High Resolution Audio, or Hi-Res Audio, is the most exciting technological leap digital audio has had in years. Between all of us here at Wolf Audio Systems, we have lived through the age of vinyl, 8 track, cassette, CD, SACD, MP3’s, FLAC and now 24 Bit audio and DSD. There is a lot of chatter out on the web, good, bad and indifferent about whether Hi-Res Audio (HRA) is worth it, and in short, when done right – it is! You don’t have to be an audiophile with a $100k system to hear the difference. Even a decent pair of headphones and the Cub can show you a whole new side of the music you’ve known all your life.
But what is Hi-Resolution audio? It is audio that has a higher bit depth and sampling frequency than CD audio. That means more data and samples per second than the standard 1,411kbps (kilobits per second) of CDs. CDs are 16 Bits of audio sampled 44,100 times per second. In technical parlance CDs are 16/44.1Khz. That will be important further on…
The CD format had limitations from the start. In terms of bits and bytes, to truly digitize ALL of the music of a recording master, the size of that album would be many, many gigabytes… CDs have 700MB (megabytes). To the executives and marketers, the CD standard was a great, reliable new medium, a chance to resell all the music once again after the cassette boom. So what did the audio engineers have to do to keep selling albums? Compromise. They compromised by compressing the music, by cutting down on the high and low frequencies, reducing the amount of audio information available to the listener.
Digital audio, when viewed through a scope looks jagged. Analog audio is smoother. The better the digital mastering, the closer the audio wave form looks to the original analog source. And that is what this is all about. Perfect reproduction of music, the way the creators and masterers intended it. The audio equipment community will never stop trying to move that target forward, and that is a very good thing for the listeners.
Eventually the SACD and DVD mediums raised that tiny space constraint and gave engineers some more room to make an album sound like they really wanted it to sound, but there were still some constraints and limitations to everything they could have done. But now, thanks to file based audio, we have been freed from the constraints of any physical medium. Hard drives are Terabytes in size, and there are albums that are over 5GB, eight times more information per second than a CD. With a 2TB drive, you can store hundreds, even thousands of albums.
There is a wide standard for determining what is HRA, and there are several formats, bit depths and sample rates that can be considered HRA and is offered for sale. High-resolution audio is defined as: “Lossless audio that is capable of reproducing the full range of sound from recordings that have been mastered from better than CD quality music sources.”
And there are also four different Master Quality Recording categories that have been released in order to describe the recording that has been made from the “best quality music source” available.
The four descriptors are:
MQ-P: from a PCM master source 48kHz/20-bit or higher – typically 96/24 or 192/24 content
MQ-A: from an analogue master source
MQ-C: from a CD master source (44.1kHz/16-bit)
and MQ-D: from a DSD/DSF master source – typically 2.8MHz or 5.6MHz content
A good source to read more about this can be found at What HiFi?
And now there is DSD…
We’ll be discussing DSD Audio in the next post, so stay tuned…