topic title: Audio Sampling Rate
Posts: 2
cocobowl
Joined: 08 Sep 2015
#1
Hi, I have reason to believe (but am not certain) my PCI sound card is sampling at 48kHz, rather than 96kHz it should be. I was wondering how to set the audio sampling rate in antiX 13. The exact sound card is Creative Labs SB0570 PCI Sound Blaster Audigy SE.

I have an antenna, an amplifier, and some software that turns VLF radio signals into a visual db vs frequency graph. The antenna plugs into the amplifier which plugs into the line in jack of the sound card. I have had this setup working for a few years but now all of a sudden it doesnt seem to be sampling at 96kHz anymore. I know this because I am seeing aliasing effects in the data consistent with the Nyquist theorem of sampling. It may have been students messing with it or some kind of hardware failure that caused the change, I really dont know.

I dont normally use linux so I am a bit lost on how to get the sample rate setting right again.
Posts: 4,164
rokytnji
Joined: 20 Feb 2009
#2
Not being a musician myself. That is einos department (he is a member here). All I can do is point you to


========= SCRAPER REMOVED AN EMBEDDED LINK HERE ===========
url was:"http://unix.stackexchange.com/questions/74558/change-sampling-rate-in-alsa"
linktext was:"http://unix.stackexchange.com/questions ... te-in-alsa"
====================================


Howdy and Welcome to AntiX.
Posts: 630
Eino
Joined: 12 Oct 2012
#3
Install the alsa-plugins package to enable upmixing/downmixing and other advanced features.

then add this to / etc/asound.conf

Code: Select all

pcm.dsp {
    type plug
    slave.pcm"dmix"
}
This will enable hardware mixing of your sound card.
The most problems come from, flash players messing up hardware's original configurations.
Posts: 2
cocobowl
Joined: 08 Sep 2015
#4
Hi, thanks for the replies. Before checking back here I tried editing /usr/share/alsa/alsa.conf and changed

defaults.pcm.dmix.rate 48000
to
defaults.pcm.dmix.rate 96000

which worked. The aliasing isnt visible anymore in my spectrum analysis.

I will have to research upmixing and downmixing to understand if thats something I want, but good to know there are options out there for hardware features.
Posts: 630
Eino
Joined: 12 Oct 2012
#5
cocobowl wrote: I will have to research upmixing and downmixing to understand if thats something I want, but good to know there are options out there for hardware features.
Please note, builtin sound cards, do not have upmixing and downmixing features. and your stuck with the highest rate of 48000 kHZ. The player software with a FLAC file may show a higher rate, but the output will still be 48000 kHZ.