1 (edited by urbanluthier 2022-04-18 15:19:13)

Topic: Apple Music iOS. RME Bit Tests fail

Hello RME user group, this is my very first post.

I've been using an ADI-2 in my desktop system for over a year - it is a fine product. Thank you!

Like many, I was excited to learn about the introduction of Apple Music's high-res and lossless streaming. So I though tI'd see if the RME bit test files pass when played through Apple Music app on MacOS 12.3.1 and iOS 15.4.1.  I can't believe I'm the only one who has thought of this, so feel free to let me know if this has been covered before. I posted this in a couple of other forums but haven't received much feedback.

Here are the results:

On MacOS, the RME WAV test files all pass - as long as correct sample rate is switched in the Apple MIDI app before the test files are played with the Music App. Music must be restarted after each sample rate switch however.

The results are quite different on iOS. I turned off the Apple Music sync function and copied the RME WAV test files over to my iPhone (one has to turn off the sync music function in the MacOS Music app to copy personal files over. I verified the files are the exact same size in the Storage app in iOS. High res streaming was turned On and all DSP functions and sound check were turned off for this test. the RME as connected to my iPhone by USB via an Apple CCK.

I first played the files through the handy Onkyo HF player and all the 16 and 24 bit tests passed! (The 32bit files pass as 24 bit as expected). Good start!

I then played the same files through the Music App on iOS and 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

So I'm left scratching my head... The Onkyo HF player on iOS reads, plays and passes all the RME tests. The iOS Music app fails to pass all the 16 bit tests, while the 24 bit tests passed as 16 bit! Same files. Very different results.

Thoughts?

2 (edited by KaiS 2022-04-17 21:32:12)

Re: Apple Music iOS. RME Bit Tests fail

Did you expect anything else from Apple?

As always, it‘s foolproof - means it behaves as foolish as possible.
What average Apple user cares about correct samplerate, bitdepth or anything.


Tidal on iOS works here, automatically switches sample rate etc.
No MQA of course.
Does it matter?
Most “HiRes” content is newly “remastered” stuff, means loudness pushed over the top until audible clipping unbearably spoils the sound anyway.
The original CDs release versions usually sound much better.

Sounding bitter?
That’s the “HiRes” reality that takes over more and more the last two years.

I’ve revoked my CD-player just lately, connected it to ADI-2 ‘s optical input.

Re: Apple Music iOS. RME Bit Tests fail

Thank you @kaiS.

Am I surprised? A little! My main reason for posting was to do a sanity check with the RME community to see if I did something wrong during my test that would affect the results. (I repeated it several times so i don't thing so!) Why on earth would Apple wast money and bandwidth to deliver high sample content that is essentially stripped to 16 bits? Even more confusing is that the most important sample rate test through the iOS music app - 16/44, Fails!

I certainly agree with you regarding loudness and many modern pop releases. I generally listen to newly recorded classical music, most of which is available in high res and is generally well recorded (often with RME AD converters!). Although I've seen more than a few classical releases of late that are upsampled and pushed too far from a loudness perspective.

Subjectively I feel that music (of whatever sample rate or bit depth) from Audirvana and ROON played directly into my RME via USB sounds better than Streaming the (supposedly) equivalent through the Music app via iOS and I wondered if this was purely a psychoacoustic response on my part. I'm starting to wonder...

4

Re: Apple Music iOS. RME Bit Tests fail

When 16/44 fails then you can expect volume control is in the path and unequal 0 dB. That might be the original volume setting (you might want to recheck), or a level change within the app (no way to circumvent that).

Regards
Matthias Carstens
RME

5 (edited by KaiS 2022-04-18 10:32:27)

Re: Apple Music iOS. RME Bit Tests fail

On iOS iDevice’s internal volume control is disabled when playing from the Apple/iOS Music app through CCK / USB to ADI-2.

The only setting affecting the output is activating Music app’s EQ in iPhone settings.

6 (edited by urbanluthier 2022-04-18 14:01:38)

Re: Apple Music iOS. RME Bit Tests fail

KaiS wrote:

On iOS iDevice’s internal volume control is disabled when playing from the Apple/iOS Music app through CCK / USB to ADI-2.

The only setting affecting the output is activating Music app’s EQ in iPhone settings.

Yes exactly - volume control is fixed when an iOS device is connected to the RME. When EQ is turned on, the iOS music app returns the following results: all 48KHz and 41.1KHz tests fail. 24/96 and 24/194 pass as 16 bit and 32/96 and 32/192 pass as flashing 16/24 bit.

Re: Apple Music iOS. RME Bit Tests fail

The most logical question now is whether the results described in post #1 can be reproduced...

8 (edited by KaiS 2022-04-18 15:29:40)

Re: Apple Music iOS. RME Bit Tests fail

urbanluthier wrote:

The most logical question now is whether the results described in post #1 can be reproduced...

Would be much easier for others if RME would put the files into streaming services.

Getting music files into the iDevices music app takes quite some effort.

I always wondered why such simple things need to be so complicated inside iDevices.
File handling and file-interoperability is still a pain in the ...

No way to download them on-device and put them where you want to.
Therefore the request above.

Re: Apple Music iOS. RME Bit Tests fail

KaiS wrote:
urbanluthier wrote:

The most logical question now is whether the results described in post #1 can be reproduced...

Would be much easier for others if RME would put the files into streaming services.

Getting music files into the iDevices music app takes quite some effort.
Therefore the request above.

Agree. It is a real pain to copy music from a Mac to an iDevice, but it is possible:

Step 1 - Import the RME WAV test files into Apple's Music app your Mac. (ensure there is no downsampling setting)
Step 2 - Turn off  "Sync Library" in the Music App settings on your iDevice
Step 3 - Connect your iDevice to your Mac and select "Sync Settings". Under the "Music" tab, chose the album to copy and click "sync"

10 (edited by Johannes AU 2022-04-18 18:58:51)

Re: Apple Music iOS. RME Bit Tests fail

From the Mac, Airdrop the bit test files to your iDevice(s) "Files", open the "Files" App, browse the folder you saved the bit test files, press play at each WAV files.

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

11 (edited by urbanluthier 2022-04-18 19:48:38)

Re: Apple Music iOS. RME Bit Tests fail

Johannes AU wrote:

From the Mac, Airdrop the bit test files to your iDevice(s) "Files", open the "Files" App, browse the folder you saved the bit test files, press play at each WAV files.

AirDrop works great for moving general files to an iPhone. It doesn't appear the Music app on iOS will read and play music files stored in a file folder on an iDevice copied via AirDrop.

I did copy the RME test files over from my Mac to my iPhone via AirDrop and saved them into a folder called I called Music. One can play these files directly by clicking on them, but playback appears to be through the iOS layer NOT the iOS Music app. The results are as follows:

- All 16 bit tests for each sample rate pass
- 24 bit test for each sample rate return passed 16/24 flashing (so likely a fail)
- Same for all 32.

12 (edited by Johannes AU 2022-04-18 20:18:15)

Re: Apple Music iOS. RME Bit Tests fail

urbanluthier wrote:
Johannes AU wrote:

From the Mac, Airdrop the bit test files to your iDevice(s) "Files", open the "Files" App, browse the folder you saved the bit test files, press play at each WAV files.

AirDrop works great for moving general files to an iPhone. It doesn't appear the Music app on iOS will read and play music files stored in a file folder on an iDevice copied via AirDrop.

I did copy the RME test files over from my Mac to my iPhone via AirDrop and saved them into a folder called I called Music. One can play these files directly by clicking on them, but playback appears to be through the iOS layer NOT the iOS Music app. The results are as follows:

- All 16 bit tests for each sample rate pass
- 24 bit test for each sample rate return passed 16/24 flashing (so likely a fail)
- Same for all 32.

At the MacOS Music app, the WAV import only up to 16/48. Whether the higher sample rate WAV file will be downsampled, I cannot confirm if send to the Music app will be different.

When I stream and shuffle songs or albums from Apple Music, it does automatically switches sampling rate, highest 192, which Apple supports and likely the highest rate at their library.

I understand your concern if the Apple Music app at iDevice can pass bit test or not, as you said, the bit test play at the iOS layer, I guess it is the same at the Music app because last June, I did contacted Apple to discuss this after the Apple Lossless service started, they said the lightning output support much higher than 24/192, you need the CCK and DAC to decode it, but commercial music they have is from 16/44 up to 24/96, rare recordings will up to 24/192.

There is an album, produced in Hongkong, the first song is 24/192, the rest are 24/96. This is one example that I checked if the sampling rate switches automatically and it does. I play same songs at MAC using either USB or Optical and compare with iPhone USB/CCK, I cannot find any difference in sound quality.

It is all I can share with you smile

P.S. Regarding the iOS layer, iPod Touch even support FLAC. if I have some files from my friend(s) which is higher than 16/48, I will keep it at the "Files" folder and play it direct from there, or convert to Apple Lossless (which is always a myth to us), which I prefer not to do in this way..... BTW, I only use streaming service of Apple Music. Sometimes I still play my old collection of CDs.

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

13 (edited by urbanluthier 2022-04-18 21:08:03)

Re: Apple Music iOS. RME Bit Tests fail

Johannes AU wrote:

At the MacOS Music app, the WAV import only up to 16/48. Whether the higher sample rate WAV file will be downsampled, I cannot confirm if send to the Music app will be different.

All the RME test files pass when played through the Music app on Mac OS as long as you switch the sample rate manually with the Midi app for each frequency.

As you note the Music app on iOS automatically switches sample rates with programme material played from the Apple Music Cloud service as long as high res is enabled. This works flawlessly with every DAC I have tried both from an iPhone with the CCK or from an iPad via USB C! I'm a classical music lover, so virtually every new release is high res.

What is in question here is to test whether the iOS Music app is truly playing back high res material at the correct bit depth and frequency. The results in post 1 suggest that iOS Music app is NOT playing back high res music bit perfectly, while Onkyo HF player is.

The only way we will get better clarity is if RME decides to upload their test files to the Apple Music cloud service as @KaiS suggested.

I'm doing my best not to rant here but it is an absolute nightmare to combine ones own music collection with the Apple Music service on an iOS device. Why do I care? often I don't want to listen to modern compressed remixes of older music and some labels like Hyperion Music do not have their catalogue on Apple Music.

14 (edited by Johannes AU 2022-04-19 06:35:23)

Re: Apple Music iOS. RME Bit Tests fail

urbanluthier wrote:
Johannes AU wrote:

At the MacOS Music app, the WAV import only up to 16/48. Whether the higher sample rate WAV file will be downsampled, I cannot confirm if send to the Music app will be different.

All the RME test files pass when played through the Music app on Mac OS as long as you switch the sample rate manually with the Midi app for each frequency.

As you note the Music app on iOS automatically switches sample rates with programme material played from the Apple Music Cloud service as long as high res is enabled. This works flawlessly with every DAC I have tried both from an iPhone with the CCK or from an iPad via USB C! I'm a classical music lover, so virtually every new release is high res.

What is in question here is to test whether the iOS Music app is truly playing back high res material at the correct bit depth and frequency. The results in post 1 suggest that iOS Music app is NOT playing back high res music bit perfectly, while Onkyo HF player is.

The only way we will get better clarity is if RME decides to upload their test files to the Apple Music cloud service as @KaiS suggested.

I'm doing my best not to rant here but it is an absolute nightmare to combine ones own music collection with the Apple Music service on an iOS device. Why do I care? often I don't want to listen to modern compressed remixes of older music and some labels like Hyperion Music do not have their catalogue on Apple Music.


I know what you mean, as I said, Apple Music is a myth to most of the Apple users. RME did their best to explain it at the manual, if RME can make it better, sure they will, let's wait and see, be this is not the problem of RME or any other dac manufacturer but APPLE, nothing we can change at the moment.... wish Apple will overhaul the Music app of iOS .....

A lot of Apple users rant, and I did it too, a long story to tell, may be one day I will quit Apple Music too, may be someone will file a court case questioning Apple altering the music contents which damaged the intellectual property....

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

Re: Apple Music iOS. RME Bit Tests fail

MC, when I run the bit test files at iOS layer, the bit test screen at the Dac shows pass and switching between 16 and 24 bit in the yellow box, is it a pass or fail?

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

Re: Apple Music iOS. RME Bit Tests fail

Johannes AU wrote:

... this is not the problem of RME or any other dac manufacturer but APPLE, nothing we can change at the moment.... wish Apple will overhaul the Music app of iOS .....

Yes I agree with you, the this certainly not RME's fault. We are lucky that RME gives us the tools to help verify bit perfect transfer!

Re: Apple Music iOS. RME Bit Tests fail

Johannes AU wrote:

MC, when I run the bit test files at iOS layer, the bit test screen at the Dac shows pass and switching between 16 and 24 bit in the yellow box, is it a pass or fail?

@Johannes - these are the results i get when I play the files back directly through the iOS layer (not the iOS music app)
- All 16 bit tests for each sample rate pass
- 24 and 32 bit test for each sample rate return passed 16/24 flashing (so likely a fail?)

18

Re: Apple Music iOS. RME Bit Tests fail

No steady display means fail. Note that for proper display you need to insert a pause of 0.5 s between different files, otherwise the refresh of the display will not happen and shows a wrong result that is not from the current file. Some players are so quick in changing from one file to the next that the display has no time to change its content.

Regards
Matthias Carstens
RME

Re: Apple Music iOS. RME Bit Tests fail

Thanks MC for the detail smile

That is so strange that iOS layer makes it switching at bit rate but correct in sampling rate within the 4s file ....

Pacifist, dumb, not stupid
Listen music out from a box which sounds
Reading words on paper/ screen

Re: Apple Music iOS. RME Bit Tests fail

MC wrote:

No steady display means fail. Note that for proper display you need to insert a pause of 0.5 s between different files, otherwise the refresh of the display will not happen and shows a wrong result that is not from the current file. Some players are so quick in changing from one file to the next that the display has no time to change its content.

Thanks for confirming @MC! Since the files are so short, I played each track on repeat, then stoped and moved to the next track.

Quick Question - what would cause a player to display a 16 bit pass for a 24 bit file? This is what happens with all the 24bit tests when played with iOS Music app.

21

Re: Apple Music iOS. RME Bit Tests fail

The test is very strict. Even a half-bit dither on the least significant bit (24) woud make it fail. And it doesn't check 23 bits. The next valid step it knows is 16 bits.

Regards
Matthias Carstens
RME

22 (edited by sberry2018 2022-05-01 08:53:21)

Re: Apple Music iOS. RME Bit Tests fail

Apple Music itself does some dithering or watermarking.

Watch this:

https://www.youtube.com/watch?v=fGLbXsf5gZE

This explains why Apple Music app fails or behaves strange (flicking between 16b and 24 bit - i had same issue).

And explains why Onkyo app passes 16b and 24b properly from same iOS device - I can reproduce this

So it's not an iOS problem. iOS is definitely capable. it is Apple Music app "quirk". Probably deliberate design thing by Apple.

Did you get Onkyo app on iOS to pass 32bit test? Only shows 24 bits on my ADI-2. Not a problem in practical sense though. I'm happy with 16bit passing.


urbanluthier wrote:

Thank you @kaiS.

Am I surprised? A little! My main reason for posting was to do a sanity check with the RME community to see if I did something wrong during my test that would affect the results. (I repeated it several times so i don't thing so!) Why on earth would Apple wast money and bandwidth to deliver high sample content that is essentially stripped to 16 bits? Even more confusing is that the most important sample rate test through the iOS music app - 16/44, Fails!

I certainly agree with you regarding loudness and many modern pop releases. I generally listen to newly recorded classical music, most of which is available in high res and is generally well recorded (often with RME AD converters!). Although I've seen more than a few classical releases of late that are upsampled and pushed too far from a loudness perspective.

Subjectively I feel that music (of whatever sample rate or bit depth) from Audirvana and ROON played directly into my RME via USB sounds better than Streaming the (supposedly) equivalent through the Music app via iOS and I wondered if this was purely a psychoacoustic response on my part. I'm starting to wonder...

Johannes AU wrote:

From the Mac, Airdrop the bit test files to your iDevice(s) "Files", open the "Files" App, browse the folder you saved the bit test files, press play at each WAV files.

23 (edited by urbanluthier 2022-05-01 15:00:58)

Re: Apple Music iOS. RME Bit Tests fail

Thanks for the confirmation that Apple is indeed doing something during playback in the iOS Music app that prevents bit perfect playback. Nice to know I'm not crazy!

Yes Onkyo HF player on iOS passes all the files 16 and 24 bit files. Only the 32 bit fail (they flash 24/32)

24 (edited by Curt962 2022-05-02 15:08:58)

Re: Apple Music iOS. RME Bit Tests fail

Urban,

Herein lies the Real Value of the RME Bit Test Utility.   It is simply intolerant of ANY manipulation of the Digital Data in the Path between your source file, and the DAC.   RME users at large, purchase RME to be assured of the most un-fettered reproduction of their Digital Material, and Bit Test is your Best, First Line of Defense to ensure this is possible.   We've seen more than one Player Sftwr, and Device fall short.  Bit-Test simply looks at the data, and without regard to however "fashionable" a device/sftwr may be...Passes Judgement accordingly.

You're not Crazy!

Thanks for running Bit Test, and seeing for yourself.

*Late edit:  I would encourage You, or others to add Bit-Test to your Tool-Kit.   I like this, and routinely use Bit-Test to validate my work after any upstream component FW update, etc just to be sure I haven't corrupted anything.   I LIKE Bit Test!

Best,

Curt

Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes

25 (edited by txbdan 2022-07-30 19:45:34)

Re: Apple Music iOS. RME Bit Tests fail

FWIW, using the RME test files and the Music app on my Mac. All sample rates pass at 16bit and 24bit, but the 32bit files show passing as 24bit. Is that what you see, urbanluthier?

I also found you have to restart Music whenever you change the sample rate. That's pretty annoying, actually. MacOS/Music needs to get with the program on automatic sample rate selection.

Also, I confirmed that SoundSource passes the test if, of course, the volume is at 100% and no plugins are used. I use this to host my Dirac Live processor. Of course Dirac moots all of this, but its nice to know that SoundSource on its own can pass things through properly.

26 (edited by Curt962 2022-07-30 20:02:48)

Re: Apple Music iOS. RME Bit Tests fail

txbdan wrote:

FWIW, using the RME test files and the Music app on my Mac. All sample rates pass at 16bit and 24bit, but the 32bit files show passing as 24bit. Is that what you see, urbanluthier?


Tx, how are you connected?  Bear in mind that Coax/Opt connections are SPDIF, and only 24bit is supported.

Else?  A tiny amount of dither could cause the 32 bit test to act up.

In reality?  At 32bit?  It won't matter, and you won't hear the slightest difference.

I understand our need to see the selected test to PASS as such (my Rpi passes 32bit all day) but there reaches a point...

Tell us more!  There may be a logical solution. 

*The Apple thing gives me pause...

Best,

Curt

Vintage 2018 ADI-2 DAC. "Classic AKM4490 Edition"
Cables:  Red, and White Ones.
Speakers:  Yes

Re: Apple Music iOS. RME Bit Tests fail

Curt962 wrote:
txbdan wrote:

FWIW, using the RME test files and the Music app on my Mac. All sample rates pass at 16bit and 24bit, but the 32bit files show passing as 24bit. Is that what you see, urbanluthier?


Tx, how are you connected?  Bear in mind that Coax/Opt connections are SPDIF, and only 24bit is supported.

Else?  A tiny amount of dither could cause the 32 bit test to act up.

In reality?  At 32bit?  It won't matter, and you won't hear the slightest difference.

I understand our need to see the selected test to PASS as such (my Rpi passes 32bit all day) but there reaches a point...

Tell us more!  There may be a logical solution. 

*The Apple thing gives me pause...

Best,

Curt

Using USB via a thunderbolt docking station connected to my M1 MacBook Air.

Yeh, I'm not too concerned about it, but thought I'd check for consistency.

Re: Apple Music iOS. RME Bit Tests fail

Apple audio stack is 32bit float but dac/pro uses 32bit int. so 24 bits is expected to pass. 32bits are not possible unless you dont use the core audio stack. some software supports integer mode via HAL can do 32bit perfectly. generally it's not useful as dac chip does not preserve > 20bit linearity anyway.

Re: Apple Music iOS. RME Bit Tests fail

Apple Music doesn't even like 24bit files and 48KHz is their SP top.  I use Foobar for higher SR playback on the phone and/or Qobuz for hi-resolution streaming.

If I load music to Apple Music from my library I always limit the SR to 48KHz and dither any 24bit files to 16.

_______________________
Eric Seaberg • San Diego, CA
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