To this date, there are currently 3 categories of headphones available on the market. This article will help you to filter out the category that you would be most interested in.
The categories are:
Orthodynamic / Isodynamic Headphones
The three categories are based on the type of technology used to produce sound from the headphones. The difference is the type of converter principle used to convert electrical signals into sound waves.
1) Dynamic headphones
Dynamic headphones use a moving coil driver. A moving coil driver simply means that there is a magnet in headphones that produces a static magnetic field. A voice coil attached to a membrane is placed in the magnetic field and a current passes through the voice coil, which causes the membrane to vibrate and produce sound waves.
Most dynamic headphones need some power for it to work. Because of this, most headphones on the market are dynamic headphones. These are used by regular music listeners, musicians and professional studio mixers. The most popular manufacturers in the music industry that produce dynamic headphones, including Sony, Beyer, Sennheiser, Grado and Audio-Technica. They can cost $ 8 or $ 800 US dollars (USD) upwards and may be wired or wireless, outdoor or closed, earplugs or study quality.
The benefits of dynamic headphones are that they are widely available and are usually cheaper to orthodynamic and electrostatic. Because some power is needed to power them, most of them will work with portable devices and computers without the need for a headphone amplifier. A headphone amplifier is a miniature power amplifier specially designed to power the small speakers in the headphones.
The disadvantages are that orthodynamic and electrostatic headphones can beat them in terms of speed and clarity.
Dynamic headphones are the best headphones for the first time because of their cost and wide range.
Orthodynamic / Isodynamic Headphones
Orthodynamic headphones were very popular throughout the 1970's. They are considered by some to be old technology but have a revival now.
Manufacturers include Audeze, Fostex, Hifiman, Kenwood and Dual.
Orthodynamic headphones have flat and larger voice coils that cover the membrane. This means that the current is better distributed on the membrane, which in turn produces sound waves. Larger voice coils mean larger membranes (even larger than electrostatic headphones), which means that more power is needed to power them.
The advantages of orthodynamic headphones are that they provide excellent response and sound quality that resembles an electrostatic.
Disadvantages of orthodynamic headphones are that they are generally larger and require a headphone amplifier to drive them so that they are not portable. They are also generally more expensive than dynamic headphones.
Electrostatic headphones have drivers that do not have a voice coil. The diaphragm is instead charged with electricity. The diaphragm is located between two electrically charged metal plates (electrodes) that are perforated. As the membrane vibrates, air is forced through the perforated metal plates that produce a sound wave.
Electrostatic headphones are usually more expensive than dynamic headphones and are relatively unusual. Because of the diaphragm and two metal plates, which need to be charged with electricity, the headphones need a large amount of electricity to run. The amount is so much that normal amps that drive dynamic and / or orthodynamic headphones just will not cut it. A dedicated headphone amplifier is needed, which often requires electrical potentials in the range of 100 to 1000 volts.
The thin membrane, which is only a few microns thick, makes it possible to produce a frequency response that extends well above the earpiece of about 20 kHz. In other words, higher clarity and sound quality are produced.
Akg and Stax produce electrostatic headphones.
Advantages of electrostatic headphones are the sound quality and clarity of which they are known.
Disadvantages of electrostatic headphones are that they are expensive, requiring the owner to buy a special amplifier to drive them and they lack bass. There is a lack of slam / impact compared with dynamic headphones.