[skumrat]

I convert my 16/44.1 FLAC collection to Opus for mobile use which is natively 48kHz. I assume this is good enough to avoid any unnecessary resampling if both Android and the Bluetooth audio system detect 48kHz (Q5K seems to default to 48kHz as well), even without using UAPP? I know apps without that bit-perfect USB mode (and of course direct 3.5mm output on the phone itself) are subject to some sort of Android DSP effect that colours the sound, but is this still true of a Bluetooth pipeline where sampling rates are all 48kHz?

 

[monsieurfromag3]

Thank you for your clear explanation!

From what you say, I cannot do anything. Better leave everything at default for my use, then? I am listening to Amazon Music all day long using my 2 sets of FiiO UTWS5. Anything I can do there or leave everything at default?

Sometimes, I am using my Qudelix 5K to listen to Amazon again. Nothing I can do there, either, correct? So, even though I can set the Bluetooth audio sample rate at 44.1 kHz both on phone and in Qudelix app, Android bypasses that and upsamples everything to 48 kHz and then? Downsampled again to 44.1 in Qudelix? Or? Because that's what's showing in the Qudelix app, 44.1 is showing...

I am referring to Bluetooth only.

Right now I'm listening to Qobuz via UAPP with my Mojo 2 and everything is bit-perfect. No problem there but I will never use my Mojo 2 with my phone.

PS: I really really wish Qobuz wouldn't be so tragic when it comes to interface, music discovery and suggestions!

The data that rules everything is the original file’s sample rate. That’s what you’re trying to preserve. Amazon samples their catalog at 48kHz, which means Android won’t try and mess it up. So as you say, there’s nothing to do on your part.
On the contrary, you’d want to make sure neither your phone nor the 5K are resampling to 44.1. Same for the UTWS5, you can check the Dev Options on your phone to make sure the sample rate stays at 48 or 96.

Are you saying the Qudelix states a 44.1 sample rate without you selecting it? That would be weird. It would mean either the phone’s BT emitter chip spontaneously does 44.1 and you would need to manually select 48 in the Dev Options, or you have disabled 48 in the Qudelix menu and need to re-enable it.

Yeah Qobuz is fine but, as a Frenchman myself, their Frenchness annoys me
Plus their catalog has swathes of content missing for my taste, but they truly are the best for jazz and classical.

I convert my 16/44.1 FLAC collection to Opus for mobile use which is natively 48kHz. I assume this is good enough to avoid any unnecessary resampling if both Android and the Bluetooth audio system detect 48kHz (Q5K seems to default to 48kHz as well), even without using UAPP? I know apps without that bit-perfect USB mode (and of course direct 3.5mm output on the phone itself) are subject to some sort of Android DSP effect that colours the sound, but is this still true of a Bluetooth pipeline where sampling rates are all 48kHz?

You’re fine with Opus’ native 48kHz files then, Android won’t attempt its approximation of an upsampling. You’re basically preempting it, which is smart and what Amazon HD seem to be doing. Since LDAC defaults to 96, a multiple of 48, and aptX variants are stuck on 48, you are avoiding resampling along the chain.

The exception being AAC transmission which is locked at 44.1, so on Android you risk getting your files upsampled by Android then downsampled by the codec.

 

[Nick24JJ]

The data that rules everything is the original file’s sample rate. That’s what you’re trying to preserve. Amazon samples their catalog at 48kHz, which means Android won’t try and mess it up. So as you say, there’s nothing to do on your part.
On the contrary, you’d want to make sure neither your phone nor the 5K are resampling to 44.1. Same for the UTWS5, you can check the Dev Options on your phone to make sure the sample rate stays at 48 or 96.

Are you saying the Qudelix states a 44.1 sample rate without you selecting it? That would be weird. It would mean either the phone’s BT emitter chip spontaneously does 44.1 and you would need to manually select 48 in the Dev Options, or you have disabled 48 in the Qudelix menu and need to re-enable it.

Yeah Qobuz is fine but, as a Frenchman myself, their Frenchness annoys me
Plus their catalog has swathes of content missing for my taste, but they truly are the best for jazz and classical.

Thanks again for your response!

If Amazon samples their catalog at 48kHz why then does it say 44.1kHz in the app? Right now I'm listening to HD and it says Track quality 16 bit / 44.1 kHz. Next song, Ultra HD song, it says: Track quality 24 bit / 44.1 kHz. One more song Ultra HD, it says: track quality 24 bit / 192 kHz

Also, from here:
Amazon Music offers lossless audio in two quality ranges: HD and Ultra HD.
HD tracks have a bit depth of 16-bits, a minimum sample rate of 44.1 kHz (also referred to as CD-quality), and an average bitrate of 850 kbps. Ultra HD tracks have a bit depth of 24 bits, sample rates ranging from 44.1 kHz up to 192 kHz, and an average bitrate of 3730 kbps.


Re: Qudelix, no it stays to 44.1 only if I will select it exclusively in the App. Otherwise, when everything left at default, it plays at 96 kHz all the time, on my phone.

 

[monsieurfromag3]

Thanks again for your response!

If Amazon samples their catalog at 48kHz why then does it say 44.1kHz in the app? Right now I'm listening to HD and it says Track quality 16 bit / 44.1 kHz. Next song, Ultra HD song, it says: Track quality 24 bit / 44.1 kHz. One more song Ultra HD, it says: track quality 24 bit / 192 kHz

Also, from here:
Amazon Music offers lossless audio in two quality ranges: HD and Ultra HD.
HD tracks have a bit depth of 16-bits, a minimum sample rate of 44.1 kHz (also referred to as CD-quality), and an average bitrate of 850 kbps. Ultra HD tracks have a bit depth of 24 bits, sample rates ranging from 44.1 kHz up to 192 kHz, and an average bitrate of 3730 kbps.


Re: Qudelix, no it stays to 44.1 only if I will select it exclusively in the App. Otherwise, when everything left at default, it plays at 96 kHz all the time, on my phone.

Damn they’re devious I didn’t know that about Amazon Music, I thought the entire catalog was based on a 48kHz multiplier. Anyway since Amazon doesn’t let UAPP access their stream all you can do on an Android phone is eat the resampling to 48 on those 44.1 files. And from there let the codecs do their thing at 48 or 96kHz. So that 96 Qudelix reading is fine!

 

[rlw6534]

Damn they’re devious I didn’t know that about Amazon Music, I thought the entire catalog was based on a 48kHz multiplier. Anyway since Amazon doesn’t let UAPP access their stream all you can do on an Android phone is eat the resampling to 48 on those 44.1 files. And from there let the codecs do their thing at 48 or 96kHz. So that 96 Qudelix reading is fine!

On my DAPs and DACs, Amazon music always plays at 192 kHz, regardless of source quality. I assume that the app is resampling internally.

 

[Nick24JJ]

I just had a quick chat with Amazon Customer service. The Amazon Music app does not do any upsampling or downsampling of anything. The Amazon Music app plays the song at the exact sample rate and bit rate that it is transcoded in their music catalogue. If the device used is capable of playing in that sample rate, the song will play. Otherwise, the respective OS and its audio engine takes charge.

 

[Nick24JJ]

Damn they’re devious I didn’t know that about Amazon Music, I thought the entire catalog was based on a 48kHz multiplier. Anyway since Amazon doesn’t let UAPP access their stream all you can do on an Android phone is eat the resampling to 48 on those 44.1 files. And from there let the codecs do their thing at 48 or 96kHz. So that 96 Qudelix reading is fine!

LOL, hahah, eat it, how? Like a pancake? Nah, no need. Right now I'm listening to YouTube , because all the DJ mixes are there, and my Qudelix is fixed at 44.1 kHz, as per the suggestion in the app, and it sounds fantastic with LDAC fixed at 909 kbps! For the rest, I have UAPP. As for Amazon Music, we will see...

 

[rlw6534]

I just had a quick chat with Amazon Customer service. The Amazon Music app does not do any upsampling or downsampling of anything. The Amazon Music app plays the song at the exact sample rate and bit rate that it is transcoded in their music catalogue. If the device used is capable of playing in that sample rate, the song will play. Otherwise, the respective OS and its audio engine takes charge.

As I said above, the Amazon Music app (on Android) always plays at 192kHz on capable hardware, even for lower bitrate tracks. This is easily confirmed by bitrate displays and by looking at logcat. For bluetooth, it is resampled as needed depending on the codec in use. I doubt that Amazon customer service really knows what's happening at the hardware level. iOS may be a different story with the internal 48 kHz limitation, so YMMV.

 

[Nick24JJ]

A I said above, the Amazon Music app (on Android) always plays at 192kHz on capable hardware, even for lower bitrate tracks. This is easily confirmed by bitrate displays and by looking at logcat. For bluetooth, it is resampled as needed depending on the codec in use. I doubt that Amazon customer service really knows what's happening at the hardware level. iOS may be a different story with the internal 48 kHz limitation, so YMMV.

As I have clearly stated from my first post, on this matter, I own an Android phone and I am using my Qudelix via Bluetooth, exclusively, using LDAC. I have never referred to using the Qudelix connected with a cable, I have never referred to iPhones, either. My question was: on my Android phone, I have the option to select a sample rate of 44.1 kHz. When using the Amazon Music app, playing a song that it is 44.1, is this bit-perfect? And, what is happening when the song is 96 kHz? Those were my questions. The answers that I got, so far, tell me that Android resamples everything, unless using UAPP or a similar app. So, from what I understand so far, it is OS that resamples the audio signal, not the Amazon Music app.

 

[rlw6534]

As I have clearly stated from my first post, on this matter, I own an Android phone and I am using my Qudelix via Bluetooth, exclusively, using LDAC. I have never referred to using the Qudelix connected with a cable, I have never referred to iPhones, either. My question was: on my Android phone, I have the option to select a sample rate of 44.1 kHz. When using the Amazon Music app, playing a song that it is 44.1, is this bit-perfect? And, what is happening when the song is 96 kHz? Those were my questions. The answers that I got, so far, tell me that Android resamples everything, unless using UAPP or a similar app. So, from what I understand so far, it is OS that resamples the audio signal, not the Amazon Music app.

I probably didn't explain well, so I'll try again

It's not true that Android resamples everything to 48 kHz with recent phones and versions of android. It depends on the phone (or DAP). 192 kHz support is fairly widespread, especially since Android 9. Your device claims support for 24/192 (POCO F2 Pro).

The Amazon music app detects the maximum supported sample rate of your device (up to 192 kHz) and plays everything at that sample rate, even if the source rate is lower. So upsampling is taking place, either at Amazon's servers or in the Amazon app itself (I don't know which). When using BT, it's likely the same stream is sent to the BT driver/hardware where it is processed according to the codec.

So to summarize, if you are playing a 44.1 kHz track, it is upsampled to 24/192 and then sent to BT where it is resampled to your LDAC settings (44.1, 48, 88.2 or 96).

It is not bitperfect on Amazon even if you configure LDAC to 44.1.

To be clear, this issue is specific to the Amazon Music app. Most other apps (Apple, Qobuz, etc) play at the actual bitrate (if supported by the device).

You can get very near bitperfect if the track is 44.1 and LDAC is set to 44.1 (just not with Amazon's resampling).

This is what I believe is happening, but I've been wrong before...

 

[Nick24JJ]

I probably didn't explain well, so I'll try again

It's not true that Android resamples everything to 48 kHz with recent phones and versions of android. It depends on the phone (or DAP). 192 kHz support is fairly widespread, especially since Android 9. Your device claims support for 24/192 (POCO F2 Pro).

The Amazon music app detects the maximum supported sample rate of your device (up to 192 kHz) and plays everything at that sample rate, even if the source rate is lower. So upsampling is taking place, either at Amazon's servers or in the Amazon app itself (I don't know which). When using BT, it's likely the same stream is sent to the BT driver/hardware where it is processed according to the codec.

So to summarize, if you are playing a 44.1 kHz track, it is upsampled to 24/192 and then sent to BT where it is resampled to your LDAC settings (44.1, 48, 88.2 or 96).

It is not bitperfect on Amazon even if you configure LDAC to 44.1.

To be clear, this issue is specific to the Amazon Music app. Most other apps (Apple, Qobuz, etc) play at the actual bitrate (if supported by the device).

You can get very near bitperfect if the track is 44.1 and LDAC is set to 44.1 (just not with Amazon's resampling).

This is what I believe is happening, but I've been wrong before...

Thanks for your effort, explaining.

On my phone, things do not happen exactly like that. I would like to clarify for one more time that I am referring to the Bluetooth connection. I am connecting my Qudelix via Bluetooth with my phone. I never use a cable to connect it.

So, after disabling the Developer options and resetting all setting in the App, so after bringing everything back to the defaults, the Qudelix App is reporting:

Sample rate 96 kHz, Bits per sample 24 bit, bit rate 990 kbps, no matter what I play!

I've tested with the Amazon Music app, the Qobuz app, UAPP + Qobuz, even with the Music system app of my phone. Independently from the sample rate, mostly 44.1 kHz and the rest, in the Qudelix app it always shows the above.

This is shown under Input/State and also in the Volume menus

Which brings me to the most important question! What are these settings showing?! Are they showing what is set or are they showing the actual sample rate and bit depth of the song currently playing?

PS: of course, I've shut down the device and powered it on again and closed and reopened the app, as well

 

[DBaldock9]

Thanks for your effort, explaining.

On my phone, things do not happen exactly like that. I would like to clarify for one more time that I am referring to the Bluetooth connection. I am connecting my Qudelix via Bluetooth with my phone. I never use a cable to connect it.

So, after disabling the Developer options and resetting all setting in the App, so after bringing everything back to the defaults, the Qudelix App is reporting:

Sample rate 96 kHz, Bits per sample 24 bit, bit rate 990 kbps, no matter what I play!

I've tested with the Amazon Music app, the Qobuz app, UAPP + Qobuz, even with the Music system app of my phone. Independently from the sample rate, mostly 44.1 kHz and the rest, in the Qudelix app it always shows the above.

This is shown under Input/State and also in the Volume menus

Which brings me to the most important question! What are these settings showing?! Are they showing what is set or are they showing the actual sample rate and bit depth of the song currently playing?

PS: of course, I've shut down the device and powered it on again and closed and reopened the app, as well

Sounds like it's just reporting the LDAC codec properties - and not the properties of the original audio source (file or stream).

 

[Nick24JJ]

Sounds like it's just reporting the LDAC codec properties - and not the properties of the original audio source (file or stream).

Right, that's what I'm tending to conclude, as well. Is this what is really happening, though? Is this what you are observing, as well, with your phone and the app?
I would understand to show the set properties of the LDAC under Input/State but I would expect to show the actual properties of the currently playing stream and/or file in the Volume menu.

 

[monsieurfromag3]

Right, that's what I'm tending to conclude, as well. Is this what is really happening, though? Is this what you are observing, as well, with your phone and the app?
I would understand to show the set properties of the LDAC under Input/State but I would expect to show the actual properties of the currently playing stream and/or file in the Volume menu.

Well the Qudelix can only show what it’s receiving, which is a 96kHz LDAC stream from your phone. It’s got no access to anything beyond that. Only plugged in via USB can it show the properties of the stream it is reading - which, again, will only be what the phone is sending it, so with UAPP it will vary according to the original file but otherwise it will stay stuck at 48kHz.

 

[rlw6534]

Well the Qudelix can only show what it’s receiving, which is a 96kHz LDAC stream from your phone. It’s got no access to anything beyond that. Only plugged in via USB can it show the properties of the stream it is reading - which, again, will only be what the phone is sending it, so with UAPP it will vary according to the original file but otherwise it will stay stuck at 48kHz.

Totally agree except for the 48 kHz limitation, which is true for some devices (especially older ones) but not all, not anymore. Recent versions of android have support for 24/192 built-in, if the hardware is there.

Reference:

https://source.android.com/devices/audio/highres-effects