So, wireless Earbuds or wireless earphones, what are they? You can see them on the picture here. These weirdly shaped things plug into your ears and allow you to listen to any sounds that are streamed to them.
Let’s take a look at what is needed to produce some rocking music in your ear.
This is where it all starts. Music must be sent to your earbuds. The most used technology for this is Bluetooth right now. It uses very little energy and is available on almost any device. The audio information is compressed, because Bluetooth has not so much bandwidth. Kanoa uses a technique or protocol called AptX. If you have ever zipped files on a computer than you know that digital information can often be compressed. Mp3’s are the same kind of thing. The audio stream is compressed on your source device, sent through Bluetooth, received and decompressed in your earphones. So now you can listen to CD quality (better than 320 kBit Mp3) over a Bluetooth connection.
Digital to Analogue and Amplification
The digital music cannot be directly converted to actual sounds. First it needs to be turned into a signal that can drive the drivers. The electronics convert the bits of information into an analogue signal and supply the power to actually move air.
This is what makes the sound. You might have seen how speaker cones move and create sound waves. The drivers in in-ear headphones are the same. An electrical signal is fed to them from the amplifier and this is transformed into vibrations. The vibrations are transmitted by air to your ears. Two types of drivers are used in small earphones.
- Moving coil drivers (also called Dynamic): These are basically small versions of the cones used in speakers. The cone has suspension and a coil that is located inside a magnetic field. When current is applied to the coil, this leads to a force and subsequent movement of the cone. This technology has been around for a long time and has it’s limitations in efficiency and size.
- Balanced Armature drivers: These differ from dynamic drivers by the construction of the moving element. The coils don’t move like in the “moving coil” drivers. Instead they use a magnetic “armature” or spring like rod. It sits between two magnet poles. As you can imagine, the magnets attract the armature but it is centered by a spring. Around the armature sits a coil where the music signal is applied. This current leads to a change in the magnetization of the armature and then it is attracted to one of the magnet poles. The armature is connected by a little arm to a very light diaphragm which vibrates the air. Long story, hope you can kind of picture it. Balanced armature drivers are very efficient and great for higher frequency sounds. When they are used in numbers they can give great bass. The added benefit is that the bass remains very fast. These uses many high quality Balanced Armature drivers to give you great low and fast bass.
Housing and isolation
All the parts described above need a good housing. And this needs to fit snugly in your ear. Even with multiple balanced armature drivers the sound (especially the bass) loses power quickly. So the housing creates a closed space in your ear canal. Outside noise is automatically cancelled because of this. This is one of the reasons I like earbuds so much. You get inherent noise cancellation without the slightly weird sensation that active noise cancellation systems have.
Our ears are all a bit different. Most brands provide you with different plugs for the ear canal. Kanoa also provides three different shapes for the outside of the housing. This is very important because they are a bit heavier than most wired ones. If you get them to fit well, both in the ear canal and on the concha, you have almost zero change of losing them.
Another important characteristic of the housing is how sealed and strong it is. Kanoa wireless earbuds are rated for IP68. This means that:
- They can withstand powerful water jets from any direction. You can swim with them as long as you don’t dive too deep. They can withstand spray water all day long. So you can kite surf or wake board while listening to your favorite tunes. It also means that sweat will never be a problem.
- You can throw them on a hard concrete floor and in the worst case you get some scratches.
That is enough theory for now. Practical experience is coming soon.