Moode USB Output

[Tim Curtis]

There is no _deviceout.conf file in 7.3.0 and _audioout.conf is set via the ALSA output mode option in Audio Config. The "plughw" ALSA plugin performs automatic format conversion if needed. In other words if the format being sent by the player application is not valid for the audio device then ALSA will attempt to adjust the bit depth and sample rate to a format the device accepts. Thats how it is supposed to work.

Also note that the Spotify and Airplay renderers always output to "plughw" regardless of the ALSA output mode setting.

The alsacap output in your previous post shows that the audio device accepts 16 bit format at sample rates ranging from 8K to 48K.

I have no idea why the device only plays 48K and not 44.1K.

[pyhfsg]

There is no _deviceout.conf file in 7.3.0 and _audioout.conf is set via the ALSA output mode option in Audio Config. The "plughw" ALSA plugin performs automatic format conversion if needed. In other words if the format being sent by the player application is not valid for the audio device then ALSA will attempt to adjust the bit depth and sample rate to a format the device accepts. Thats how it is supposed to work.

Also note that the Spotify and Airplay renderers always output to "plughw" regardless of the ALSA output mode setting.

The alsacap output in your previous post shows that the audio device accepts 16 bit format at sample rates ranging from 8K to 48K.

I have no idea why the device only plays 48K and not 44.1K.

Thanks, what else would you suggest I try changing in the Airplay and Spotify renderer? I really want to make this work as I find Moode is a lot more stable and easier to configure compared to my first attempt with the other audio player.

[TheOldPresbyope]

@pyhfsg 

I'm just as puzzled as Tim about this.

I'm using a Creative Technology USB-BT transceiver to drive my Sennheiser BT headphones here in our hotel room (some people, even my SO, aren't all that fond of Mahler!).

The DAC accepts only 48kbps 48kHz-sampled material (alsacap reports 2 channels, sampling_rate 48000..48000 Hz). It works fine with MPD, Spotify, and Airplay renderers with ALSA Default plughw which, as Tim says, is the only option for the Spotify and Airplay renderers.

Here's a sample output from the Audio info command (it's a screen-scrape so formatting is a bit wonky)

Code:

Audio information
Input / Output
Source Airplay stream
Encoded at Unknown
Decoded to 16 bit, 44.1 kHz, Stereo, VBR
Output rate 16 bit, 48 kHz, Stereo, 1.536 Mbps
Output mode ALSA Default (plughw)
Output chain Airplay -> Crossfeed -> plughw -> Device
DSP operations
Resample rate
Selective rate
CamillaDSP Off
Volume mixer Software (MPD)
Audio Device
Device Creative Bluetooth Audio W2
Mixer name PCM

The only difference between my audio path and yours that I've noticed so far is that there is no hardware volume control available in my DAC so I'm using the software volume mixer.

Hint: when setting up moOde, it's best to accept all the default settings and then make only the minimum changes needed to select the DAC being used. This has always worked for me. Everything can be fine-tuned to suit individual taste later.

Regards,
Kent

[TheOldPresbyope]

@pyhfsg 

PS - when using the Spotify and Airplay renderers, volume is controlled from the remote app. You are turning the volume up in the app, right?

[pyhfsg]

@pyhfsg 

PS - when using the Spotify and Airplay renderers, volume is controlled from the remote app. You are turning the volume up in the app, right?

yes, I am using the Spotify app on my iphone to change the volume. I also notice the "initial volume" in the Moode Spotify renderer is working, i.e. when connected, the volume on the Spotify on my iphone correspond to the setting.

In the Spotify config, the lowest bit rate I can select is 96K, the default is 160K, is that normal? And is this a different attribute from the 48K you mentioned earlier?

Thanks

[pyhfsg]

@pyhfsg 

I'm just as puzzled as Tim about this.

I'm using a Creative Technology USB-BT transceiver to drive my Sennheiser BT headphones here in our hotel room (some people, even my SO, aren't all that fond of Mahler!).

The DAC accepts only 48kbps material (alsacap reports 2 channels, sampling_rate 48000..48000 Hz). It works fine with MPD, Spotify, and Airplay renderers with ALSA Default plughw which, as Tim says, is the only option for the Spotify and Airplay renderers.

Here's a sample output from the Audio info command (it's a screen-scrape so formatting is a bit wonky)

Code:

Audio information
Input / Output
Source Airplay stream
Encoded at Unknown
Decoded to 16 bit, 44.1 kHz, Stereo, VBR
Output rate 16 bit, 48 kHz, Stereo, 1.536 Mbps
Output mode ALSA Default (plughw)
Output chain Airplay -> Crossfeed -> plughw -> Device
DSP operations
Resample rate
Selective rate
CamillaDSP Off
Volume mixer Software (MPD)
Audio Device
Device Creative Bluetooth Audio W2
Mixer name PCM

The only difference between my audio path and yours that I've noticed so far is that there is no hardware volume control available in my DAC so I'm using the software volume mixer.

Hint: when setting up moOde, it's best to accept all the default settings and then make only the minimum changes needed to select the DAC being used. This has always worked for me. Everything can be fine-tuned to suit individual taste later.

Regards,
Kent

Thanks Kent. May be I should reinstall the Moode again as you suggested. In fact, i believe the only thing I changed was the sampling rate (16/48) in MPD options which got the audio working (for web radio only).

[TheOldPresbyope]

@pyhfsg 

PS - when using the Spotify and Airplay renderers, volume is controlled from the remote app. You are turning the volume up in the app, right?

yes, I am using the Spotify app on my iphone to change the volume. I also notice the "initial volume" in the Moode Spotify renderer is working, i.e. when connected, the volume on the Spotify on my iphone correspond to the setting.

In the Spotify config, the lowest bit rate I can select is 96K, the default is 160K, is that normal? And is this a different attribute from the 48K you mentioned earlier?

Thanks

My bad. I typed kbps (a bit-rate unit) where I meant kHz (a sampling-rate unit). I've gone back and corrected the original post.

I use the default 160K bit-rate setting for my Spotify renderer.

Regards,
Kent

[pyhfsg]

        Hi Kent, Tim,
 
Following Kent’s suggestion, I reinstalled Moode on my SD card and tired the following settings:
 
1.     All settings defaulted. No sound from web radio, Spotify. The only sound I get is when I played the test file.
2.     Changed the MPD settings to enable SoX Resampling with “any” Bit depth, “any” Sample rate and Selective resampling “Disabled”.  No sound for both web radio and Spotify.
3.     Same as #2, but changed SoX Resampling to 16 Bit depth, and Sample rate to 48. Web radio works but no sound from Spotify
4.     I then played with the “Selective resampling” with Bit depth set to 16 bit and Sample rate to 48KHz. The results are that I only get sound if the output rate is 16 bit, 48 KHz. I noticed some of the source is decoded to 24 bit and 44.1 KHz and output to 16 bit and 48 KHz. Please see the attached screen captures.
5. If I understand both of you correctly that Spotify only supports output rate of 44.1 KHz. Does that confirm my active speaker can only plays at 48KHz even though it supposed to play anything between 8000 and 48000Hz.

 
Please let me know if the above makes sense and if you have any other troubleshooting suggestions. Thanks.

[TheOldPresbyope]

@pyhfsg

Seems like maybe your speaker system is lying to Linux about its capabilities. I've never run across this and don't know how best to prove it [1]. I couldn't find any technical information worth spit about the PSB Alpha AM3 but after I read they claim "zero distortion" I didn't really expect useful technical information anyway.

One experiment which takes Spotify out of the equation is to transfer a 44.1 kHz track to the uSD card and see what setting changes you have to make to be able to play it through the speakers.

You can also try using Bluetooth out to the speaker. That, at least, would allow you to enjoy music while pondering

Regards,
Kent

[1] Also, I've been known to be wrong before.

[pyhfsg]

@pyhfsg

Seems like maybe your speaker system is lying to Linux about its capabilities. I've never run across this and don't know how best to prove it [1]. I couldn't find any technical information worth spit about the PSB Alpha AM3 but after I read they claim "zero distortion" I didn't really expect useful technical information anyway.

One experiment which takes Spotify out of the equation is to transfer a 44.1 kHz track to the uSD card and see what setting changes you have to make to be able to play it through the speakers.

You can also try using Bluetooth out to the speaker. That, at least, would allow you to enjoy music while pondering

Regards,
Kent

[1] Also, I've been known to be wrong before.

Thanks Kent. May be you are right, the speaker I have gave the wrong spec. Will give that a try later, although I am not very optimistic. This is my first attempt with RPi, I was excited I could go this far without major challenge until Spotify/Airplay. Wish i have another pair of USB speakers to test this.

What is the best way for me to transfer a 44.1KHz track to my SDCard?