Form factor
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Tabletop. Models whose housings are designed for self-installation. This may not necessarily be a table, but any suitable flat surface - for example, a shelf. This form factor is not only universal in terms of placement possibilities, but also extensive in the range of available offerings - it covers models from the budget class to the professional rank.
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Portable. Mobile solutions with basic switching capabilities and a minimum required set of connection connectors. Typically, portable audio interfaces are intended to be used in field, spartan, or cramped environments where equipment portability is at the forefront. Many of these models are designed to work together with a laptop and/or smartphone.
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Stand up. The housings of such audio interfaces are designed for installation in telecommunications racks: they are sized to fit a standard slot in the rack and a corresponding set of fasteners. The rack-mount form factor is typical for professional solutions designed for use in recording studios, concert halls and other similar places.
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Internal (built-in). Internal audio interfaces are usually connected to the computer's system bus and integrated into its hardware. In modern realities, embedded solutions are rare - they are inferior to external analogues in terms of mobility, ease of installation and the ability t
...o use on multiple devices. However, models with an internal form factor allow you to exchange data with a computer at the highest possible speeds and with the lowest possible latency rates.
It is also worth noting that some audio interfaces may have a combined design. In particular, the market offers universal models with both desktop installation and rack mounting options.Number of channels
The number of input and output channels that the audio interface is equipped with. See below for more details on each type.
— Input channels. Input (in) channels on audio interfaces designate the number of different audio signals a device can accept for recording overnight. Their number plays a decisive role in multi-channel sound recording, connecting several instruments or vocals at the same time. When choosing an audio interface, consider not only the number of input channels, but also the types of connectors (see “Inputs”).
— Output channels. Output channels output (out) is the number of audio signals that can be sent to other devices or equipment for playback. The outputs of the audio interface can be used to connect to amplifiers, monitors, speaker systems, headphones, etc. A large number of output channels will come in handy when creating sound mixes, multi-channel recording or multitasking in a studio environment. For simpler tasks, it is enough to have from 2 to 4 output channels. When choosing an audio interface, consider not only the number of output channels, but also the types of connectors (see “Outputs”).
Connection
Connection interfaces that the audio interface is equipped with.
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USB A. Connection via standard USB port. Until recently, this was the most popular interface for external peripherals, found in almost all PCs and laptops. Nowadays, it is often replaced by a USB type C port (see the corresponding paragraph). Most USB A audio interfaces draw power directly from the PC or other host device.
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USB type B. The connector has a characteristic square shape, noticeably different from the well-known rectangular USB A ports. In audio interfaces, it is used to transmit signals from external sources to a computer for recording and processing.
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USB type C. A peripheral connector with a symmetrical contact group, which often replaces full-size USB ports on board modern PCs and laptops. Many new models of audio interfaces are being made for this interface. An exception to the rule is individual instances for Thunderbolt. For them, it is Thunderbolt that is indicated, and not USB type C.
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Thunderbolt v2. Initially, Thunderbolt is a universal connector used primarily in Apple computer equipment. On board audio interfaces it is used as a general peripheral connector (similar to USB). This uses the miniDisplayPort hardware port. The data transfer speed in this version reaches 20 Gbit/s. Recently, the v2 edition has been rep
...laced by the Thunderbolt v3 version (see the corresponding paragraph).
- Thunderbolt v3. A universal interface that is found mainly in Apple technology. In audio interfaces it is used as a general peripheral connector (similar to USB). Specifically, Thunderbolt v3 provides data transfer speeds of up to 40 Gbps and uses a USB type C hardware connector (as opposed to earlier versions based on miniDisplayPort).
- Lightning. A connector used exclusively in Apple portable electronics (since 2012). Accordingly, audio interfaces with such a port are aimed at ease of connection to iPhones and iPads. Note that today there has been a transition from proprietary Lightning to the common USB type C - the latest generations of Apple gadgets are produced with just such a peripheral connection connector.
- mini-USB. A smaller version of the full-size USB interface, created for portable equipment. It is found very rarely in audio interfaces.
- FireWire. Universal connector, also known as IEEE 1394 or i-Link. In terms of functionality, it is analogous to USB, and in some characteristics it even surpasses it. However, FireWare is much less common. Used to connect to computers and some types of specialized audio equipment.
— Dante Dante connectors are used to connect audio interfaces to a network to transmit audio digitally. In this case, a standard Ethernet port (RJ-45) is used for physical access to the network.Preamplifier
The number of preamplifiers in the design of an audio interface, designed to work with a weak signal - which directly comes from a microphone, pickup, etc. Each preamp corresponds to one low-level input channel. For example, if an audio interface has four preamps, it can simultaneously process signals from four microphones or other devices connected to those preamps. Professional studio audio interfaces are often equipped with a large number of preamps to provide flexibility and the ability to record from a large number of sources simultaneously.
Total Jack / XLR audio inputs
— Total audio inputs Jack / XLR. The total number of analog audio inputs such as Jack (6.35 mm) and/or XLR (this interface can be combined with a “jack”). Note that such connectors can play the role of both a line input and a microphone or instrument input. For more details, see the relevant paragraphs.
— mini-Jack. The standard 3.5 mm mini-Jack is usually used in audio interfaces as an analog (line) input for two stereo channels, as well as as a microphone audio input (see the corresponding paragraphs).
Microphone
An input jack used to record audio from a microphone, which may transmit low signal levels and requires amplification. It often includes a microphone preamplifier - it amplifies a weak signal to a level that is suitable for recording or processing in an audio interface. The most common types of microphone inputs are:
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mini-Jack (3.5 mm). The standard mini-Jack audio connector (3.5 mm) provides average signal quality, which is why it is poorly suited for professional tasks such as studio recording. As a result, the “purely microphone” variety of the 3.5 mm jack is relatively rare, but still has a right to exist. It is also worth considering that microphones can use mini-Jack plugs for different numbers of contacts (from 2 to 4).
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Jack (6.35 mm). The shape and arrangement of contacts of Jack sockets (6.35 mm) are similar to the corresponding varieties of the 3.5 mm standard, but they are larger in size. Due to the larger contact area and less tendency to interference, plugs of this format are found in microphones of all price categories. In addition, a balanced connection is often made through the 6.35 mm jack - a special type of connection used in professional audio equipment that allows signal transmission even over fairly long wires without interference.
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XLR. In audio equipment, three-pin XLR connectors are most often used to connect a micropho
...ne. XLR provides a reliable and tight connection, and the interface sockets often have locks to secure the plugs. Connection through this connector is also carried out in a balanced way - using three wires instead of two. The peculiarity of this signal transmission is that external interference is filtered, in fact, by the wire itself, which allows you to transmit a high-quality audio signal even with long cable lengths. Often the XLR connector can be combined with Jack (6.35 mm).Line
The type of line input provided in the device. Uses the line input to feed audio from an external source to the audio interface.
The following types of connectors can be used for line input:
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mini-Jack (3.5 mm). A socket for a standard mini-Jack plug (3.5 mm). The connector serves as an audio input for two stereo channels. It is designed primarily for portable electronics such as smartphones, pocket players, etc. In stationary devices, Jack (6.35 mm), XLR and RCA are more popular.
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Jack (6.35 mm). A common audio connector for transmitting an analog signal. In design, this type of socket is as similar as possible to a mini-Jack (3.5 mm), but differs in size. Jack connector (6.5 mm) provides tight contact and is less susceptible to interference. It also supports a balanced connection - high-quality transmission of audio signals over fairly long wires with effective protection against interference.
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XLR. The XLR standard is considered professional - not only because of the high quality of signal transmission, but also because of its fairly large size and the presence of locks for securely securing the plugs. However, only one channel of audio can be transmitted over one cable, so XLR outputs are usually installed in pairs - based on stereo sound. Also note that these connectors can be combined with Jack sockets (6.35 mm). They also allow y
...ou to implement a connection in a balanced format with a high degree of noise immunity and the use of fairly long wires without affecting the frequency of the analog signal.
- RCA. Connector for coaxial cable with tulip type plug. The standard RCA input consists of two jacks - for stereo sound, left and right channel. One analog RCA connector can only transmit one channel of audio, so the number of such connectors corresponds to the number of channels supported by the device.Coaxial
Digital audio input for both stereo and multi-channel audio. The connector is RCA, but this input should not be confused with RCA inputs (see the corresponding paragraph).
The coaxial interface uses a fundamentally different signal format - all audio channels are transmitted through one connector, and even a special (shielded) cable must be used for such transmission. Compared to optical interface fiber (see above), this cable is more susceptible to electromagnetic interference, but less sensitive to damage.
Total Jack/XLR audio outputs
— Total audio outputs Jack / XLR. The total number of analog audio outputs such as Jack (6.35 mm) and/or XLR (this interface can be combined with a “jack”). Note that such connectors can play the role of both the Main output and the linear output. For more details, see the relevant paragraphs.
— mini-Jack. The standard 3.5 mm mini-Jack is usually used in audio interfaces as an analog (line) output for two stereo channels, as well as as an output for connecting headphones (see the corresponding paragraphs).