How are, in fact, headphones made? We know a lot about headphones, don’t we? Be it for athletes, gamers, music enthusiasts, and even for home and office environments we know how to set them up and get the best out of them. We also know how to maintain them and prolong their lifespan. Used on a daily basis, for some of us they became like an extension of ourselves. But what is it that makes this nifty gadget that we also love? Let’s find out together!
A little bit of history
Let’s go back in time for a bit, somewhere (Somewhen?) around 1910. Don’t forget setting your filters to black and white, with a little bit of film grain. It is the beginning of telephony and radio technology. We needed a way of hearing audio signals, so some smart people invented electroacoustic transducers. What? Wait! Whoa. Yeah, they convert electrical signals to corresponding sounds. They were different from loudspeakers because a single user could listen to an audio source privately. Very important for early telephone operators and radio technicians. It was before amplifiers were even invented. Early earbuds they were. So what happens next? A creative guy named Nathaniel Baldwin goes to his kitchen (literally), gets creative and invents a first functional set, then sells it to the US Navy. So for a long time headphones were being used mostly by the military forces and industries. Some earbuds were even developed as hearing aids. But they did rise in popularity, and other people wanted to tune in. So fast forward about half a century, to 1958. (We can add a bit of color here.) An audiophile and a jazz musician (Who else?) named John C. Koss produced the very first stereo headphones. And after the transistor radio, which changed listening habits of people everywhere, headphones were the thing. The real deal. But our time machine is getting worn out, so let’s get back to 2018 fast.
Now that we know it isn’t magic what spurs them into reality, what is it? Well, if we were to break them down (which we hopefully won’t) and study the most basic of components, we would find some actually very common things. It is PVC, rubber, plastic, artificial leather, memory foam, copper and sometimes other metals too. The most common design is ‘against the ear’, meaning that those speakers are held by a piece of plastic, wrapped with foam and artificial leather, and made to bend around our heads. Crafty, eh?
Now that we know we have mini loudspeakers dangling over our ears every day, all day long, let’s check out the components. Here’s a short list:
- Case or covers. Back and front that neatly holds and covers everything so it can safely go into or over our ears. With neat cushions, so we don’t get sore ears.
- Rubber seal that holds the case together. (Wouldn’t want that falling apart.)
- Wires that usually carry the signal. With wireless headphones, it’s a little bit different as they use Bluetooth technology. (At least it’s not ‘infrared’. Do we still remember those days?)
- A big bulky magnet at the back of the speaker. This is why headphones get heavy.
- Coil, usually copper. It becomes an electromagnet when an electric current passes through it. Very cool. It’s the same thing used for guitar pickups (magnets).
- Transparent plastic cover/cone/diaphragm. It actually makes the sound when it vibrates.
- Each and every component is extremely sensitive. Even though it’s the 21st century, with all of our machines and technology, making a high-end headphone set requires skilled professionals and technicians.
We know about the materials, we know which components to make and use. So how does it all fit together?
Big molding machines mold most of the plastic components in accordance with the design of the model. A winding machine winds copper wire (as thin as a thread of human hair) around a cylinder. Standard is about ten thousand winds, but the more coils there are – better the magnet. In fact, this was done by hand in the past. After this process, it becomes a voice coil (electromagnet) which is then sealed, by a very skilled technician, with a transparent plastic cover (diaphragm). As for the seal, a tiny bit of glue and UV light is used. Other technicians will install that voice coil into a housing, which must be precisely positioned. A miniature loudspeaker like that is ready to undergo frequency range and distortion tests (with other factors of course). If everything checks out it is ready for the final assembly. Wires are installed in the strain relief of the adjustable band and corporate logos and other details are stamped on. Voila! Pack it up and move out! We can now feast on all those magnificent sounds. How cool is that?
We are headphone pros right now! They don’t say that knowledge is power for nothing. We have the history, materials, components and the process all under our belt. But there is only one thing that we failed to mention. When it comes to music, be it rock, classical, jazz, metal, rap, R’n’B or anything in existence, really, everyone will be a critic. See, opinions are not such a luxurious commodity, and everyone has at least one. “It is not best that we should all think alike.” Wise words of Mark Twain which convey much. How does this relate to headphones? Simple! Headphones allow us to crank up the volume to the absolute max! (Or as much as we want or can handle.) And we don’t have to worry about the negative feedback. After all, we cannot teach everyone what good music is. (We mean ‘disturb’ everyone. Pardon.) So we can now rest assured that regardless of the volume, our choice of music will only be ours. Enjoy the party!
The lesson is over and the class dismissed! What kind of music do you like to blast? How are headphones made is no longer a question, so what do you think about the process? Feel free to share your opinion in the comments!