What Is High-Resolution Audio?

What Is High-Resolution Audio?

This week, Sony unleashed a battery of expensive audio gear that claims to support “high-resolution audio” which, like “ultra high-definition” in the video world, sounds pretty snazzy. But what does high-resolution audio mean? And will HRA really make the music sound better?

High-resolution audio is a new industry marketing term…

On Tuesday, the Consumer Electronic Association in partnership with Sony Electronics and Warner Music Group, Universal Music Group, and Sony Music announced a broad push for HRA. In the coming months leading up to CES, you should expect to hear a lot about the supposed benefits of HRA — and about the expensive hardware you’ll need to store massively huge high-resolution files and play them back.

Everybody wins if it catches on: Hardware manufacturers get to sell new specialised hardware, and the labels get to (try) to sell you their back catalogue all over again. And if the music sounds better at the end of all that, you might even win as well.

It’s worth noting that “high-resolution audio” is a bit of a misleading term because it implies a comparison with display resolution a la 1920 x 1080 video. Audio resolution corresponds to the number of bits per sample whereas the sampling rate corresponds to frequency response. Low-quality, compressed audio files might have the same sampling rate as HRA formats, so don’t get fooled.

…as a response to low-quality MP3s and earbuds…

The HRA push is all about making high-quality files as accessible and as universally supported as MP3s have been for more than a decade. The masses walking down the street listening to Mp3s through EarPods might be rocking out, but they’re listening to some of the worst audio quality in generations.

Neil Young has been one of the biggest proponents of the theory that CD-quality isn’t good enough. He even started a company called Pono that will sell high-resolution music files and a music player. Earlier this week, he announced that it would launch in early 2014. Young sums up the pro-HRA argument pretty succinctly:

There’s an awfully good chance you heard about a revolution we’re working on. Something that will significantly improve the way you get to hear and feel your favourite music.

Shocking you say? That perhaps the promise of “Perfect Sound Forever” propagated by the inventors of the Compact Disc was a bust? And that “CD Quality” promoted by the likes of iTunes and the creators of the MP3 was only an inkling of the flawed format they were hoping to emulate?

Both MP3s and EarPods are convenient and portable perversions of audio quality. MP3s are small files and EarPods are cheap, so we don’t mind that they suck. Indeed, most people — even you! — will notice a significant improvement in the sound reproduction by using either better hardware or better source files. And really, the better gear means nothing without better files. That’s where high-resolution comes in.

…which means higher-resolution audio than CD quality…

If the diagnosis of the iPod generation’s music problem is pretty straightforward, the solution isn’t a simple file type or a single piece of hardware. Unlike video’s Ultra HD, which denotes a specific image resolution, audio formats and resolutions adopted by audiophiles abound and so HRA doesn’t have a literal spec or definition. Here’s what the CEA said when I asked them for one.

CEA does not have a specific definition for high resolution audio. We may have a better sense of a definition as manufacturers and record labels make related announcements in the coming months.

The aforementioned major labels and Sony Electronics have agreed that HRA means “higher resolution” than two-channel 44.1 kHz/16-bit PCM audio. The audio sampling rate could be 48 kHz/16-bit or 192 kHz/24-bit. Sony’s new HRA hardware promises to support everything no matter what.

Lossy compression formats like MP3 don’t translate directly to this resolution language (more below), but as a point of comparison consider the respective bit rates — data transferred per unit of time — of a high-quality MP3s (320 kbps) and a CD quality (1411.2 kbps).

…that some people say sounds better than CDs…

There are legions of audiophiles who insist that even CD quality was a compromise. Rather than rip uncompressed or lossless audio from CDs, these enthusiasts want to go back to the source material and rip as much data as they possibly can out of it. Much like the people who yearn for the sound of vinyl records, these people insist there are perceivable differences between lossless 192 kHz/24-bit and 44.1 kHz/16-bit digital sources. People use adjectives like soundstage, texture, warmth to describe the difference. It’s all very subjective, but there are so many people who hear it, that the difference must be there right?

…while others disagree…

Objectively, CD quality is as good as it gets. People who think high-resolution audio is silly point out that it’s impossible for anything to sound better than CD quality. The CD’s 44.1 kHz sampling rate with 16-bit depth isn’t some random number devised by the Philips Corporation to ruin our ears.

Without going too deeply into the sampling theory behind how they came up with those numbers, suffice it to say that to human ears 44.1/16 audio is mathematically perfect sound reproduction.

Audio codec expert Monty Montgomery explained this at length last year when news broke about Neil Young’s plans to promote 192kHz/24-bit audio. He concludes:

Why push back against 24/192? Because it’s a solution to a problem that doesn’t exist, a business model based on willful ignorance and scamming people.

…and that could be a pain in the neck…

According to The Industry, we’re ready for HRA because storage space is so cheap and bandwidth so ample that we no longer need to settle for compressed file formats. Not so fast: These files are still huge and cumbersome. (Here’s a handy reference on file sizes.) To give you an idea, a 96 kHz/24-bit file takes up 34.56 MB is per minute compared to just 1.44 MB for a 192 kbps MP3. So take the library size at the bottom of your iTunes and multiply it by 24. That’s how much hard drive space you will need. Comparatively, CD-quality audio requires 10.84 MB per minute — about 7.5 times more than a good quality MP3.

Even if you shell out $US1000 for Sony’s new 500GB music player, and even if that’s enough space for all of your files, taking your music with you won’t be easy. seven hours of 96kHz high-resolution audio will fill up a 16 GB smartphone. As for modern conveniences like streaming music — -forget about it.

…but at least gives you options.

We won’t go as far as Montgomery, and in fact, there’s a good chance that the push for high-resolution audio is a good thing for your ears. HRA is overkill that nobody can afford — even if it really is better — but maybe its existence will make people aware of options within their reach. Good hardware and CD-quality source material is eminently affordable — just like it was 20 years ago