Overview of types of headphone device on the market

Basic information

What does the diaphragm need to produce sound?

To convert the signals from the source into an audible sound, the diaphragm requires a magnet, a moving inductor, and a thin membrane. But with just these basic ingredients, we have so many different variations!

– Does the size affect the sound quality?

Many people mistakenly think that the larger the diaphragm, the better, but things are not simple!

It is true that the larger the diaphragm, the more superior physical properties there are to the small one, but it depends on many other factors that determine the sound quality.

– The more diaphragms, the better?

A pair of headphones usually have a frequency range of 20Hz – 20kHz. Some diaphragms can take care of this entire sound range; some can’t, so they must be used in ‘clusters’ of many pieces.

But just like the size, it’s not that more diaphragms mean better sound quality. Having multiple drivers also makes it more difficult to design a pair of headphones – when done well, the results are dramatic, but there are pros and cons when done poorly.

The most popular type of diaphragm at the moment: Dynamic

The diaphragm most used today in headphones, portable speakers, and large speakers are dynamic. This membrane type is very simple; it works by applying electricity to the inductor; the magnet will move at different frequencies by changing the current. The thin film will also move along and eventually produce sound.

This type of diaphragm has the advantage of bass because it can move a large amount of air to the listener’s ear, but on the contrary, it has the disadvantage that the distortion is greater than other types of the diaphragm. A good pair of Dynamic headphones need to reduce distortion and balance the bass with other components not to become the sole focus.

Advantages:

– Can produce powerful bass without much power

– Easy to make so that the cost can be very low

Defect

– Will distort at high volumes if not done well

– New star on the market: Balanced Armature

It is not as popular as Dynamic, but Balanced Armature (or BA) is also currently being used by many manufacturers because of its compact size and easier-to-design in-ear headphones.

This diaphragm type has a small bar (called Armature) wound by an inductor between two magnets. These two magnets control the position of the rod, and these moves lead to a thin film to produce sound.

This type of driver has the disadvantage of producing a good sound in all ranges, so it will be used in clusters of many (each is calibrated to produce a certain type of sound) or used add-in for Dynamic.

We have two advantages of BA. First, this type of driver can produce very good highs, with metallicity often outperforming Dynamic drivers. Second, BA can be placed in more closed headphones because it can operate without air, thereby increasing sound insulation.

Advantages

– Can be calibrated to create a certain tonal range (usually used as a high-pitched diaphragm for Dynamic)

– Greater detail, less distortion than Dynamic when properly calibrated

Defect

– Has a higher cost than Dynamic

– Weak in the bass range, need to be used in clusters to make this band good

Flat magnetic film

The flat magnet is a type of high-quality diaphragm, usually only found in Over-ear headphones. In terms of operating mechanism, this type of diaphragm is quite similar to the Dynamic membrane. Still, instead of having its inductor, the thin film itself will be moved by the magnetic field from the magnet.

Since the entire thin-film needs to be moved, a large amount of energy will be needed, making it necessary for pairs of planar magnetic headphones to have more magnets and larger power amps than usual. Therefore, the portability of these headphones will be very poor; users will only enjoy them at home.

The advantage of this diaphragm is that it has higher accuracy than Dynamic, thereby reducing distortion to the maximum. That is also the type of diaphragm that can produce good bass, but in return, the control is also better than most Dynamic drivers today.

Advantages

– Delivers generally high, detailed, and distortion-free sound quality

– Bass is strong and not distorted

Defect

– Must have a good Amp

– More expensive than Dynamic and BA drivers

– Bigger, heavier, and harder to manufacture

Electrostatic membrane

An electrostatic diaphragm is a complex diaphragm consisting of a thin (very thin) membrane that is electrically charged and two plates with opposing electrical currents (one negative and one positive) to move it from both sides. This type of diaphragm is difficult to manufacture, making the cost high and requiring a special Amp that is completely different from other types of diaphragm.

But perhaps you can guess, this type of diaphragm has great advantages: very high detail, reproducing the soundstage like real life. Of course, quality comes with the price; these pairs of headphones often cost thousands of dollars or more; the Stax SR009 pair, for example, costs no less than $4500!

Bone conduction membrane

As the name suggests, the bone conduction membrane transmits sound directly through the user’s bones to the eardrum without further passage of air. That is an effective type of diaphragm with open sports headphones, helping users both listen to music and hear outside noise to ensure their safety.

But in general, this type of diaphragm is more ‘handy’ than focusing on sound quality. Due to not transmitting sound directly, the detail of this type of diaphragm is not high, and the bass is weak; the brightness of the high range is also much reduced. Currently, there are still a small number of companies pursuing this type of diaphragm, but it cannot become popular.

Advantages

– Can be designed for users to hear outside noises

– Help deaf people hear the sound

Defect

– Poor sound quality

– Almost zero noise resistance

So which speaker is for you?

If you are looking for a pair of high-end mid-range and near-range headphones, up to 70% of choice will be Dynamic diaphragms. With the calibration ability of major brands, these pairs of headphones will still have very good sound quality 20% will be for BA-type headphones; most are used in clusters or support Dynamic.

But if you’re serious about sound quality, it’s entirely possible to find the remaining 10% as flat or electrostatic magnetic headphones. But keep in mind that these pairs of headphones will have a high price; moreover, we will have to spend a lot more money to buy a decent quality DAC/Amp!