low-frequency response, or bass, as it is generally called. The best speakers balance both for accurate reproduction of a wide range of sound.

This knowledge also comes in handy for taking care of your speakers since many speaker components are magnetically and electrically sensitive. Even loose.  dusty connections, or nearby electrical interference can degrade performance over time

While we have only touched on a brief overview of basic speaker topics in this guide, here is a lot more to learn about how your audio equipment functions, proper speaker set up, tuning, calibration, and maintenance. . Continue your exploration on AVIXA Xchange, where you’ll find webinars, community discussions, and additional articles to deepen your understanding of speaker technology.

Explore more audio topics on AVIXA TV!

Photo credit: Getty Images/miodrag ignjatovic