For all the talk around hi res audio on this site, we feel like we should start with some of the basics to explain what that actually means.
So, what is hi res music? What is loss-less music? What do you as a private consumer or audio professional need for hi res? And is it even necessary?
All good questions that we will try to shed some light on. Let’s start with the first one:
What is hi res audio technically?
Let’s briefly jump back a few decades to the beginnings of digital audio.
At this point we’ve already been able to listen to recordings of audio tracks for a long time, when the audio waves of the original where captured and transformed into indentations on vinyl disks. When a needle is dragged over those same indentations we were able to reproduce these sound waves – et voila, reproduced sound.
That was still analogue though. Just like a similar method to reproduce sound via magnetic strips on audio cassettes. But now usage of computers and other digital media was on the rise and we wanted to figure out a way to store and reproduce audio on systems that ran on 0s and 1s.
That meant we couldn’t store audio waves in their entirety as they came in. We had to start sampling many points of the audio curve in order to encode it to bits and bytes.
Let’s take the audio CD as a comparative basis, as that is the first medium that was widely used to store and distribute digital audio data and many of our readers probably grew up with them.
Audio CD quality was defined as audio data that was stored with 16-bit depth, 44.1 kHz sampling rate and 96 db sound pressure level.
Ah, there it was again! That word: sampling. The 44.1 kHz simply means that 44100 times per second we look at what relative numerical number on the graph of a sound curve we read and store those numbers.
What more could you want?
That sure sounds a lot, right? I mean, forty-four thousand times per second! How much more could you possibly need to reproduce an audio signal that is clean enough so that our brains can’t tell the difference anymore between the digital reproduction and the original?
Well, given a good audio CD that was recorded with quality equipment, the output quality is definitely nothing to sneeze at. After most of us enjoy listening to recordings of the same quality standard up to this day.
But of course technical standards have evolved. Now we have the Hi Res audio standard that upgrades the previously mentioned technical specs to 24-bit depth and sampling rates between 48 kHz and 192 kHz.
So simply put, many more thousand times per second we take readings of the audio waveform to smoothen out the resulting audio signal even more.
The bit number, by the way, means more or less how high or low a single sampled number can be, so it increases the detail of the reading.
Can you even hear that difference anymore?
Quite frankly, there are experts who say that you won’t hear a difference.
Just like there are people who claim that the human eye wouldn’t be able to see the difference between video displayed at 30 and 60 frames per second, or between HD and Ultra HD.
And maybe that holds true for you, but from personal experience I can tell you: No, 60 fps video looks way smoother to me, UHD makes a difference, and listening to hi res audio / music on proper equipment feels like a revelation. It sounds like the audio equivalent to switching a video from regular to HD quality.
What would I need to use Hi Res?
So, maybe you now want to try out the difference yourself. Or you already know that this is something you want. Then let’s talk about the equipment you need.
First of all you need to realize that you will always experience the lowest quality of all parts of the audio production chain.
We’re talking about the chain that starts with the artist in a room with microphones, mixers, and a lot of other equipment. It continues with the storage medium and format, and it ends with the amplifier and loudspeaker in your living room or directly in your ears.
The lowest quality of any single element of that chain will determine the resulting output quality. So obviously, the sound signal needed to be recorded in hi res. To transfer it to your system, it must not have been compressed, for example via MP3 format. And all equipment on your side needs to support hi res audio.
The simplest way is to look for the official hi res certification logo that’s widely used for professional and consumer electronics. That mean’s that piece of equipment was certified as “Hi Res ready“.
But be aware that this only means that digital hi res audio formats are supported.
That’s not everything! Of course there is more to the quality of a piece of equipment than the possibility to play a high resolution file format.
To make an exaggerated example, let’s say you were to plug some 30 dollar headphones into a 1000 dollar brand-name headphone amplifier. The resulting audio quality probably won’t be everything it could be. Even if both carry the above certification logo.
That’s why we spend so much time reviewing the specifics of all kinds of gear in our hi res audio reviews section.
What about sound sources?
Alright, now you have everything you need on your end. But where do you get music (for example) that was properly recorded in hi res? And how do you ensure it reaches your amp in the hi res quality?
If you’re using streaming services, that is generally a non-issue. You can go into Amazon Music for example and look for the “UHD” tag. If you click on it, you’ll be able to see some technical specs. Specs that you will now better understand, knowing what the bitrate and sampling rate actually mean.
But what if you want to locally store music files for hi res output? Well, normal audio CDs are right out. We talked about that.
Most end-consumers choose to download their hi res music from a diverse array of online shops. Here you will encounter a few different file formats. “FLAC” being the most common. This “Free Lossless Audio Codec” format compress audio waveforms without removing any sound quality.
It’s the upgraded version of it’s much older predecessor “WAV” and is both more space and resource efficient. Though still comparable in sound quality. So if you come across .wav files, those can contain hi res audio signals as well.
Another compatible format is “ALAC” which is basically the FLAC variant of the company Apple. So you’ll most likely see it being used by iTunes and the likes.
And what about the rest? If you have audio files in MP3, WMA, or M4A for example… Sorry, no. Those files are compressed by removing certain parts of the original audio and can never be hi res.
So, now you understand how hi res audio recordings differ from other lower quality sources and how to spot the difference from the technical specs. Mainly, look for the 24 bit label or a sampling rate of equal to or greater than 48 kHz.
You also know that all parts of your equipment have to be able to handle these high resolution signals. If they don’t than you’ll just get the sound quality of the lowest performing part of the chain.
We invite you to try out the difference between regular and hi res audio for yourself. See if you can’t hear a major improvement yourself. If you do, you might find out (like us) that you never want to go back. And if so, welcome to the audiophile life.