Comparison Sony MDR-XB650BT vs Sony MDR-ZX330BT

The specific connection interface provided in the headphones. At the same time, some models may provide several options at once - these are either combined devices (see "Type of connection"), or wired headphones equipped with additional adapters or replaceable cables, or wireless devices connected via a radio channel or infrared port (in the latter case the characteristics additionally specify the method of connecting the complete adapter).

- micro-Jack (2.5 mm). A wired connector similar to the popular 3.5mm mini-Jack (see below), but smaller. Equipment with such a connection is rare - mostly these are miniature devices, where there is simply no room for a 3.5 mm jack. Accordingly, this interface has not received distribution among headphones either: it is almost never found in its pure form, models with such a plug are usually supplemented with an adapter or cable for mini-Jack.

- mini-Jack(3.5 mm). Perhaps the most popular modern type of audio connector; if a device has a headphone output, it is most likely a 3.5 mm jack. Accordingly, most headphones with a wired connection use this type of connector. It is worth noting that headphones with a microphone designed for such a connection are equipped with a special plug for a combined headphone + microphone audio jack (such connectors are popular in portable gadgets and laptops). But with a socket designed only for “ears” without a microphone, such a plug may not work cor...rectly. An alternative would be headphones equipped with two separate mini-jack plugs; see below for more details on this option.

- mini-Jack (2 x 3.5 mm). Models with two 3.5 mm mini-jack plugs. This option is guaranteed to mean that we are not talking about classic headphones, but about a headset with a microphone: one plug is used for headphones, the second for a microphone. Such models are convenient when used with equipment that has separate 3.5 mm jacks for “ears” and a microphone - for example, for a PC.

- Pentaconn (4.4 mm). It is a 5-pin balanced output. Pentaconn uses a larger than the mini-Jack plug, its size is 4.4 mm, it is stronger and more reliable than the 3.5 mm connection. The Pentaconn's balanced connection makes it possible to handle higher power audio signals. Thanks to this connection, it is possible to transmit a signal over a fairly long distance. Accordingly, such a connector is relevant for headphones of the highest category.

- Jack (6.35 mm). The largest type of Jack type audio connector found in modern technology. Outputs of this type are found mainly in stationary audio equipment - they are too bulky for portable devices, it is easier to use a 3.5 mm mini-jack there. At the same time, a 6.35 mm jack is considered to be a more suitable interface for professional and audiophile-class equipment: it provides a more reliable connection, greater contact density and, accordingly, less likelihood of interference. Therefore, although relatively few headphones are equipped with their own Jack type connector (mostly premium solutions), many models with a 3.5 mm mini-Jack plug are equipped with a 6.35 mm adapter.

— XLR. A characteristic round connector with a lock-lock and 3 contacts (there are other options in quantity). As a rule, it is used to transmit an analog signal through a balanced connection. This connection provides high resistance to interference, typical for professional applications; at the same time, the plug itself has rather large dimensions. In view of all this, the presence of XLR is relevant mainly for headphones designed for use with advanced stationary equipment.

— Bluetooth. The most popular wireless connection option in today's headphones. This is due to the fact that built-in Bluetooth modules are available in almost any modern smartphone, tablet or laptop, and appropriate adapters can be produced for devices without this module (for example, a PC). True, the sound quality with a traditional Bluetooth connection is relatively low, but special technologies such as aptX and aptxHD are increasingly being used to remedy the situation (see "Codec Support").
It is also worth noting that Bluetooth modules can correspond to different versions (the latest for 2022 is Bluetooth 5.0, Bluetooth 5.1, Bluetooth 5.2 and Bluetooth 5.3) this moment does not affect the sound quality, however, it determines a number of additional nuances - the range and reliability of communication, the ability to work through walls and other obstacles, resistance to interference, etc. In modern "ears" you can find the following versions of Bluetooth:

• Bluetooth v4.0. An update in which the capabilities of version 3.0 (classic + high-speed Bluetooth) were supplemented with a third format - Bluetooth LE (low energy). This communication standard is intended mainly for the transmission of small amounts of information - in particular, service data packets to maintain a connection. At the same time, the creators managed to combine economical energy consumption and a long communication range - it can reach 100 m. This has a positive effect on the stability of the connection.
• Bluetooth v 4.1. Development and improvement of Bluetooth 4.0. Speaking specifically about headphones, the key innovation for them in this version was improved noise immunity when working near devices with 4G (LTE) mobile communication devices (in earlier standards, Bluetooth and LTE signals could overlap, which led to failures). So for use with a 4G smartphone, headphones with Bluetooth support of at least v 4.1 are definitely recommended.
• Bluetooth v4.2. Further, after 4.1, the development of the Bluetooth standard, which mainly introduced a number of general improvements in reliability and noise immunity.
• Bluetooth v5.0. Massive Bluetooth update released in 2016. One of the most notable innovations was the introduction of two additional Bluetooth LE operating modes: high speed mode (due to reduced range) and extended range mode (due to reduced speed). In the case of headphones, the main significance of these innovations is to improve the overall reliability of the connection, increase its range and reduce the number of gaps.
• Bluetooth v 5.1. Update version v 5.0, which, in addition to general improvements in the quality and reliability of communication, has such an interesting feature as determining the direction from which the Bluetooth signal is coming. Thanks to this, a smartphone or other gadget that supports this standard is able to determine the location of connected devices with an accuracy of up to a centimeter; this can be useful, for example, to search for lost sight, but still working headphones.
• Bluetooth v5.2. The next, after 5.1, is the Bluetooth 5th generation update. The main innovations in this version are a number of security improvements, additional power optimization in LE mode, and a new audio signal format for synchronized parallel playback on multiple devices.
• Bluetooth v5.3 was introduced at the dawn of 2022. Among the innovations, it accelerated the process of negotiating the communication channel between the controller and the device, implemented the function of quickly switching between the state of operation in a small duty cycle and high-speed mode, improved the throughput and stability of the connection by reducing the susceptibility to interference. In case of unexpected interference in the Low Energy mode of operation, the procedure for selecting a communication channel for switching is now accelerated.

- Radio channel. A wireless radio connection that does not use Bluetooth technology (see above). Such headphones are usually equipped with an adapter that connects to the signal source by wire - for example, via USB or mini-Jack 3.5. This connection method is more versatile than Bluetooth, it can be used even with devices that do not have wireless modules. In addition, the radio channel provides a long range (often up to several tens of meters), and the sound quality is quite high even without the use of special technologies. The disadvantage of this option is the actual presence of an adapter, which is not always appropriate: for example, it is easier to use Bluetooth headphones with a tablet or smartphone.

- IR channel. Another method of wireless connection, a feature of which is that it does not use radio waves, but infrared radiation. Theoretically, the advantage of such a connection is resistance to electromagnetic interference, the disadvantage is that it only works in the line of sight. In practice, the situation is such that in most cases it is easier to use Bluetooth or a radio channel for a wireless connection. So this option is found only in specialized devices for equipment equipped with its own IR outputs - in particular, among headphones for car monitors.

— USB A. Wired connection to a standard (full dimensions) USB connector. This option is found exclusively among headphones designed for computers / laptops or gaming consoles. One of its advantages is that sound via USB is transmitted digitally and is processed not by the computer's audio card, but by the built-in headphone converter; such a converter often provides better sound quality than the said audio card. In addition, multi-channel audio can be transmitted via a USB connection - this point will be especially appreciated by gamers. Another advantage is that when using USB-headphones, specialized audio outputs remain free, and you can connect other equipment to them - for example, computer speakers or a vibrocap.

— USB-C. A relatively new type of USB connector, used in both desktop computers and portable devices - as the heir to microUSB. It does not differ much in dimensions, but it has a more advanced design - in particular, it is made double-sided, which makes it easier to connect. Most often complemented by other connection options (they can be both wired and wireless).

— Lightning. A universal connector used in Apple portable equipment - iPhone smartphones and iPad tablets - since 2012. Not used by other manufacturers. Accordingly, models with such an interface are designed specifically for "apple" technology (primarily iPhone and iPod touch players). This type of connection is especially relevant given the fact that in the latest iPhones, the manufacturer has completely abandoned a separate audio output, and the only way to connect headphones is the Lightning port.

- Corporate outlet. A connection connector that is not related to generally accepted standards and is used to a limited extent in the equipment of one or more manufacturers. Such connectors are found mainly among headphones for mobile phones. However, in connection with the general standardization, this option has practically disappeared from the scene. Theoretically, the proprietary connector is also the Lightning described above, but it is separated into a separate category due to the popularity of Apple technology.

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.

Rated headphone sensitivity. Technically, this is the volume at which they sound when a certain standard signal from the amplifier is connected to them. Thus, sensitivity is one of the parameters that determine the overall volume of the headphones: the higher it is, the louder the sound will be with the same input signal level and other things being equal. However, we must not forget that the volume level also depends on the resistance (impedance, see above); moreover, it is worth choosing “ears” for a specific device first by impedance, and only then by sensitivity. In this case, one parameter can be compensated for by another: for example, a model with high resistance and high sensitivity can work even on a relatively weak amplifier.

As for specific figures, headphones with indicators of 100 dB or less are designed mainly for use in a quiet environment (in some similar models, the sensitivity does not exceed 90 dB). For use on the street, in transport and other similar conditions, it is desirable to have more sensitive headphones — about 101 – 105 dB, or even 110 dB. And in some models, this figure can reach 116 – 120 dB. and even more.

It is also worth noting that this parameter is relevant only for a wired connection according to the analogue standard — for example, via a 3.5 mm mini-...jack. When using digital interfaces like USB and wireless channels like Bluetooth, the sound is processed in the built-in headphone converter, and if you plan to mainly use this kind of application, you can not pay much attention to sensitivity.

Codecs and additional audio processing technologies supported by Bluetooth headphones (see “Connection”). Initially, sound transmission via Bluetooth involves fairly strong signal compression; This is not critical when transmitting speech, but can greatly spoil the impression when listening to music. To eliminate this shortcoming, various technologies are used, in particular aptX, aptX HD, aptX Low Latency, aptX Adaptive, AAC, LDAC and LHDC. Of course, to use any of the technologies, it must be supported not only by the “ears”, but also by the Bluetooth device with which they are used. Here are the main features of each option:

- aptX. A Bluetooth codec designed to significantly improve the quality of audio transmitted over Bluetooth. According to the creators, it allows you to achieve quality comparable to Audio CD (16-bits/44.1kHz). The benefits of aptX are most noticeable when listening to high-quality content (such as lossless formats), but even on regular MP3 it can provide a noticeable sound improvement.

- aptX HD. Development and improvement of the original aptX, allowing for sound purity comparable to Hi-Res audio (24-bits/48kHz). As in the original, the benefits of aptX HD are noticeable mainly on high-quality...audio, although this codec will not be out of place for MP3.

- aptX Low Latency. A specific version of aptX described above, designed not so much to improve sound quality, but to reduce delays in signal transmission. Such delays inevitably occur when working via Bluetooth; They are not critical for listening to music, but when watching videos or playing games, there may be a noticeable desynchronization between the image and sound. The aptX LL codec eliminates this phenomenon, reducing latency to 32 ms - such a difference is imperceptible to human perception (although for serious tasks like studio audio work it is still too high). aptX LL support is found mainly in gaming headphones.

- aptX Adaptive. Further development of aptX; actually combines the capabilities of aptX HD and aptX Low Latency, but is not limited to this. One of the main features of this standard is the so-called adaptive bitrate: the codec automatically adjusts the actual data transfer rate based on the characteristics of the broadcast content (music, game audio, voice communications, etc.) and the congestion of the frequencies used. This, in particular, helps reduce energy consumption and increase communication reliability; and special algorithms allow you to broadcast sound quality comparable to aptX HD (24 bits/48 kHz), using much less transmitted data. And the minimum data transfer latency (at the aptX LL level) makes this codec excellent for games and movies.

- A.A.C. A Bluetooth codec used primarily in portable Apple gadgets. In terms of capabilities, it is noticeably inferior to more advanced standards like aptX or LDAC: the sound quality when using AAC is comparable to an average MP3 file. However, for listening to the same MP3s, this is quite enough; the difference becomes noticeable only on more advanced formats. AAC hardware requirements are low, and its support in headphones is inexpensive.

— LDAC. Sony's proprietary Bluetooth codec. It surpasses even aptX HD in terms of bandwidth and potential sound quality, providing performance at the Hi-Res level of 24-bits/96kHz audio; there is even an opinion that this is the maximum quality that it makes sense to provide in wireless headphones - further improvement will simply be imperceptible to the human ear. On the other hand, supporting this standard is not cheap, and there are still quite a few gadgets with such support - these are, in particular, Sony smartphones, as well as mid- and high-end devices running Android 8.0 Oreo and later versions.

- LHDC. LHDC (Low latency High-Definition audio Codec) is a high-definition, low-latency codec developed by the Hi-Res Wireless Audio Alliance and Savitech. In the vast majority of cases, its support is implemented at the hardware level in Huawei and Xiaomi smartphones. The codec is also known as HWA (Hi-Res Wireless Audio). When using LHDC, signal transmission from the phone to the headphones is carried out with a bits rate of up to 900 kbps, a bits depth of up to 24 bits and a sampling frequency of up to 96 kHz. This ensures a stable and reliable communication with reduced latency. The codec is optimally suited for high-end wireless headphones and advanced digital audio formats.

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.

Among the equipment, it is worth highlighting silicone and polyurethane tips, relevant for in-ear headphones, additional fixation nozzles and behind-the- ear arms for better attachment in the ear, interchangeable ear pads, additional cable, dongle, aircraft adapter, case / case and docking station. There are also other accessories. More details about them:

- Silicone tips. Replaceable silicone tips used in in-ear headphones. Usually, several nozzles of different sizes are supplied in the kit, which allows you to adjust the headphones to a specific user. The practical advantages of silicone are softness, durability, general convenience and at the same time low cost.

- Polyurethane nozzles. Replacement tips for in-ear headphones made of foamed polyurethane. This material is somewhat more expensive than silicone, it requires regular cleaning and has a shorter service life - including due to deformation as it wears. On the other hand, polyurethane is ideal in terms of acoustics; it is these tips that are considered the best choice for lovers of in-ear “ears” with high-quality sound.

- Ear hooks. Removable devic...es designed to additionally secure each earpiece to the ear. Note that such devices should not be confused with behind-the-ear mounts (see above). The main difference is that the arms are used exclusively in some models of in-ear headphones and earbuds as an additional option. In other words, you can wear such headphones without a bow, while the behind-the-ear mount is usually made non-removable and, in principle, you can’t do without it.

— Nozzles of additional fixation. Auxiliary caps for a tighter fit of the in-ear headphones. They are used to provide better fixation of headphones during sports or provide additional volume to users with a large auricle.

- Replaceable ear pads. Comes with interchangeable ear tips. In general, the ear pads are the part with which the headphones come into contact with the listener's ears. In full-size and on-ear headphones, they are soft pads on the inside of the cups.

— Case (case) / cover. Covers are usually called soft rag bags, they protect the "ears" mainly from pollution and take up a minimum of space. Cases are made of hard materials, they are a little more bulky, but they protect well from shock, pressure and contact with sharp objects. In any case, the complete case or case is optimally suited for the headphones and is more convenient than an impromptu protective casing.

- Charging case. Case - a case made of hard material - simultaneously playing the role of a charger. This feature is very popular on true wireless models (see "Cable Type"). The charging case usually has its own battery and the headphones are already charged from this battery; this design provides additional convenience in several moments at once. Firstly, the case, in fact, also performs the function of a power bank - an autonomous power source; the capacity of such a “power bank” may be different, but it is usually enough for several full charges of the “ears” (for more details, see “Capacity of the case”). Secondly, the ability to charge the headphones directly in the case reduces the risk of losing them. Thirdly, the charging procedure itself is quite convenient - just connect the cable to the case.

- Dock station. Stationary stand with the possibility of placing headphones and contacts for charging them. Also, docking stations are often used to transfer the sound track to headphones - they are connected directly to the sound source via a wire, and the sound is transmitted to the ears wirelessly within a certain radius of action.

— Clip for carrying. A clip designed to fasten the wire to a pocket, collar, lapel of clothing, etc. It provides additional convenience: thanks to the clip, the wire does not hang out, the likelihood of touching it with careless movement or catching on the surrounding object is reduced.

- Additional cable. An additional cable provided in addition to the main one may have different features and specializations. So, complete cables can vary in length, connector type, wire type, additional equipment (microphone, volume control), etc. These details should be specified separately in each case. Here, we note that almost all headphones with this configuration have a detachable cable (it makes sense to supplement a non-detachable wire with an extension cable, and it is considered a separate accessory - see below).

- Extension. A type of additional cable designed solely to increase the overall length of the wire. Due to the extension cord, you can adjust the headphones to the specifics of the situation: for example, “build up” the cable if you need to switch from a laptop to a TV or a stationary audio system.

— Airplane adapter. Dedicated headphone adapter for use with modern airliner entertainment systems. In such systems, a special way of connecting headphones is used - through two 3.5 mm jacks (and we are talking about classic "ears", without a microphone). Models with a traditional single 3.5 mm plug can only be connected to this output through an adapter; such adapters may initially be included in the delivery.

- Windproof microphone. Devices in the form of a foam rubber or "shaggy" lining on the headphone microphone capsule. Cut off unnecessary ambient noise and minimize the effect of direct exposure to air currents on the microphone, which can cause interference in speech transmission.

— Dongle. The dongle is used to simplify the organization of connecting wireless headphones to other devices. In fact, this is a radio transmitter (less often a Bluetooth transmitter) that non-contactly broadcasts sound to headphones from a connected device.

This list is not exhaustive and may include other optional items.