Still no bit-perfect passthrough capability with Apple Music lossless audio on macOS??
I'm super happy that Apple Music finally supports lossless audio, but the lack of a 'bit-perfect' digital passthrough option is a critical gap that prevents me - and likely most folks who care enough about audio quality to bother with high-resolution lossless audio via external DAC - from adopting it as my primary source of audio enjoyment. I hope I just haven't found the setting for this or it's coming soon??
The problem
Since the bitrate for lossless music could be any of (all in kHz): 44.1, 48, 88.2, 96, 176.4, 192 but the digital audio output format remains fixed, one must click on the lossless logo to check which format is being used, then go into the separate Audio MIDI Setup app and set the matching output format - for *every* song/album that I play on Apple Music. This is the only way to ensure that the digital audio signal isn't modified by your Mac before being passed to your DAC! Not exactly a great user experience ...
There are third party apps for purchase that will do this for you (ensure the output format matches the audio file being played to ensure the signal is passed through unadulterated), but this shouldn't be necessary!
Supporting high-resolution lossless audio but not providing an option to ensure the digital output matches what was downloaded without modification is a huge miss by Apple and I truly can't understand why they would do this!
Please follow my logic:
- It has been known for a while that higher bitrate/bitdepth audio - if recorded and engineered properly - has the capability to sound noticeably better than music encoded at the traditional RedBook CD standard of 44.1kHz/16-bits when played back on appropriately capable equipment.
- Apple is a high-end luxury brand and has recognized that there is strong enough demand for high-resolution audio amongst it's customer base - or else why both offering high-resolution audio above 48kHz at all?
- Use of these higher bitrates requires an external DAC to decode the digital audio and convert it to an analog signal before sending it to your amplifier -> speakers/headphones. This is a good thing, because general purpose computers are not designed for best audio performance and tend to be extremely noisy and hostile environments for analog signals, undoing any benefit of high-resolution audio. However, digital signals don't suffer from such problems and can be passed through perfectly bit-for-bit ...
- The goal of high-end audio is generally to faithfully reproduce the original audio performance as much as possible, which requires significant care at every step in the chain. Illustrative example: the utopian amplifier is idealistically referred to as a 'strait wire with gain' - meaning it can amplify the signal without adding/subtracting anything or coloring the sound at all.
- If you care enough about audio quality such that you've gone through the trouble and expense of enabling high-resolution audio and have setup an external DAC, the last thing in the world you want is for your general purpose computer (or anything!) to modify the audio signal from input to output - and rest assured that re-clocking the bitrate is an audible modification in most cases!
- Audio producers and Apple have made the non-trivial investment in high-resolution audio - requiring more expensive recording and mastering equipment as well as significantly more storage - with the only benefit being better sound quality. The only way to use those high resolution lossless files (above 48kHz) is to pass the digital audio to an external decoder, yet no option is provided to ensure that the downloaded file is passed through to the output without being modified, which is antithetical to the goal of accurate high end audio reproduction!
- Bit-perfect passthrough of digital audio isn't complicated, it already can be done either manually by changing the audio output format in Audio MIDI setup to match the format of each song or via third-party software.
Therefore - unless I'm just an idiot and haven't found the setting or it's 'coming soon' - I can only conclude that Apple doesn't really care about high-resolution audio or their customers who seek to enjoy it, and are only in it for the marketing - now they can say they support lossless!
Unfortunately this means that as much as I truly want to, I still won't be using Apple Music - and I doubt most of the folks who were asking for high-resolution lossless audio will be yet either. Lack of this feature really undermines the investment already made in lossless audio and is such a simple thing to do that I can't possibly understand why it hasn't been done yet!?
I truly believe that this is incredibly low hanging fruit for Apple at this point - it would likely be trivial to implement, and is the only thing holding many people back from subscribing to Apple Music and making it their primary audio source!
MacBook Pro 15″, macOS 10.13