Frequency range
The audio frequency range supported by the device. Most often we are talking about the range of frequencies that a device can produce in an analog audio output signal.
In general, the wider the frequency range, the fuller the sound, the lower the likelihood that the audio interface will “cut off” the upper or lower frequencies. However, it must be taken into account that the human ear is capable of hearing sounds at frequencies from 16 to 22,000 Hz, and the upper limit decreases with age. So from a practical point of view, it makes no sense to provide a wider range in audio technology. And the impressive numbers found in high-end devices are rather a “side effect” of advanced electronic circuits and are given in the specifications mainly for advertising purposes. Also remember that the overall sound quality is affected by many other factors besides frequency range.
MIDI in
Input for connecting MIDI devices: keyboards, turntables and other controllers. The MIDI stream does not represent sound, but service information for virtual musical instruments. Therefore, data received via
MIDI In is not processed by the device, but is simply transmitted to a computer, tablet or specialized equipment via USB type B, MIDI output or other similar connector.
Main
Through the Main outputs it is supposed to transmit signals from the audio interface to external devices for playing and recording sound. In everyday use, there are models with one type of Main connector, as well as with several varieties (for example, Jack (6.35 mm), XLR, RCA, or Jack (6.35 mm) / RCA, or Jack (6.35 mm) / XLR).
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Jack (6.35 mm). Output for transmitting analog audio signal. Structurally similar to the popular mini-Jack, but differs from it in its larger dimensions. As a result, Jack type plugs (6.35 mm) are used primarily in high-end stationary audio equipment. Outputs of this type usually operate on a “one channel per connector” principle (i.e., to transmit stereo sound you will need to use two Jack sockets). Also, this interface often provides a balanced connection - a connection in a special format that allows the use of long wires without compromising the signal quality (due to the suppression of interference in the wire itself). However, the Jack connection (6.35 mm) may also be unbalanced.
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XLR. Another type of output for transmitting an analog signal using a balanced connection. It allows the use of long cable lengths without compromising the quality of data exchange - external interference is absorbed directly in the cable. Often the connector is combined with a Jack interface (6.5 mm). The XLR is equipped with a locking lock and three contacts. A single three-pin an
...alog cable can only carry one channel of audio, so a standard XLR output typically consists of two jacks, stereo left and right.
- RCA. Jacks for coaxial cables with characteristic plugs, popularly known as “tulips”. One cable in analog format can transmit one channel of audio. The standard output of this type consists of two connectors - for the left and right stereo channels. On the other hand, RCA does not provide the possibility of a balanced connection, which is why it is inferior to other options in noise immunity, has noticeable limitations on cable length and is poorly suitable for professional use. Nevertheless, “tulips” have become very widespread in entry-level and mid-level stationary audio equipment.Line
The type of line output provided in the audio interface design. It outputs a line-level analog audio signal. This interface is mainly used for connecting recording devices, outputting a signal to playback equipment or to an external amplifier. And the types of connectors used for linear output can be as follows:
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mini-Jack (3.5 mm). A standard socket for the popular mini-Jack plug (3.5 mm), used as a line output. This connector is mainly used to connect some models of active speakers, while two stereo channels are usually output through one mini-Jack (3.5 mm). Note that headphone outputs, which also use a mini-Jack, are considered separately - see the corresponding paragraph.
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Jack (6.35 mm). A larger analogue of the mini-Jack connector (3.5 mm) for outputting an analog stereo signal. The Jack output provides a more reliable and noise-free connection, making it ideal for professional applications. Effective protection against interference is possible with a balanced connection method. To save space, the 6.35 mm output can be combined with an XLR connector (see the corresponding paragraph). The disadvantage of this design is the impossibility of using both interfaces simultaneously. Jack line outputs (6.35 mm) adhere to the “one channel per connector” principle.
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XLR. A round three-pin connector for outputting a line-level analog audio signal, oft
...en with a balanced connection type. Transmission is carried out over three wires instead of two, and during it the noise induced on the wire is eliminated. This allows the use of fairly long cables without compromising the “purity” of the signal, making this type of connection excellent for professional audio equipment. XLR is also considered a professional interface, both due to the ability to work with a balanced signal and due to increased reliability: such connectors are often equipped with locks to secure the plugs.
- RCA. Analog linear audio output using RCA connectors - so-called “tulips” (due to the characteristic shape of the plugs). The standard output of this type consists of two connectors - for the left and right stereo channels. Also note that RCA connectors can be used in other output interfaces, but they have their own names.MIDI out
Specialized output for transmitting MIDI commands. Found exclusively in audio interfaces that have a MIDI input. The corresponding signals represent a kind of “digital music notation”. The
MIDI Out connector is used to transmit MIDI commands received by the input to an external device - most often a hardware sequencer or other specialized equipment.
To monitors
Output connectors for connecting monitor speakers or headphones. Connecting monitors to the output of an audio interface allows musicians, sound designers, or sound engineers to monitor audio quality in real time. In audio interfaces,
monitor outputs can be made in various formats, but most often there are various combinations of RCA, XLR and Jack connectors (6.35 mm), less often - the classic mini-Jack (3.5 mm).
For podcasts / streams
Audio interfaces designed for
recording podcasts and conducting live broadcasts on the Internet (streams). They are supposed to connect streamer and podcasting equipment such as microphones and headphones, and the functions in such models include fine sound adjustments, adjusting the balance between different audio sources, etc.
Loopback
The
Loopback function allows you to combine the signal from connected microphones, instruments and other line-level sources with background music, audio tracks and other sounds played on the connected equipment (usually a computer). Loopback will come in handy when recording virtual instruments, podcasts, streaming, etc.
USB
Number and type of USB ports in the device. Most often, audio interfaces contain full-size USB A connectors, and their number can vary from 1 to 3 pcs. Such ports are being replaced in modern models by more compact USB type C, which allows the plug to be inserted in either direction. Somewhat less commonly, audio interfaces can be equipped with USB B ports, while desktop models can be equipped with microUSB connectors.