In recent times, many manufacturers of audio products have begun to add Hi-Res products to their catalogs, an acronym that comes from the English «High-Resolution», and indicates that the device is ready to play the audio with it quality that has been recorded, which is synonymous with maximum fidelity. But what features does Hi-Res sound have and why is it different from normal audio?
What is the Hi-Res sound?
The sound that is recorded in the studios – whether music, cinema, dubbing or whatever – is raw audio, without compression, and the recording is done in an analog way, because as you know the sound is formed by waves . Logically, for this audio to be heard on our televisions, smartphones, consoles and others, it is necessary to convert it to digital, and for that to be possible we must first be able to measure the waves so that they can then be recreated in the device that is going To emit the sound.
To measure these waves, a series of periodic samples are taken, and this is what is called the sampling rate. This sampling rate cannot be infinitely, logically, but the higher, the greater the fidelity of the audio we are converting to digital, and that is why we set some scales or minimums for each quality.
Thus, for example, the audio sampling frequency of a normal music CD is 44.1 Khz, which means 44,100 samples are taken from the waves per second. For Hi-Res sound, the standard is set at 96 Khz, or 96,000 wave samples per second, so you will be collecting many more nuances of the original sound, being much more faithful to it.
Hi-Res sampling rate comparison
As for the sound we reproduce in our equipment, there is another factor to consider: compression.
The normal sound, when recorded, is done in a pure format and without compressing anything. But this type of sound has the disadvantage that the size of the files is very large, so it becomes complicated to store them in multimedia playback devices. This is especially true if we think that most users use our mobile or tablet to play audio files.
To reduce the size of these files, sound file compressors were created, such as the MP3 format, which try to give a more or less authentic approximation to the original sound source, but with a considerably smaller file size. For example, if an MP3 file with a compression of 256 kbps has a size of about 3 megabytes, that same file, without compressing, can have more than 30 MB.
What does Hi-Res sound bring to normal audio?
When the sound is compressed, or as we have seen when it is converted from analog to digital, many audio frequencies are lost, among which are many subtle details of the sound, which give it much more body. As we explained before, Hi-Res sound tries to get closer to the original audio, setting its quality standard with a sampling frequency and bit depth much higher than normal audio.
Currently, the Hi-Res sound formats that exist are: WAV, FLAC, ALAC, DSD and MQA. Of all of them, probably the best known for PC are the WAV format and the FLAC. The WAV format is usually used to record the original audios, but their files take up a lot of space because it is still uncompressed audio. The FLAC format is a type of compression that also falls within the Hi-Res sound quality and sufficiently compresses the sound source so that the loss of quality is absolutely minimized.
What do we need to hear Hi-Res sound?
Since the audio we will have in hand has certain special characteristics in terms of frequencies and formats, we will need an audio player that is capable of dealing with these compression formats, since not all players are capable of doing so. However, virtually any modern PC sound card, including those integrated into the boards, as well as many smartphones on the market (not televisions), are already capable of handling Hi-Res sound. According to the Japanese Audio Society, who created the Hi-Res audio standard, the DAC (the analog-to-digital converter) must be able to process audio at 96 KHz and 24 bit.
