High-res audio promises great sound quality at home and on the road, but what is really behind the new technology and when is the investment worthwhile for you? In this article, we’ll guide you on the differences between this and traditional music, which devices can play the new format and where you can buy the right music.
What is high-res audio?
The term “High-res Audio“ is not clearly defined in text books or online. The term refers to any resolution higher than a comercially available CD with a 16 bit and a 44.11 kHz.
On CDs, due to the relatively low sampling rate and bit depths, sounds with higher frequency than 22 kHz are lost. Mostly, files from 24 bits and 96 kHz are referred to as high-res audio files. This means they are less compressed and transport more information.
What determines the quality of audio files?
In order to convert an analog sound signal into a digital format, pulse code modulation is usually used. The quality of these recordings are determined by two factors – the bit depth and the sampling frquency.
The bit depth (also known as sampling depth) describes how long an analog signal can be converted into a digital one; typical sampling depths are 8, 12, 16, 24 or 32 bits. The higher the bit depth, the more dynamic the sound is and the more graduations are available between the loudest and flattest sound in a piece of music.
The component determines exactly how the individual tones can be reproduced, ensuring a particularly rich sound.
The sampling rate indicates how the music an be analysed for the digital conversation, meaning the number of times the sound is “measured“ per second. This value is approximately comparable with the picture frequency in video recordings.
The sampling rate of audio CS is at 44.1kHz (44,100 samples per second). This is sufficient to capture audio signals with frequencies of up to 22kHz, but sounds are lost.
High-resolution audio files, unlike CDs, have a much higher sampling rate and bit depth, which means they transport much more information than conventional MP3 formats. This also means that files require more disk space. A compressed audio file of four minutes is up to 30 megabytes, whereas an mp3 file is only 10 megabytes.
Comparing lossless and compressed audio files
There are many variations when it comes to lossless audio formats; the Free Lossless Audio Codec (FLAC), Direct Stream Digital (DSD), Monkey’s Audio (APE), Apple Lossless Audio Codec (ALAC) and the WavPack (WV/WVC). WAV formats can also represent the desired sampling depth and rate to be considered in high-res audio. Mp3 HD is a losseless audio codec, which contains lossless audio files, but still uses the file extension mp3. Therefore, they can be played back as normal mp3 by playback devices that do not support mp3 HD.
Uncompressed files give the sound a more clear, sharp and complex format in comparison to compressed formats, and are therefore closer to the original listening experience. Most sound recordings consist of natural tones (sounds from the real world) and this data is difficult to compress.
Computer-generated images can be compressed more easily than photographs, as photos contain complicated waveforms which are difficult to process with many compression algorithms. Audio samples change very quickly and only rarely are there sequences of equal bytes.
The quality of an audio file depends not only on the information, but also on how the files were mastered.
Crystal clear sound for music lovers
How exactly do the differences in compression affect the listener? With highly compressed files such as mp3, some information is lost. When playing the mp3 file, the decoder produces an analog sound signal.
This is no longer identical to the orginal signal, but sounds the same for most listeners as the original – provided the encoding, data rate of the transmission and quality of the amplifiers and loudspeakers is correct.
Sound components in very high and low frequent ranges are not reproduced or are completely discarded because most people do not perceive them or do very badly. This is called the psychoacoustic effect.
For music lovers however, the difference can be heard clearly. Anyone who has the opportunity to hear the same song as a conventional mp3 and then as a high-res audio format will recognise significant differences in sound quality. So, if you are looking for clear and complex sound, it’s worth investing in high-res audio. For classical music fans especially, the investment is worthwhile as classical music is particularly dynamic in its high and low range, and therefore benefits particularly from the higher audio quality.
High-res audio players and places to buy music
Many smartphones, tablets and mobile players do not support new high-res formats. Some new audio players are coming to the market which support high-res audio, but also provide enough space for their own music collection, for example Sony or Pioneer.
Music in high-res quality cannot be purchased at the moment from retailers such as Amazon or iTunes, but availability is growing.
A wide selection of high-res titles can be found at HIGHRESAUDIO, Technics Tracks and Acoustic Sounds. For mainstream music, it is worth visitng 7digital, Bleep, bandcamp or boomkat. Classical music fans can find a rich selection at CHANDOS, primphonic, CHANNEL CLASSICS and eclassical. Qobuz also provides a high-res streaming service.
photo credits: Fotolia, Nr, Fotograf
