INTERACT FORUM

Please login or register.

Login with username, password and session length
Advanced search  
Pages: [1]   Go Down

Author Topic: Sample Rate won't stay set  (Read 712 times)

johnjen

  • Galactic Citizen
  • ****
  • Posts: 321
  • Sonicus Caelumus Tremendamus
Sample Rate won't stay set
« on: September 18, 2019, 03:09:07 am »

So I go into the Output Format control in the DSP and set all the SR's to 88.2
I save this setup and exit the DSP.
I stop the player and restart and the SR reverts to 48 for all SR's, Except 44.1 and 48 which are listed as no change.

In fact I'm playing 44.1 music and the player up-samples it to 48 regardless of what I set the SR's to.
I have stopped the player, restarted MC, even restarted the mac and the player stays on 48 even though the SR window says no change for both 44.1 and 48 and all the other SR's are set to 48 after the tracks begin playing.

What am I missing?

Oh yeah on my Mac Pro setup it works just peachy keen, it's only happening on this MacBook Air.
Is there a corrupted preference file or setup parameter I can delete and have the app rebuild?

JJ
Logged
Custom 71A HP amp, Schiit Jggy dac, HD-800-Jmod, AOIP digital data feed, custom wiring and mains power feed, Mac Pro 4cpu 16GB ram SSD's

blgentry

  • Regular Member
  • Citizen of the Universe
  • *****
  • Posts: 8014
Re: Sample Rate won't stay set
« Reply #1 on: September 18, 2019, 03:14:56 pm »

What sound device (DAC or otherwise) are you using and how are you connecting the Mac to it? 

These symptoms are not familiar to me.  Just trying to get some more diagnostic information.

Brian.
Logged

johnjen

  • Galactic Citizen
  • ****
  • Posts: 321
  • Sonicus Caelumus Tremendamus
Re: Sample Rate won't stay set
« Reply #2 on: September 18, 2019, 06:45:25 pm »

The MacBook Air is connected via USB to Jolida Glass FX tube DAC directly.
And is the only external connection to the MB Air.

And I believe I have found why it limits the SR to 48K…

This early (2013) MB Air can only deal with up to 48K via the USB C-Media audio controller.

Bummer…

JJ
Logged
Custom 71A HP amp, Schiit Jggy dac, HD-800-Jmod, AOIP digital data feed, custom wiring and mains power feed, Mac Pro 4cpu 16GB ram SSD's

blgentry

  • Regular Member
  • Citizen of the Universe
  • *****
  • Posts: 8014
Re: Sample Rate won't stay set
« Reply #3 on: September 19, 2019, 10:33:46 am »

And I believe I have found why it limits the SR to 48K…

This early (2013) MB Air can only deal with up to 48K via the USB C-Media audio controller.

That's really weird.  If you have a reference I'd like to read it.  I say it's weird because 48kHz audio isn't a lot of data.  USB3 is way faster than even 192kHz audio.  You're saying it's due to a chipset limitation in the C-Media USB controller built in to the Macbook air?  That's a really odd limitation. But I've heard stranger things about computers before.  :)

Brian.
Logged

johnjen

  • Galactic Citizen
  • ****
  • Posts: 321
  • Sonicus Caelumus Tremendamus
Re: Sample Rate won't stay set
« Reply #4 on: September 19, 2019, 04:23:58 pm »

Yeah I was surprised when I stumbled across it as well.
There were 2 'indicators'…
#1 when I went into "Audio Midi Setup" it limited the USB connection to either 44.1 or 48KB
#2 I searched for the specs for this MB Air on the Apple site and it confirmed that the USB controller was limited to 88.2KB but the audio capability was limited to 48KB.

This was an unexpected limitation I wouldn't have even suspected, that there was a hardware limit.
And granted this MB Air is from 2013, even so…

Mystery solved.
Now I just have to deal with it.

JJ
Logged
Custom 71A HP amp, Schiit Jggy dac, HD-800-Jmod, AOIP digital data feed, custom wiring and mains power feed, Mac Pro 4cpu 16GB ram SSD's
Pages: [1]   Go Up