Two weeks ago, after I posted an article on my purchase of the NuPrime uDSD DAC I cross-posted onto my personal Facebook page, and a good friend of mine basically replied that he did not understand half of the terms I described in the article, but was glad I was happy to get an upgrade.
That being said I wondered if there are those possible browsing here that knows anime and video games, but might not have knowledge in what Hi-Res/Rez is and would need a small jump-start on what it is. After trying to give my explanation to my relatives briefly on what Hi-Res audio is, and after what my friend said, I thought of making a quick list of terminology and definitions of what Hi-Res audio is.
At first I wanted make complete explanations of all the terms and such, but since there are many resources online (some I will link) on Hi-Res audio terminology I felt that it would be a disservice describing in much detail about Hi-Res Audio for both those who are well-acquainted with Hi-Res and those who are not.
Think of these as my TL;DR versions of the information:
- DAC: (Digital Audio Converter) A hardware device that decodes audio information from digital to analog. Digital audio is in binary and has no sound, analog is in sine wave. Sound cards are DACs.
- DSD: (Direct Stream Digital) A way to encode Audio into digital format differently than PCM audio. Many believe represents analog sound better than PCM audio. Wikipedia Entry
- PCM: (Pulse-Code Modulation) Most common way to encode audio into digital, what MP3s, FLAC, WAV, etc use. Depends on word-length and sample frequency (higher on either, more resolution) Think of it as using blocks to make a curve, the smaller blocks you have the more fine and closer to the curve you get. Wikipedia Entry
- Word Length: 16-bit, 24-bit, 32-bit (float), basically the higher the number the more information is put into re-creating the sine curve of audio. CD Audio and mp3’s are in 16-bit. Wikipedia Entry
- Sampling Frequency: Measured in kilo (and mega) Hertz, those 44.1kHz (Audio CDs) and 48kHz (common for audio used with video), how much samples are in each bit. Hi-Res audio has more per bit than standard CD quality. Wikipedia Entry
- WAV: (Waveform Audio File Format) Uncompressed audio file format, common to PCs. Has no metadata standard. Lossless. Wikipedia Entry
- FLAC: (Free Lossless Audio Codec) Lossless like WAV but reduces file size and adds standard metadata support. ALAC is similar but is invented by Apple. Wikipedia Entry
- Lossy Audio: MP3, AAC (used in iTunes), OGG, etc formats that highly compress audio into much smaller file sizes at the loss of certain frequencies. Audio-wise does not represent the audio exactly but approximates. Wikipedia Entry
- SACD: (Super Audio CD) Was going to be successor of CD, resolution is 1-bit, 2.8MHz DSD, but failed for mass market and only used by audiophile labels (only one factory exists now in the world). Hybrid SACD also has a CD layer so you can playback on a regular CD-player, but not the SACD layer. Wikipedia Entry
- DSF/DFF File formats for DSD audio. DSF holds metadata, DFF does not (older format).
I hope this covers the basics of Hi-Res Audio so far. I might make a Hi-Res Audio 102 if there is more questions.
Here are more links for more information if you are inclined:
- Sony’s Hi-Res page for info
- Crutchfield’s explanation
- Yamaha’s page on Word Length and Sampling Frequency
(This post was originally posted on June 22, 2015)