The new LOAK2 and LOAK-PROTOTYPE also come in two types: closed-back and open-back. The only difference is whether there are holes in the rear housing (backplate) or not. Do you know how these affect the sound?
You might think that closed-back earphones, with the holes sealed, produce sound with high isolation and a closed-off feel, while open-back ones, with the holes open, offer a more open sound with weaker bass. However, this perception is based on appearance rather than reality.
Let’s take this opportunity to explain in detail.
Impact of Rear Housing on Sound.
In the case of dynamic driver earphones, I distinguish between the front housing, where the driver is installed, and the rear housing. The front housing is where the sound produced by the driver resonates, amplifies, and comes out of the nozzle.
On the other hand, the rear housing affects the movement of the driver’s diaphragm. Changes in the strength, speed, and size of the diaphragm’s movement result in changes in the sound emitted from the diaphragm.
Closed-Back
In the case of closed-back earphones, when the backplate is sealed, the compression and rebound forces of the air inside the rear housing due to the movement of the diaphragm become stronger. This makes the diaphragm move more forcefully and quickly.
When the diaphragm moves in this way, it tends to produce sharp, fast-paced, tight, and strong sounds. On the flip side, there is a tendency for peaks in the high frequencies, and frequencies above these peaks may be slightly masked.
Open-Back
In the case of open-back earphones, when the backplate is open, the compression and rebound forces of the air inside the rear housing due to the movement of the diaphragm escape to the outside through the open backplate. This weakens the compression-rebound force, resulting in smaller movements of the diaphragm compared to closed-back earphones.
With smaller and weaker movements of the diaphragm, the sound tends to be gentle and delicate, and peaks in the high frequencies are less likely compared to closed-back earphones. However, on the flip side, the sense of speed and power (impact) is weaker compared to closed-back earphones, and the sound may be slightly looser.
Low Frequencies in Closed-Back and Open-Back.
The difference between closed-back and open-back earphones is particularly noticeable in the low frequencies. Closed-back earphones produce tight low frequencies with a quick onset and convergence. The outline of the sound is clear, and it tends to have a slightly elastic quality. The attack and impact are also easily felt. However, the sound may feel restrained in terms of low-frequency volume due to its tight nature.
On the other hand, open-back earphones, compared to closed-back ones, tend to have a more relaxed feel with a wider range of low frequencies. The volume is there, but the low frequencies are more laid-back.
The choice between open and closed is not the sole determinant of sound; it is one element that influences the sound. Therefore, understanding these two types well and using them as a factor to judge what kind of sound suits your preference is recommended.