Hi-Res Audio. This little black and gold logo is starting to appear everywhere, both on the box of the latest headphones and on the home page of online music services. This is a sign that music is undergoing a new transformation. Do you need it?
The first real question to ask yourself is: is this really necessary? Because the added value is not often obvious.
Obviously, if you’re the type to cut sound waves into quarters, you’ll understand that high-resolution sound is not the same thing as lossless sound. In fact, many acoustic aesthetes turn their noses up at this encoding, which they associate more with marketing from certain streaming giants than with greater sound fidelity that you can actually hear.
These same aesthetes will still praise the merits of music in a lossless format.
High resolution and lossless
The problem is that high-resolution audio has become the ultimate in digital music over the past year. We find its label printed on the box of more high-end headphones. We also see the mention Hi-Res Audio clearly displayed on certain music services, such as the Tidal platform. The latter offers two levels of encoding: lossless (FLAC) and high-resolution lossless (Hi-Res FLAC).
The difference ? The encoding and sampling that define a lossless sound signal are the same as those obtained when playing a compact disc: 16-bit and 44.1 kilohertz. A high-resolution lossless sound signal, in addition to having a difficult-to-pronounce name, offers higher encoding levels: 24-bit and 192 kilohertz.
Now, recording professionals will tell you, unless you need all the frequencies in order to remaster an original soundtrack, the difference between the two sound formats is essentially inaudible. This is far from being comparable with the difference that exists between the good old MP3 format and these two much more generous sound formats.
For example, you will likely hear the sound of cymbals more clearly, and even be able to distinguish between different types of cymbals more easily, if you listen to a high-resolution or lossless music stream than if you listen to an MP3 stream.
More sound
What can be heard very clearly, however, is everything that high-resolution music streams include beyond musical notes and which is excluded from lower quality music formats. For example, stereophonic separation is better. This makes it possible to offer a spatialized sound format, what Apple simply calls its spatial audio, and which the rest of the industry has adopted under the Dolby Atmos standard.
This is another logo to watch out for on the box of your headphones if what you’re looking for is the pinnacle of current music technology: fully spatialized, high-resolution lossless audio. We can’t compress that, even less than its long name.
Nor can we reduce the price that must be paid to fully benefit from this musical format. Because lossless audio transmitted to cheap Bluetooth headphones is a huge waste of bits and kilohertz. The Bluetooth protocol only very recently added compatibility with high-resolution audio to its musical toolkit, via a codec called LDAC.
The promised maximum music stream is 32-bit at 96 kilohertz.
The right equipment?
In addition to the right sound source, you need hardware that can convert the digital stream losslessly into an analog sound signal. This specialized device is a DAC, as it is called in English.
Computers like Apple Macs have this digital analog decoder (in good French) integrated into their audio output (3.5 mm). Otherwise, you need to get one. It connects to the USB port of a computer or telephone, then via audio cable to headphones.
There are DACs of all formats and prices. The iFi brand offers, for example, the Go Bar, a $480 DAC, and its smaller brother, the Go Link, which costs only $100. The choice seems quite simple, given that the result in both cases is very satisfactory.
Manufacturers like Sony, for their part, offer certified Hi-Res Audio headphones, wired or wireless, starting at $300. Sennheiser, for its part, offers the HD660S2 ($550), a huge headset whose earpieces have an open back. Rather than a shell, each earphone is protected by a light metal mesh which offers no soundproofing, but which makes prolonged listening more pleasant.
The sound produced by their 38mm drivers is also more natural. The illusion of sitting in the recording studio with the musicians is greater.
That said, before paying more for any Hi-Res Audio certified headphones, remember that the only criterion required to comply with this certification is to be able to play music essentially coming from… a CD player. No need to pay a fortune — or fall into that other trap of modern marketing — for this.