Hi-res audio Airplay2 options...

DudeDah

macrumors newbie
Original poster
Dec 3, 2003
20
0
Hello...if this has been discussed please send me to that thread but...I am wanting to stream some of my hi-res audio I have in my iTunes library to a set of KEF LS50 wireless speakers. I was going to use an older ATV with Toslink but it seems the software within the ATV downsamples the audio. Is there a hack that removes or replaces the software that downsamples the audio or what other options are available to stream hi-res audio from iTunes to a device that I can then connect to the LS50?

THX!!
 

Marco Klobas

macrumors regular
Jul 14, 2017
146
243
Italy
Airplay (the first version) is limited to 44.1 kHz. For the 2nd version I haven't found any official technical specs. Some say it's capable of 96kHz. I'm still looking for confirmation.

AppleTV unfortunately upsample everything to 48 kHz.

For example, if you play a 192 kHz track this is what happens -> Airplay downsamples it to 44.1 kHz and send it to AppleTV -> AppleTV upsamples it to 48kHz. Your KEFs will get a 48 kHz signal. Definitely not bit perfect.

The sound it's not terrible. The purists/audiophiles are still annoyed by this down-upsampling nonsense, though.

If your DAC/Speakers accept USB digital audio and if you have an iPad/iPhone you can connect it via a lightning-USB adapter. The tracks played from a locally shared iTunes library are sent in the native resolution. In my case I have to put a powered USB hub between the iPad and the DAC to make it work otherwise I get a power related alert.

It works: not wireless of course and a little cable-messy. I don't know if this model works in the same way.
 

DudeDah

macrumors newbie
Original poster
Dec 3, 2003
20
0
Airplay (the first version) is limited to 44.1 kHz. For the 2nd version I haven't found any official technical specs. Some say it's capable of 96kHz. I'm still looking for confirmation.

AppleTV unfortunately upsample everything to 48 kHz.

For example, if you play a 192 kHz track this is what happens -> Airplay downsamples it to 44.1 kHz and send it to AppleTV -> AppleTV upsamples it to 48kHz. Your KEFs will get a 48 kHz signal. Definitely not bit perfect.

The sound it's not terrible. The purists/audiophiles are still annoyed by this down-upsampling nonsense, though.

If your DAC/Speakers accept USB digital audio and if you have an iPad/iPhone you can connect it via a lightning-USB adapter. The tracks played from a locally shared iTunes library are sent in the native resolution. In my case I have to put a powered USB hub between the iPad and the DAC to make it work otherwise I get a power related alert.

It works: not wireless of course and a little cable-messy. I don't know if this model works in the same way.
Thanks for your reply, yeah I have been doing a bunch of research trying to figure this out. I have one Gen2 ATV and two Gen3 ATVs just laying around that I thought I might use because of the TOSLINK output. Now I am thinking to use one of the GEN2 Airport Express' I have as well since the signal won't be processed twice. The plan is hook the AX into my network via Ethernet and then the 3.5mm Mini TOSLINK to the KEFs. Wanted to go this route so that I could easily toggle to those speakers in iTunes on my work machine. That was my ideal scenario.

BUT...now I am thinking about using my old Mac Pro (2008) and going out through the Digital out on that machine directly into the digital input on the KEFs. That should pass through the hi-res audio signal its just that I will have to control that machine via screen sharing or the Remote app...just not as smooth a "workflow".

BUT...☺...I may be replacing that Mac Pro with a new Mini in which case I'd get a USB-C to USB-B adaptor and plug into the KEFs that way with a similar "workflow" to the Mac Pro route.

Thanks for playing along
 

Marco Klobas

macrumors regular
Jul 14, 2017
146
243
Italy
The Airport Express is surely more "hi-fi" because, as you say, there's less processing (only downsampling to 44.1 kHz due to Airplay's limit).

The wired MacPro/mini way is even more "audiophile" (actually it's perfect from an audio point of view). I've a Mac mini connected to a DAC through USB. Using iTunes with an app like BitPerfect you even don't have to switch manually the sample rate in Audio MIDI Setup in order to match the sample rate of the songs. Everything is done automatically and the Remote app let you remotely control the playback as you pointed out.

BitPerfect unfortunately crashes from time to time. It's related to the last versions of iTunes. Previous versions of iTunes worked fine. Developers are struggling to figure out a solution. There are other hi-res-iTunes companion apps available, though.

I, like many other "picky audio guys", understand what are you trying to accomplish. Managing your audio library natively with iTunes and enjoying hi-res audio at the same time.

I like Apple in many ways: I wish they would be more audio friendly in this sense. AppleTV should simply have an option to enable bitperfect playback. At least it'd act like an Airport Express. I know, 48 kHz is the standard in the video field – still, it sounds to me a silly decision to force upsampling.

I own an AppleTV 4 which doesn't have the TOSLINK output. I have to use an audio HDMI-TOSLINK de-embedder to hook it to my DAC. Just another example of Apple complicating audio users' lives. ;)
 
Last edited:

DudeDah

macrumors newbie
Original poster
Dec 3, 2003
20
0
The Airport Express is surely more "hi-fi" because, as you say, there's less processing (only downsampling to 44.1 kHZ due to Airplay's limit).

The wired MacPro/mini way is even more "audiophile" (actually it's perfect from an audio point of view). I've a Mac mini connected to a DAC through USB. Using iTunes with an app like BitPerfect you even don't have to switch manually the sample rate in Audio MIDI Setup in order to match the sample rate of the songs. Everything is done automatically and the Remote app let you remotely control the playback as you pointed out.

BitPerfect unfortunately crashes from time to time. It's related to the last versions of iTunes. Previous versions of iTunes worked fine. Developers are struggling to figure out a solution. There are other hi-res-iTunes companion apps available, though.

I, like many other "picky audio guys", understand what are you trying to accomplish. Managing your audio library natively with iTunes and enjoying hi-res audio at the same time.

I like Apple in many ways: I wish they would be more audio friendly in this sense. AppleTV should simply have an option to enable bitperfect playback. At least it'd act like an Airport Express. I know, 48 kHZ is the standard in the video field – still, it sounds to me a silly decision to force upsampling.

I own an AppleTV 4 which doesn't have the TOSLINK output. I have to use an audio HDMI-TOSLINK de-embedder to hook it to my DAC. Just another example of Apple complicating audio users' lives. ;)
I have heard of BitPerfect and JUST started to look into it. It's great that it automatically "senses" the sample rate of the audio. Does the MIDI setup default BACK if the speakers receive audio of a lower sample rate? I would think if you assigned settings to the output in MIDI setup they should remain. But...I don't know, just diving in and I APPRECIATE your input. I'm also looking into Audirvana as well but, again, just starting to look into it.

Yeah it's a bummer that Apple is not doing more to accommodate hi-res audio at this point ESPECIALLY for the ATV since it is the only native Apple option left for this type of "workflow" (adding airplay functionality to non airplay equipped speakers/receivers/DACs). It would also be great if KEF would add support for Airplay with the LS50 wireless. They offer airplay 2 support for their LSX model. Then I am assuming you could plug the KEFs into your network via ethernet and they would appear as an airplay option in iTunes. Is Airplay 2 functionality integrated via hardware or software? The LS50 wireless have a streamer built in (for Tidal, Roon, Spotify IIRC) but it doesn't have airplay 2 functionality.
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The Airport Express is surely more "hi-fi" because, as you say, there's less processing (only downsampling to 44.1 kHZ due to Airplay's limit).
Oh and...I thought I'd read...whether it's true or not I don't know...that the ATV's processing of the audio was done in the software so I was hoping that the software available to hack the Gen 2 ATV might remove the sampling but I haven't found that to be mentioned anywhere.
 

Marco Klobas

macrumors regular
Jul 14, 2017
146
243
Italy
I have heard of BitPerfect and JUST started to look into it. It's great that it automatically "senses" the sample rate of the audio. Does the MIDI setup default BACK if the speakers receive audio of a lower sample rate? I would think if you assigned settings to the output in MIDI setup they should remain. But...I don't know, just diving in and I APPRECIATE your input. I'm also looking into Audirvana as well but, again, just starting to look into it..
Yes, as soon as you stop the music (stop, not pause) the sample rate in MIDI setup revert back to the original settings.

Yeah it's a bummer that Apple is not doing more to accommodate hi-res audio at this point ESPECIALLY for the ATV since it is the only native Apple option left for this type of "workflow" (adding airplay functionality to non airplay equipped speakers/receivers/DACs). It would also be great if KEF would add support for Airplay with the LS50 wireless. They offer airplay 2 support for their LSX model. Then I am assuming you could plug the KEFs into your network via ethernet and they would appear as an airplay option in iTunes. Is Airplay 2 functionality integrated via hardware or software? The LS50 wireless have a streamer built in (for Tidal, Roon, Spotify IIRC) but it doesn't have airplay 2 functionality.
I don't know exactly how Airplay 2 is integrated. Some devices have been updated via firmware adding Airplay 2 compatibility. I assume it's mainly a software solution. After all there are compatible Airplay (first version) receivers based on Raspberry Pi devices.

Here's an official Apple list of Airplay 2 devices (available and upcoming). I find interesting the Bluesound NODE 2i receiver. The reviews of their companion app aren't great, though. Another device I'm curious about is a receiver by B&W which is coming soon.

I'm not aware of the existence of a hack for Gen 2 Apple TV to remove the upsampling.
 

albertfallickwa

macrumors 6502a
Jan 27, 2014
543
38
I am in the same position since I subscribe to the high-resolution of Tidal... For playback I am thinking about doing LDAC Bluetooth to a pair of future Triangle Elara speakers... not sure how that's going to work however.