Speaker technology is the lifeblood of the audio industry, serving everything from your car’s audio system to the tiny Bluetooth headphones you use to listen to music. While most people don’t know the ins and outs of their design, knowing how they actually work can be the difference between buying the right speaker system or the wrong one, and is also extremely valuable when trying. to repair a speaker that is not working.
How do PC speakers work?
The fundamentals of speaker technology have not changed over the past 100 years, as has the usual TRSS connector (known as a jack). Edward Kellogg and Chester Rice’s 1924 dynamic loudspeaker is still the most widely used technology today, although there have obviously been advancements in technology and quality since then.
The fundamental principle of PC speaker technology is the transfer of energy from one state to another; To be more precise, transform the electrical waves that the PC sends to the speakers (and this can be extrapolated to any other audio reproducing device) into sound pressure waves in the air so that your ears can detect them.
The mechanism used to achieve this is quite simple: there is a cone in the speaker that vibrates, pushing and pulling the air to create the sound waves. The conversion of electrical energy into mechanical energy occurs through a combination of electromagnetic coils and a magnet attached to the cone; This coil moves the speaker cone back and forth as its electromagnetic field changes with the electric current flowing through it.
However, speakers require a lot more power to push and pull air in order to produce sound than electrons moving through the signal wire. Therefore, the speakers need an amplifier to drive the electrical signal sent from the PC at low power to a higher power state to drive the speakers. Modern solid state amplifiers increase the current to produce enough watts of power, while older tube amplifiers operate directly at high voltages.
Low power and home speakers always include a built-in amplifier, ensuring optimal power transfer to the speaker. However, more powerful hi-fi speakers often require an external amplifier, which requires special attention to power output and matching speaker impedance to ensure the setup works properly.
Tweeters and subwoofers
Obviously, not all speakers sound the same. An important factor in the sound of a speaker depends on the size of the coils: if you are wondering why a small in-ear headset or the Amazon Echo smart speaker sound “little” and lacking in punch, it is because they have a tiny driver that it can’t cover the long wavelengths needed for low frequencies, or it doesn’t have power in its amplifier to reproduce them without distortion.
There is a reason why the size of the speaker affects the frequency of the sounds it is capable of producing. Smaller speakers move easily and quickly without requiring too much power, making them ideal for high frequencies; Larger cones can move more air and spread out to cover longer wavelengths of lower frequencies, resulting in low distortion bass sounds. However, this makes them bigger and heavier, and they take longer to fully move, so they require more power. That’s why subwoofers are always big, heavy, and full of power.
In the most acceptable speaker setups you will find a combination of cone sizes combined with cross EQ circuits to filter the signal. So you can see big cones for powerful bass known as woofers until tweeters small for high frequency details. Larger home theater and hi-fi installations also often include an even larger low-frequency speaker called a subwoofer.
There is no exact correlation between the size and quality of specific frequencies. For example, tweeters come in a wide variety of types, from traditional cones and piezoelectric crystals, to ribbon cones and electrostatic diaphragm types.
The inner workings of the speakers
It is not only the size of the cone that affects the sound of the speakers, but all of its internal components can make a noticeable difference in the sound, including even the type of materials and the shape of the soundboard since sound is absorbed and reflected from the speaker body. The design of the passive radiator and port also contributes to the overall frequency response.
Each speaker is built with the following components:
- Diaphragm or cone: As in our body, it is the part responsible for the vibration and movement of air. This term is used interchangeably as a cone. Tweeter diaphragms can be made from thin ribbon, although polypropylene plastic is the most common material. Other materials include fiberglass, carbon fiber, aluminum, and PET plastic, which affect the weight and movement of the cone.
- Surroundings: Holds the diaphragm in place while allowing it to vibrate. The most common materials are rubber (rubber) and foam.
- Coil: a coil of wire connected to the rear of the diaphragm. The voice coil reacts to the magnetic field produced between it and the magnet when the current sent by the PC passes through it. This provides the force that moves the cone and produces the sound. The coils can hang above or below the magnetic material, which has advantages and disadvantages for coil mass, sensitivity and linearity of motion. Hanging coils tend to be reserved for high-end speakers.
- Magnet: This permanent magnet sits behind the speaker cone and interacts with the changing magnetic field to move the speaker. Different sizes and materials of magnets change tonal qualities slightly, and common materials include neodymium, ferrite, alnic, or cobalt samarium.
- Resonance table: a box, usually made of metal or wood, which contains all the components of the speakers mentioned above.
- Spider: it is placed between the diaphragm and the resonance box, ensuring that they do not touch each other.
Although the basic concept of speaker design is essentially the same in the vast majority of audio products, there are many variations in these internal components. The purpose of the product, the cost, and the material choices have a lot to do with the sound of the speakers.