Impedance
Impedance refers to the headphone's nominal resistance to AC current, such as an audio signal.
Other things being equal, a higher impedance reduces distortion, but requires a more powerful amplifier — otherwise the headphones simply will not be able to produce sufficient volume. Thus, the choice of resistance depends primarily on which signal source you plan to connect the "ears". So, for a portable gadget (smartphone, pocket player), an indicator of
16 ohms or less is considered optimal,
17 – 32 ohms is not bad. Higher values —
33 – 64 ohms and
65 – 96 ohms — will require quite powerful amplifiers, like those used in computers and televisions. And models with a resistance of
96 – 250 ohms and
above are designed mainly for Hi-End audio equipment and professional use; for such cases, detailed recommendations for selection can be found in special sources.
Multipoint
A technology used in Bluetooth models (see "Connection") that allows the headphones to connect to multiple devices at the same time. Thanks to this, you can, for example, listen to music from a laptop, and when a call comes in on a mobile phone, switch the headphones to a conversation. This technology has its own characteristics for different manufacturers, and therefore, if the
multipoint function is critical for you, you should separately clarify the details of its operation in the selected model.
Voice assistant
Headphones with voice assistant support the user interaction with the device to a new level. The call of the
assistant. is carried out by pressing one of the control buttons on the headphones or by a specific voice command (for example, «Ok, Google» for the Google Assistant virtual apprentice). The assistant pauses playback, instantly changes the volume of the music, can notify the user of new alerts, helps to answer messages without the help of hands, and commands are given to the paired smartphone via voice control from the headphones.
Headphone search
The search function will come in handy if the headphones are missing somewhere and you cannot find them. It is implemented, as a rule, through a smartphone application. In the programme interface, just press the search button and both headphones will immediately start emitting a loud signal. The second option for implementing the
headphone search function is to track the last location of the headphones according to GPS satellites.
Headphone battery capacity
The capacity of the battery installed in the headphones of the corresponding design (see "Power").
Theoretically, a higher capacity allows to achieve greater battery life, but in fact, the operating time also depends on the power consumption of the headphones — and it can be very different, depending on the characteristics and design features. So this parameter is secondary, and when choosing it is worth paying attention not so much to the battery capacity, but to the directly claimed operating time (see below).
Operating time (music)
The declared operating time of headphones with autonomous power supply (see above) when listening to music on a single battery charge or a set of batteries.
As a rule, the characteristics indicate a certain average operating time in music listening mode, for standard conditions; in practice, it will depend on the intensity of use, volume level and other operating parameters, and in models with replaceable batteries - also on the quality of specific batteries. However, based on the stated time, you can fairly reliably assess the autonomy of the selected headphones and compare them with other models. As for specific values, relatively “short-lived” devices have a battery life
of up to 8 hours, a figure of
8 – 12 hours can be called quite good,
12 – 20 hours – very good, and in the most “long-lasting” headphones the operating time can
exceed 20 hours.
Operating time (no noise canceling)
How long does the active noise canceling headphones (see above) last on a single battery charge (or a set of batteries) when noise canceling is not used.
This function is quite “gluttonous” in terms of battery consumption, up to half of the total energy consumed by the headphones can go to its work. Thus, models with noise reduction can indicate both overall battery life (see "Operating time"), and battery life with the noise reduction turned off.
Operating time (with case)
The maximum operating time of TWS headphones, taking into account recharging with a native case. But this time is not continuous use, it takes into account breaks for "refueling". Anyway, this parameter allows you to understand for how long you can leave the network (for example, how many nights to spend in a tent to the accompaniment of your favorite artist).
Fast charge
The function reduces the charging time of the headphones compared to the duration of the standard procedure. For this, increased voltage and / or current strength is used, as well as a special "smart" process control. The capabilities and features of
fast charging may vary depending on the specific implementation of the technology. Most often, accelerated charging implies the possibility of literally 5-10 minutes. extend the battery life of the headphones in the accompanying charging case by at least one hour of additional playback.
