ABOUT DIGITAL AUDIO FORMATS
Today, there are several digital audio formats that are superior in quality to compact discs and are available on both physical media and the Internet. What are advanced sound lovers listening to now? Let’s find out.
The capabilities and quality of the CD-DA format were initially limited by the capabilities of CD as a medium. Legend has it that the standard 74-minute compact disc capacity was chosen in order to be able to record long classical pieces without splitting into two discs. And to be absolutely precise, this figure appeared thanks to Beethoven’s Ninth Symphony: it lasts exactly 74 minutes. Another default parameter was the 44.1 kHz sample rate. This figure defines the upper limit of the reproduced frequency range. For a CD that had to reproduce frequencies up to 20 kHz, this was the lowest possible carrier frequency. As a result, the only field of maneuver was the bit depth, the level of which was 16 bits. With regard to sound recording, bit depth determines its dynamic range and resolution.
The CD cannot be copied into the memory of the computer in the usual way, since we usually copy files. To save a CD-DA, you need a special program, a program that allows you to convert data recorded on an audio disc to PCM format (WAV file). A properly organized CD-DA ripping process allows you to get a completely identical digital copy on your hard drive. Audio CDs are generally saved on a computer as a large FLAC audio file (also WAV, WV, or APE) with a CUE index card or as separate tracks.
As the best digital audio format, the CD did not last that long, just over ten years. In the mid-nineties, the first format appeared that allows for better sound quality. HDCD was an improved version of CD-DA. Their difference consisted in a special recording algorithm that made it possible to save additional data on the sampling depth in a standard CD format. With an HDCD decoder, the output signal received not 16, but 20 bits, which did not give the standard of 96, but up to 120 dB of dynamic range and a very noticeable increase in recording resolution. At the same time, devices without an HDCD decoder played discs like normal CD-DAs. Interestingly, when saving such a disk on a PC in the same way,
The next leap in terms of sound quality came at the beginning of the new millennium. Two HD audio formats were introduced to the audiophile audience at once, appearing almost simultaneously. DVD-Audio, a further development of the traditional recording method and promoted by Panasonic and Toshiba. It is capable of recording 24-bit / 192 kHz in stereo mode and 24-bit / 96 kHz in multi-channel mode.
The SACD format competed with it, which, by the way, looked much less like a normal CD, although it was called “super CD”. Super Audio CD, developed by Sony, was based on the revolutionary DSD encoding algorithm. This digitizing method assumed one-bit sampling at an ultra-high frequency of 2.8224 MHz. The encoding and decoding principles of a DSD stream are much simpler than in high-bit formats and are essentially closer to the principles of analog technology. At the same time, the SACD format retains all the advantages of the advanced digital format and has output characteristics comparable to DVD-Audio in both sound quality and number of channels.
Both DVD-Audio and SACD were designed with a high level of copy protection, but inquisitive minds have already won over both formats, so if desired, the content of both disc types can be saved to a PC as images. ISO (without changing the structure and original codec) or FLAC tracks in 24-bit / 96 kHz or 24-bit / 192 kHz. Almost simultaneously with the DVD-Audio and SACD formats, another original format for publishing high-quality music was born: DAD 24/96. DAD stands for Digital Audio Disk, but it is essentially a DVD-Video with a high-quality still image and sound that can be played on any standard DVD player or PC.
Obviously, with this approach, Blu-ray media, with its HD sound formats, recorded in high quality without compression, is quite applicable for recording music in high quality. However, at the moment there are few such publications, and a special version of the BD-Audio format has every chance of not seeing the light of day, as the sale of high-quality audio material is already very active on the Internet. Anyone who does not want to convert DVD-Audio, DAD and SACD discs to the FLAC format on their own can officially buy albums already converted in 24-bit / 96 kHz or 24-bit / 192 kHz quality.
