Having obtained a respectable set of headphones last year, I started pondering about high definition music. Could I hear the difference between a track mixed at CD quality, 16 bit samples / 44.1kHz sample rate, and the same track mixed at a higher bit or sample rate? A number of artists have made HD audio releases available in a variety of formats, most of which are now obsolete (see: SACD, DVD-Audio) and/or hard to demux to something more modern. However some artists have made digital HD audio releases. The last two Nine Inch Nails records were released in HD and are more readily available.

These releases also had nice per-track embedded art

These releases also had nice per-track embedded art

"Ghosts Ⅰ-Ⅳ" had a standard-quality digital release but a high quality Blu-Ray release was also available, commercially. All versions were Creative Commons licensed, so people have legimitely demuxed the Blu Ray release and made it available in other formats. One was uploaded to archive.org, although it sadly lacks precise lineage information:

"The Slip" was released in HD audio digitally. However, I noticed that nobody had uploaded the HD release to archive.org, and having developed an interest in archiving, I did:

I tried performing some listening tests on my desktop computer, which has an M-Audio "Audiophile" 24/96 PCI sound card. However, in non-blind tests, I failed to distinguish the SD and HD versions of these songs. A friend suggested that despite the card's quoted rates, the signal-to-noise ratio was such that you wouldn't get high enough fidelity to play 24/96 properly. I can only take their word for it…

My preferred music player can only decode 16/44.1 but I recently learned that my phone, an Apple iPhone, can decode up to 24 bit, 48kHz. I decided to downsample the above two releases in order to try further listening tests on my phone. I uploaded both to archive.org:

So far in non-blind tests I have not noticed a particular difference. Whether it's my equipment, my ears, these particular tracks or whether HD audio being audibly better than CD quality is a myth, I am not sure yet.

I'm planning to do some proper ABX testing of various lossy codecs and bitrates prior to a major CD ripping exercise, so I may try proper ABX testing of HD audio at the same time.

(I'm collecting together past and future log posts about archiving under the tag 'archiving').