Article: Apple Music's Lossless and Hi-Res Mess

[Urbanluthier]

Hello Audiophile Style community, this is my very first post.

 

Like many, I was excited by the promise of lossless and high res streaming from the Apple Music service. However I found that, subjectively, I prefer the playback of my digital downloads and cd rips from Roon rather than Apple Music. I came across this thread looking for some sort of proof of wether the Apple Music App plays back bit perfectly when a mac or iOS device is connected directly to a DAC via USB. I confess I have not read this entire thread, so I apologize in advance if this is duplicate content. To my knowledge however, I don't think anyone else has published a test like this.

 

I own an RME ADI DAC 2 FS. RME provides series of bit test files (16, 24 and 32 bit files for 44.1, 48, 96 and 192 sample rates). The RME flashes Passed if the test file is received as bit perfect and these tests pass perfectly from Audirvana and ROON on my MacBook Pro. So presumably, playing these files through an Apple Music app (MacOS or iOS) we will know for sure whether the App itself is passing bit perfect data

 

I converted the RME WAV test files to ALAC and ran a few of tests. NB sound check and DSP were turned off in MacOS and iOS for these tests. Results of the first couple of tests are similar to what was reported in the first post. But the last test was a bit of a surprise. 

 

First test was to play the test files from the Apple Music App on my Macbook Pro. All test files passed except for the 16/48 file. (32bit files flash Passed as 24bit which is the same result as running the test through Audirvana or ROON). Since the Music App does not perform automatic sample rate switching, one must switch the sample rate with the Midi app and restart Apple Music for each sample rate test!!

 

For the second test I copied the test files to my iPad Air and ran the same test from Onkyo’s HF player app and the results were the same. All tests passed except for the 16/48 file. As we know, iOS does sample rate switching. Yea!

 

Sounds promising? Here’s where things get dicy.

 

For the last test, I turned off the Apple Music sync function and copied the RME test files over to my iPad Air and played them directly through the Apple Music App on the iPad. Here are the results:

• 16/48 - Failed
• 24/48 - Returned “Bit Test 16 Bit passed”
• 32/48 - Returned “Bit Test 16/24 Bit passed” flashed between 16/24
• 16/96 - Failed
• 24/96 - Returned “Bit Test 16 Bit passed”
• 32/96 - Returned “Bit Test 16/24 Bit passed” flashed between 16/24
• 16/192 - Failed
• 24/192 - Returned “Bit Test 16 Bit passed”
• 32/192 - Returned “Bit Test 16/24 Bit passed” flashed between 16/24
• 16/44 - Failed
• 16/24 - Returned “Bit Test 16 Bit passed”
• 16/32 - Returned “Bit Test 16/24 Bit passed” flashed between 16/24

All the 16 bit tests failed including the most important one 16/44! It also appears the 24 bit files are truncated to 16 bits. I'm a bit surprised considering everything passed through the Onkyo HF player on my iPad

 

I compared the playback of digital downloads I’ve purchased or ripped through Roon (server / ethernet connection) with the same files streamed trough the Apple Music service (iPad USB). Apple music sounds very good, but subjectively, I feel playback through Roon sounds better.

 

All subjectivity aside, I (like many here) simply want to know if Apple is passing bit perfect data via USB through their Apple Music App.

[Urbanluthier]

Update 

The logical response is that there must be something wrong with the test setup. I’m scratching my head wondering why. There must be a logical reason…

I repeated the test by copying over the original WAV test files from RME. I don’t believe there is a way to get info on a music file copied to an iDevice to verify it transferred correctly. The odd thing is that HF player will play non-DMR music copied to an iDevice. Every test file passes when played through HR player into the RME with the WAV files. These WAVs returned the same results as the original test when played through Apple Music app on iOS. Same files, different iOS apps used for playback with different results. Very strange

[Urbanluthier]

I cant seem to edit or modify my post above but I moved this conversation to the RME forum. If your are interested you can follow the conversation there. 

https://forum.rme-audio.de/viewtopic.php?pid=186724#p186724