What is hi-res audio and do you actually need it?

What exactly is hi-res audio?

Hi-res audio is a term that describes digital music files that have better sound quality than CDs or MP3s. You might wonder what makes hi-res audio different from other formats. It actually has to do with how the sound is recorded and stored in the file.

When sound is recorded, it is converted into digital data by measuring the sound wave at regular intervals. This is called sampling. The more samples you take per second, the more accurate the digital representation of the sound will be. This is called the sampling rate, and it is measured in kilohertz (kHz). CD-quality audio has a sampling rate of 44.1kHz, which means it takes 44,100 samples per second. Hi-res audio typically has a sampling rate of 96kHz or higher, which means it captures more details of the sound wave.

Another factor that affects the sound quality is the bit depth, which is the number of bits used to store each sample. CD-quality audio has a bit depth of 16 bits. Compare that to Apple Music’s bit depth of 24-bit audio, with sample rates ranging from 48kHz to 192kHz.

What’s the difference between hi-res and lossless audio?

Before we proceed, there’s something that needs to be cleared first to gain a better understanding of how hi-res audio works and what you need to experience it. The terms hi-res audio and lossless audio may be used interchangeably by some, but they refer to different things.

Here is a simple analogy to help you understand. Imagine you have a painting of a landscape. Hi-res audio is like having a high-resolution photo of the painting, where you can see every brushstroke and detail. Lossless audio is like having a copy of the painting that is exactly the same as the original, without any distortion or damage. Both hi-res and lossless audio aim to preserve the fidelity of the music, but they do so in different ways. Hi-res audio increases the amount of information captured in the recording, while lossless audio compresses the file size without losing any information. Depending on your preferences and equipment, you may prefer one over the other or both.

Is hi-res audio actually noticeable?

The jury may still be out on this question. Despite the seemingly humongous difference in terms of numbers between hi-res audio and CD-quality audio – or even non-hi-res formats (like AAC) – the benefits are a hotly-debated topic. However, when put up against low-quality MP3, the difference will be night and day. Ultimately, the difference comes down to the kind of audio format you’re upgrading from.

Just keep in mind that the term hi-res audio is used to refer to audio with support for frequencies that are beyond what the human ear is capable of hearing. Humans can hear sounds from about 20Hz to 20kHz. This is a key number when we apply the Nyquist-Shannon theorem, a mathematical formula that says you only need a sample rate that is twice the highest audio frequency you want to capture. Based on this, since humans can hear up to around 20kHz, we can theoretically notice the difference up to a sampling rate of 40kHz.

But hi-res audio goes much higher than that, reaching up to 384KHz. Some people may say they can tell the difference, but most people can’t – and that’s fine, because our ears are simply not designed to.

What do you need to experience true hi-res audio?

There’s a growing catalogue of music streaming services with support for hi-res audio, with the latest being Amazon Music. While audiophiles may have heard about Tidal, Deezer, and Qobuz, the reality is Amazon Music and Apple Music are the only services offering lossless/hi-res audio streaming in India. Spotify has also been saying it’s working on adding a new subscription tier with support for hi-res audio for years, but that’s yet to materialise.

Once you’ve got the right software, you then need to invest in the right hardware. The general thumb rule is that all wired earphones/headphones support lossless audio. Another essential component of a hi-res audio system is the playback device, such as your smartphone, laptop, or portable music player. Not all devices can handle hi-res audio files natively, so you may need to install a dedicated app or software that can decode and play them.

Of course, you also need a pair of speakers or headphones that can reproduce the high frequencies and wide dynamic range of hi-res audio. Keep in mind that the lack of even one of these bits will mean the sound output isn’t truly hi-res.

Is hi-res audio over Bluetooth possible?

It’s generally accepted that no version of Bluetooth can currently transmit hi-res lossless music. Certain Bluetooth codecs like Sony’s LDAC, Savitech’s LHDC, and Qualcomm’s aptX Adaptive supported by more premium headphones and earbuds are capable of transmitting slightly lossy hi-res music. But the catch is that you also need a smartphone/laptop/tablet/TV that supports the same format as your headphones for the two to work together.

Android phones costing above Rs 15,000 generally tend to support these formats, but Apple is a different story. Apple devices like the iPhone do support Apple Music’s version of lossless audio, but considering that Apple’s current audio lineup – which includes the flagship AirPods Max – only supports the lossy AAC codec, it’s impossible to listen to proper lossless on those. Apple devices also don’t support other codecs like LDAC, LHDC, or aptX.

Is it worth investing in hi-res audio?

Considering that it’s impossible for the average human to tell the difference between CD-quality and hi-res audio, the latter is a hard sell. The difference, if indeed discernible, is mostly only noticeable in a studio environment with little to no noise around. Therefore, if you are someone who likes to listen to music on the go, the hubbub around is enough to drown out any noticeable difference. Going through the pains of achieving true hi-res audio as described above may thus not be worth the hassle or the money.

If you can’t really hear the difference, it might be more important to focus on other aspects, such as whether your audio and your devices support technologies like Dolby Atmos or Spatial Audio for a more immersive experience. Ultimately, things aren’t always about specs, but simply about what sounds good to you, regardless of the sample rate, the bitrate, and any of that jargon.