Hi-Res Digital Master

Mastered for iTunes and beyond

The concept of what sounds "good" can be very subjective. Lossy compression is a compromise between sound quality and the file size limitations of digital music distribution platforms. Apple's Advanced Audio Coding methodology is a two-step process. The first step in the encoding path is to use state-of-the-art, mastering-quality Sample Rate Conversion (SRC) to resample the 24bit master file from 192kHz or 96kHz to a sample rate of 44.1kHz, but outputs it in a 32bit floating file. Because this SRC outputs a 32bit floating file, it can preserve values that might otherwise fall outside of the permitted amplitude range. Using a 32bit floating file prevents from happening any aliasing or clipping that could otherwise occur in SRC.

Step two is to take that 32bit floating file and encode it into 256 kbps AAC format without any additional dithering. This means that the encoder uses every bit of resolution available, preserving almost all dynamic range of a 24bit source file and eliminating the need for dithering. The advantage of this is twofold. Not only does it obviate the need of adding dither noise, it also lets the encoders work more efficiently as they don’t need to waste resources encoding this unwanted and unnecessary noise. By using this highly accurate file directly from SRC and taking advantage of its clean signal, the encoder can deliver the final product nearly as the artist intended it to sound. However lossy is not lossless. These original albums are no more available on iTunes or any other platform due to lack of Hi-Res quality distribution, despite high fidelity mastering conversion, just on Audiomack for the audition.

In addition to use of the latest Hi-Res Audio like Dolby TrueHD and DTS-HD Master Audio and now the classic DVD-Audio with Meridian Lossless Packing which is mathematical compression basis for Dolby TrueHD, I also experienced other formats in the past like MP3 5.1 Surround, MP3 SX (Stereo eXtended), MP3 HD (Lossless Audio CD quality), Dolby Surround 5.1 matrix encoded Audio CD, 44.1kHz 5.1 Dolby Digital CD, 88.2kHz Stereo or 44.1kHz 5.1 DTS Surround CD (5.1 Music Disc) and recently 2.8224MHz 1bit "DSD Disc Format" used in professional recorders from Korg, Tascam and others. Only the DSF format is supported and is a stereo-only, simplified form of DFF, the format used for Super Audio CD mastering and 5.1-channel downloads.