Historically, the relationship between the iPhone and hi-res music over the years has been a complicated one. It’s a shame, because we’ve always found iPhones to be among the best-sounding smartphones around.
Apple has never really pushed the notion of playing high-resolution audio on its smartphones and users have had to rely on workarounds to get their iPhones to play nicely with hi-res files.
However, times, they are a changin’. Thanks to the emergence of music streaming services armed with millions of hi-res tracks, it’s actually never been easier to get hi-res music onto your iPhone. In fact, Apple is positively encouraging it, thanks to the recent unveiling of its Apple Music Lossless and Hi-Res Lossless tiers, which are being added to its own music streaming service.
So the job of getting hi-res music on your iPhone has become easier but what about playing it? Being able to enjoy multiple flavours of hi-res audio is possible, but depending on the quality of your hi-res files, there can be a bit of extra work involved. Allow us to explain.
What music files can your iPhone play?
Let’s start with what the iPhone can do out of the box. According to Apple’s own specs, it can play MP3, AAC, ALAC, WAV and AIFF audio files. The iPhone also supports FLAC files, but only through Apple’s Files app. This was introduced as part of iOS11, which launched in 2017. There is no native support for DSD.
How do I transfer hi-res files to my iPhone?
Before the advent of hi-res music streaming services, hi-res files would normally be stored on a computer, and you’d need to employ a third-party app such as Vox or Onkyo HF player to play them back on your smartphone. This would involve dragging and dropping files from your Mac laptop or desktop to these apps on your iPhone.
However, the likes of Tidal, Amazon Music HD (and soon, Apple Music) all offer iOS apps, which allow you to either stream hi-res music through the iPhone directly or you can download and store hi-res files through these apps onto your iPhone. This means they’re available to listen to “offline” i.e. when you don’t have any wi-fi or mobile network access.
Can you listen to hi-res audio on an iPhone over Bluetooth?
The removal of the 3.5mm headphone jack has pushed people more towards wireless headphones such as the AirPods (2019) and AirPods Max. The only problem here is that you can’t transmit full-fat hi-res audio over Bluetooth.
Some formats such as AptxHD Bluetooth and LDAC allow for hi-res files to be streamed wirelessly between compatible devices but not without compression. The former supports audio at 24-bit/48kHz, but uses compression and has a maximum data rate of 576kbps. The latter supports up to 32-bit/96kHz over Bluetooth but only with a data rate of 990kbps. Both of these are lower than the data rate of CD (1411kbps) which isn’t technically hi-res...
So how can the iPhone play hi-res music?
If you want to play hi-res music you are limited by the DACs inside Apple’s devices.
To listen via a pair of wired headphones, you need to use Apple’s Lightning-to-3.5mm adapter which is limited to supporting 24-bit/48kHz.
Technically, 24-bit/48kHz can be classed as hi-res, but some tracks from the aforementioned streaming services will be 24-bit/96kHz or even 24-bit/192kHz. If you try and play these files through the same adapter, the iPhone will just downsample them to 24-bit/48kHz.
Similarly, you could go down the Lightning headphones route and plug a pair straight into your iPhone, but you’ll need to check what resolution their DAC can handle. We haven’t come across any that can handle above 24-bit/48kHz.
Really, if you want to listen to anything at 24-bit/96kHz or higher, you need to connect your iPhone to an external DAC.
What kit do you need to play hi-res on your iPhone?
First, you’ll need to invest in Apple’s Lightning-to-USB camera adapter (£29) which forms a link between your iPhone and the DAC.
This is just a starting point, of course. Don’t be afraid to build up to a more revealing system, though. You could combine the Chord Hugo 2 DAC with a pair of Beyerdynamic T1 (3rd Generation) headphones for a more premium set-up. That might be a touch overkill and punishingly transparent for an iPhone, but these are hi-res files, after all.
And remember a number of these DACs usually have ways of indicating what sample rate is being played, so you can make sure your headphones are being fed the best sound quality possible from your files.
Of course, we’ll be the first to admit that connecting external kit to your iPhone 12 isn’t the most elegant solution, but if you want to hear the full original resolution of your hi-res files through your iPhone above and beyond 24-bit/48kHz, using an external DAC with your iPhone is really the only way to go.
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- MP3, AAC, WAV, FLAC: all the audio file formats explained
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