Standards
Various standards and special digital audio technologies that the sound card is officially compatible with. For example, the Dolby and DTS standards in various variations are used primarily for multi-channel audio tracks in films, while DirectSound and EAX provide high-quality “surround” sound in games. In fact, the ability to work with one or another standard is largely determined by the software part of the system, and not by the characteristics of the sound card; however, official compatibility means at least the full compliance of the card with the requirements of the standard and the minimum risk of conflicts at the hardware level.
Max. sampling rate
The highest sampling rate provided by the digital-to-analogue converter (DAC) of the audio card. For more details on the role of the DAC, see paragraph "Bit depth" above. Here we note that the quality of its work directly depends on the sampling frequency: the higher it is, the less distortion occurs when converting sound.
Usually in sound cards there are standard values for the maximum sampling rate:
44.1 kHz — corresponds to the sound quality of Audio CD;
48 kHz — DVD;
96 kHz — DVD-Audio 5.1;
192 kHz — DVD-Audio 2.0 (two-channel audio has a higher sampling rate than multi-channel audio for a number of reasons), the highest value in modern consumer-grade sound cards.
Another specific point is that the quality of sound played on a computer cannot be higher than the capabilities of a sound card. In other words, if an audio file is recorded at a higher sampling rate than the audio card can provide, its sound quality will be reduced: for example, on a 44.1 kHz card, even DVD-Audio sound will sound like an Audio CD. Therefore, if you want to fully enjoy high-quality sound, you should choose a model with a high sampling rate.
Signal-to-noise ratio
This parameter determines the ratio of the "clean" sound produced by the DAC at the output to all extraneous noise. As such, it is a pretty strong indicator of sound purity. According to the signal-to-noise ratio, DACs in modern sound cards can be divided as follows:
up to 90 dB — initial level;
90-100 dB — average level, advanced "home" models;
more than 100 dB — professional level.
Max. sampling rate
The highest sampling rate that the analogue-to-digital converter (ADC) of a sound card can provide when digitizing sound. Without going into details, we can say that the role of this parameter is almost completely similar to the bit depth described in the paragraph above. And its standard values, found in modern audio cards, correspond to the following sound quality indicators:
44.1 kHz — Audio CD;
48 kHz — DVD
96 kHz — DVD-Audio 5.1
192 kHz — DVD-Audio 2.0 (two-channel audio has a higher sampling rate than multi-channel audio for a number of reasons), the highest value in modern consumer-grade sound cards.
Signal-to-noise ratio
The signal-to-noise ratio provided by the analogue-to-digital converter (ADC) of the sound card in the processed signal. For more information about this ratio, see the paragraph of the same name above. Here we note that in domestic use it does not play a decisive role, but if you plan to record sound in good quality, you should choose a card with a high value of this indicator.
RCA
The number of inputs with RCA connectors in the design of the sound card.
The RCA connector itself can be used for different types of signal, however, in this case, the simplest linear interface for analogue audio transmission is meant. In such an interface, one connector allows you to transmit only one channel of sound. Therefore, the minimum and, in fact, the standard number of RCA inputs in modern sound cards is two, for the left and right stereo channels. A larger number is extremely rare, in separate high-end audio interfaces (see "Type"), but in such models the number of connectors is also a pair.
Separately, we note that this input should not be confused with coaxial S / P-DIF (see below): although the latter also uses an RCA jack, however, it is fundamentally different in signal format and has specific cable requirements.
Optical S/P-DIF
The number of optical S/P-DIF inputs in the design of the sound card.
S / P-DIF is a digital audio transmission standard with a fairly high bandwidth: in particular, it allows you to work with most multi-channel formats up to 7.1 inclusive. It is widely used in modern audio equipment, in particular, disc players and AV receivers. At the hardware level, S / P-DIF has two versions — with a coaxial connection (described below) and with an optical connection via a TOSLINK cable. The main advantage of the second option is complete insensitivity to electrical interference, because. light pulses are used to transmit information. On the other hand, an optical cable is quite fragile to bend and has limitations in length.
mini-Jack (3.5 mm)
The number of outputs with
3.5 mm mini-Jack connectors in the design of the sound card. It is this connector that is used by the vast majority of modern computer headphones and speakers of all price categories (although it is relatively rare in top-end technology), and it is very popular in other consumer-class audio devices. Therefore, almost all entry-level and mid-level sound cards have at least one 3.5 mm jack; the absence of such outputs is typical for specialized models (for example, DAC, see "View"). Also note that a single mini-jack output can work with a maximum of two channels, however, this interface is also used in multi-channel sound systems — in this case, the audio card is equipped with several connectors, each of which is responsible for its own part of the system. For example, for 5.1 systems, one connector is allocated to the centre, one to a pair of front channels, one to a pair of rear channels, and one to a subwoofer.
As with 3.5mm inputs (see above), this type of output can be used in a variety of ways and can even be configurable.
Jack (6.35 mm)
The number of outputs with
6.35 mm Jack connectors provided in the design of the sound card.
This connector is in many ways similar to the 3.5 mm mini-Jack described above (and is compatible with it through a simple adapter), but due to its larger size it is poorly suited for portable electronics. On the other hand, the 6.35 mm standard gives a more reliable connection with less chance of interference on the connectors; besides, it is possible to implement a balanced connection without any special difficulties (for more details about it, see "Balanced XLR"). Both are important in professional audio work. So the presence of such a connector, usually, indicates a rather high class sound card. But the specific specifics of using the Jack type output in different models can be different, these nuances should be clarified separately.
