4/1/20 - Zoro Staff
From the tiny earbuds you slip in your ears to drown out the world, to the massive stacks of speakers at a heavy-metal outdoor concert, audio speakers are practically everywhere. They have a wide range of industrial and commercial applications, and anywhere audio is playing there's a speaker behind it.
Other than knowing that sound comes from a speaker, you probably never really gave much thought as to what they actually are and how they really work. This article will provide insight into the components of a speaker and how they interact to provide the audio you hear.
Technically, a speaker is an electroacoustic transducer, or a device that converts electrical audio signals into sound. Today, the most common speaker type is the dynamic speaker, which was invented in 1924. While there are about a dozen components that comprise a modern speaker, the 4 main ones are the permanent field magnet, voice coil, suspension, and the diaphragm or cone, which is typically conical shaped.
For many people, a common use for speakers is to hook them up to a stereo to listen to music. When hooked up and powered on, electrical signals feed through the speaker wires into the voice coil, turning the coil into a temporary electromagnet. As the electricity flows back and forth in the speaker cables, the electromagnet repels or attracts the permanent field magnet at the back of the speaker. The repelling and attracting of the field magnet causes the voice coil to move forward and backward, which in turn moves the diaphragm, or cone, back and forth pushing on air to create sound waves.
The cone is typically made from paper, plastic, fabric, or lightweight metal. It needs to be light enough for it to be able to respond to the vibrating, pulsating movement to create the sound waves, and durable and stable enough to avoid sound distortion. Helping the cone to operate effectively is the "spider" (or suspension) in the speaker. It's a flexible, corrugated support designed to hold the voice cone in position so it can move back and forth freely.
The cone will move farther and generate a louder noise when a bigger pulse of electricity is sent into a speaker. Smaller pulses of electricity result in quieter sounds. When the cone vibrates a large amount, speakers will play loudly. Conversely, when it moves only a small amount it will play softly.
In addition to the importance of these key components in the makeup of the speaker, the enclosure in which it's housed is almost nearly as important. The design and the material of the enclosure should be as non-resonant and stiff as possible to eliminate the chance of the speaker reverberating, which obviously has a significant impact on the quality of sound generated by it. In instances where high fidelity sound is desired, the enclosures will likely have multiple speaker transducers to handle the broad range of frequencies. In this case, these individual transducers are considered drivers and the entire enclosed unit is then referred to as the speaker.
The drivers designed for reproducing low audio frequencies are called woofers, mid-range drivers are designed for middle frequencies, and drivers for reproducing high audio frequencies are called tweeters. Smaller speakers are found in a wide variety of common, everyday products like TVs, computers, cell phones, and more, while larger speaker systems are used in concert halls and theaters, stadiums, and public address systems, to name a few.
A speaker that needs to produce extremely high frequencies incorporates the use of a piezoelectric transducer. Rather than utilizing the more common magnetic coil setup, it's based on vibrating crystals. They're typically referred to as crystal speakers or simply "buzzers." You're familiar with them as they're used to produce that loud, piercing sound commonly heard from smoke alarms. In this instance, the sound quality being produced isn't as important as the effectiveness of the sound to alert people to a potentially dangerous situation.
Whether being used to listen to your favorite tunes or hearing the message in the grocery store that a clean-up is needed in aisle 5, speakers are everywhere as part of everyday life, and can help keep you entertained as well as informed.
Product Compliance and Suitability
The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand and follow all manufacturer instructions.