Comparison Remax RB-T9 vs Samsung EO-MG920

— Mini-Jack (3.5 mm). Mini-Jack is one of the most popular wired connectors. However, it is not used in Bluetooth headsets, and it is extremely rare in other specialized accessories and predominantly is an auxiliary feature. So, in speakerphones, mini-Jack is usually responsible for connecting several devices to each other, and in car kits, for outputting sound to the radio or standard car acoustics. Note that in this case, the headphone jack is not considered a 3.5 mm jack, although it is most often performed in this format.

— USB A. The classic USB A computer connector, which is gradually being replaced by the USB-C connector. The meaning and application of this connection depends on the type of device. So, USB in speakerphones is a standard port for wired connection — both to computers and to specialized communication systems. And in Bluetooth headsets, this means that it is equipped with a USB adapter for connecting to a PC without a Bluetooth module.

— USB-C. A port similar in purpose to the one described above, but with a different, more modern, symmetrical shape that does not require specific connection, and correspondingly increased speeds.

— Bluetooth. Nowadays, Bluetooth is actually the standard interface for wirelessly connecting headsets and other audio accessories to gadgets. This technology is not only well suited for audio tra...nsmission, but can also be used for additional functions such as remote control. Features vary by version, the latest being Bluetooth v5. The communication range in this case can reach 10 m, and built-in Bluetooth modules are available in all modern smartphones, most phones, tablets and laptops, they can also be used in PCs and many other types of gadgets.

The range of sound that a headset or speakerphone (see "Device") can play through headphones or a speaker, and that the car kit can transmit to external speakers.

The frequency range perceived by the human ear averages from 16 Hz to 20 kHz. In a perfect case scenario, the sound device should also support the same range — this will provide the most complete sound without cutting off in frequencies. On the other hand, in order to reliably convey the human voice, a range of only 300 to 3400 Hz is sufficient. Therefore, if the device is planned to be used exclusively for voice communication, you can ignore this parameter. The mentioned 300 – 3400 Hz cover all modern models, and the extensive frequency range gives a not so noticeable gain in quality. But if you plan to listen to music, it is desirable that the specs of the device be as close as possible to the perfect 16 – 20,000 Hz; this is especially important for models with stereo support (see "Sound").

— Multipoint. A feature of Bluetooth devices (see "Connection") that allows them to connect to multiple signal sources at the same time. Thanks to this, it is possible, for example, to use one headset both for answering phone calls and for chatting via Skype on a laptop. However, some mobile phones (mostly devices with the simplest functionality, not smartphones) do not support this feature and are not able to work with a headset connected simultaneously to another gadget.

— Noise reduction. A feature that allows the headset microphone to "hear" only the necessary sounds (primarily speech) and filter out extraneous noise. The specific implementation of noise reduction can be different: some models provide an additional microphone that tracks noise and "cancels" it from the final signal, while others use purely software methods of sound cleaning. Anyway, such filtering significantly improves the audibility for the person at the other end of the line.

— Volume control. Own volume control built right into the device. Adjusting the sound in this way is usually more convenient than reaching into your pocket for your phone, changing settings on a laptop, etc. On the other hand, an additional control affects the compactness. Therefore, among Bluetooth headsets (see "Device") this feature is not always provided; but for speakerphones that do not have special restrictions on dimensions, it is alm...ost mandatory.

— Auto volume control. Automatically adjust the volume at which the device plays sound. Adjustment is usually carried out according to the level of ambient noise: in a quiet environment, the volume is reduced so as not to create discomfort, and in a noisy environment it is increased, ensuring normal hearing. Many models use the same microphone for auto-adjustment as noise canceling systems (see above), although this feature is not necessarily combined with noise canceling.

— Voice dialing. The ability to dial numbers by voice command, voiced into the microphone of the device. This feature is especially useful if you need to make a call, but reaching for the phone is undesirable or impossible — for example, when driving. Therefore, voice dialing is extremely popular in car kits (see "Device"), models without this feature are extremely rare. This feature is also supported by numerous Bluetooth headsets. However to use voice dialing, it must also be supported by the gadget to which the headset or car kit is connected; however, modern smartphones and tablets have no problems with this, difficulties can arise only with some models of classic mobile phones (non-smartphones). But language support in voice dialing needs to be specified separately: English is available in almost any model, but other languages are not so common.

— Microphone mute. The ability to temporarily mute the device's microphone — usually by pressing a special button. This will be useful in case you need to say something "to the side" and you do not want the person on the line to hear you. Note that the built-in microphone mute function is available in almost all mobile phones, as well as in most programs for voice communication like Skype. However, using the button on the headset is often more convenient than going into the settings of a smartphone or computer.

— A2DP profile. A Bluetooth connection feature (see "Connection") that allows stereo sound to be transmitted. A2DP support is by definition available on Bluetooth accessories that support stereo (see Audio). At the same time, this profile can also be provided in conventional one-ear headsets — it allows such a headset to normally reproduce sound originally recorded in stereo format (for example, podcasts or audio books), and is also used when headphones are connected (see below). Anyway, to use A2DP, it must be provided in both the accessory and the main device. Therefore, if you, for example, are looking for a headset for a simple phone that does not have A2DP, you can choose a model without this feature.

— AVRCP profile. Bluetooth connection feature (see "Connection"), which turns the accessory into a wireless remote control. To be more precise, we are talking primarily about managing audio and video players: start / pause playback, switch tracks, rewind, etc. At the same time, this feature can be provided even in Bluetooth headsets for one ear, which are not intended for music at all — for example, with such a headset you can control the music played from your smartphone through a portable speaker. Of course, AVRCP can only be used if both Bluetooth devices support it.

— NFC. NFC is a short-range wireless communication technology with a range of up to 10 cm. In Bluetooth accessories, the main purpose of this technology is to speed up the connection: instead of digging through the settings, just bring the accessory with NFC to a gadget that has the same chip (smartphone, tablet, etc.) and confirm the connection; and many gadgets allow you to configure and automatically connect when approached. There are other options for using NFC, but in this case they are practically not found.

— Display. Own display, which can show various service information: battery charge, volume level, connection indicator, etc. The specific capabilities of such a screen may vary depending on the type of accessory (see "Device"). However, most models with this feature are car kits — they can provide a fairly large screen with extensive information options, such as showing the number of an incoming or outgoing call. In headsets, screens are extremely rare: after all, most of the time the device is on the ear, out of the user's field of vision.

— Headphone jack. It's for connecting traditional headphones to the device. Most often, such a connector is a standard 3.5 mm mini-Jack, used in most modern headphones, which provides very extensive connection options. But the purpose and capabilities of this connector depend on the type of accessory (see "Device"). So, most models with this feature are speakerphones, and you can connect both regular headphones without a microphone, and wired headsets with their own microphone; both of them are used mainly to ensure the privacy of the conversation. But Bluetooth headsets are usually only compatible with headphones without microphones, and such headphones are used mainly for listening to music — you can talk privately on the phone using the headset itself.

The type of power used by the device. This parameter is indicated only for models with an independent power source: these are absolutely all Bluetooth headsets (see "Device"), as well as most speakerphones and some car kits (the last two varieties can also be powered from an external source — for example, from the on-board network of a vehicle or USB port).

Almost all self-powered devices run on built-in batteries, often non-removable ones. Such batteries can be made small and at the same time capacious, and their shape can be different — this makes it easy to integrate such a power source even into a miniature headset, not to mention larger accessories.

The capacity of the battery installed in the device (see "Power").

Theoretically, a higher battery capacity allows you to work longer on one charge. At the same time, the actual battery life will also depend on the power consumption of the device, and it is determined by a number of technical specs. Therefore, it is better to evaluate battery life not by battery capacity, but by directly claimed operating time (see below). It makes sense to use this parameter if the operating time is not specified; at the same time, it makes sense to make conclusions only if devices similar in specs differ in capacity — for example, 60 and 110 mAh.

Time of operation of the self-powered device (see "Power") on one battery charge.

Usually, the battery life in the talk mode is meant, when the device consumes the most energy. In headsets with high-capacity batteries, this battery life can be 9 hours or more. However, talking for several hours without pauses is almost impossible, so in fact the operating time is noticeably longer than in the specifications. So, a headset with an operating time of the same 9 hours is most likely quite enough for a 12-hour work shift, even if you have to constantly make calls through it; and if we are talking about only 5 – 6 calls per day, then the charge is guaranteed to last for several days, or even a week. At the same time, the difference in the claimed operating time is usually quite consistent with the difference in actual battery life, and it is quite possible to compare the real capabilities of different models by it.

The time it takes to fully charge the battery in powered headsets.

In this case, we mean the time it takes to charge the battery from 0 to 100% when using a standard charger (or a third-party charger with identical specs). Accordingly, this indicator may differ from the stated one, depending on the specifics of the situation. However, it is quite possible to evaluate different models using it, compare them with each other and choose a headset with fast charging.

We also note that increasing the battery capacity inevitably implies an increase in charging time. To compensate for this point, special fast charging technologies can be used. However, they affect the cost and require the use of specialized chargers.