Cable length
The length of the cable supplied with the headphones with the appropriate connectivity.
The optimal cable length depends on the planned format of the "ears". So, for pocket gadgets,
1 metre or less is often enough, for a computer it is already desirable to have a wire for
1 – 2 m, and preferably
2 – 3 m. And models with a longer cable length —
3 – 5 m or even
more — are mainly designed for specific tasks, such as connecting to a TV or using in recording studios.
Recall that in some models the cable is removable (see below) and can be replaced if necessary with a longer or shorter one. Also note that there are extension cables that allow you to increase the length of the main wire; such a cable may even be included in the delivery, this point (and the length of the additional cable) is usually specified in the notes.
Harmonic distortion coefficient
The coefficient of harmonic distortion produced by this model of headphones.
This parameter determines the amount of non-linear distortion introduced by the headphones into the reproduced sound. The lower it is, the less such distortions, the cleaner and closer to the original sound is. So, an indicator of 1% or more can be considered tolerable at best, from 0.5% to 1% — good, less than 0.5% — excellent (such indicators are acceptable even for monitor headphones), and less than 0.1% — almost perfect.
Note that a low harmonic coefficient in itself does not guarantee high-quality sound — a lot depends on other features of the headphones, primarily the frequency response.
Waterproof
The headphones have special protection against moisture and dust; also, this clause may specify the level of such protection according to the IP standard.
Not all
waterproof headphones allow complete immersion in water, but in this case this is usually not required — water protection is mainly intended for safe operation in the rain (or during sports activities when the user sweats a lot). But the specific degree of such protection in different models can vary markedly, and here it is most convenient to evaluate it by IP marking. This marking consists of the letters IP and two numbers; moisture resistance is described by the second, last digit, and in modern headphones you can find the following options:
— 2. Protection against vertical drops of water in the working position and when the device deviates up to 15 ° from this position. The minimum indicator that allows us to talk about resistance to rain (however, without strong winds).
— 3. Protection against splashes falling vertically or at an angle up to 60° from the vertical. Provides resistance to moderate rain and strong winds.
—
4. Splash proof from any direction. With such headphones, rain of medium intensity is not terrible, regardless of the strength of the wind.
—
5. Protected against water jets from any direction. Allows you to transfer already a combination of strong wind w
...ith a downpour.
— 6. Protection against strong water jets. It is considered the minimum level that allows you to swim safely (with your head above the surface of the water) wearing headphones.
— 7. Possibility of short-term (less than half an hour) immersion under water to a shallow depth (less than 1 m); continuous operation in immersed mode is not expected. In such headphones, you can no longer only swim, but also dive under water to a shallow depth (plunge with your head), but they are not suitable for full-fledged diving.
— 8. The highest level of water protection actually found in modern headphones (although theoretically there is a higher level, level 9). Allows long-term (more than 30 minutes) immersion under water to a depth of 1 m or more, and even permanent work in a submerged position. And although the latter is not particularly relevant for headphones, however, this degree of protection makes it possible to swim and even dive safely. However, note that specific restrictions on use in such headphones may be different, they must be clarified according to the instructions.
As for protection against dust (it is indicated by the first digit in the IP marking), its level in modern “ears” is indicated mainly in cases where it corresponds to level 4 (protection against objects 1 mm thick or more), 5 (allowed a small amount of dust that does not affect the operation of the device) or 6 (complete protection against dust). Also note that this number can be replaced by the letter "X" — for example, IPX7; this means that no official dust certification has been carried out for this model. However, this resistance in many cases can be assessed by the degree of protection against moisture: for example, devices with a moisture resistance of 7 or 8, by definition, do not let water through — which means that they are also not afraid of dust.Weight
The total weight of the headphones; for true wireless models (see "Cable Type"), the weight of each individual earbud is listed.
This parameter is directly related to the design (see above) and some features of the functionality. Thus, the mentioned true wireless devices are very light, their weight
does not exceed 25 g. More traditional in-ears and in-ears can be noticeably heavier,
up to 50g for in-ears and up
to 100g for most in-ears. Overhead models, for the most part, are quite massive: among them there are many models weighing
200 – 250 g,
250 – 300 g and even
more than 300 g. It should be noted that a significant weight for false ears is often not a disadvantage, but an advantage: it allows them to stay on the head more securely, creates an impression of solidity and reliability, and most often does not create significant inconvenience.