How do I check sound card's bit resolution and sampling rate on Linux?

Question

I have a E-MU Tracker Pre USB sound card that supports playback at up to 24-bit resolution and 192 kHz sampling rate. It works on Linux and plays both 16bit/44.1kHz and higher-bitrate content; both from files and streaming.

However, I heard that this card only works as 16bit/44.1kHz on Linux. How do I check the actual bit resolution and sampling rate the sound card uses? Supposedly by starting playback and entering some command line commands to read the actual values.

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Using these instructions from a forum I was able to check the sample rate by doing

cat /proc/asound/card2/pcm0p/sub0/hw_params

I had to poke around and figure that card2 instead of card0 seems to be a working card on my system, but how do I know it's a E-MU Tracker Pre USB and not some other card, e.g. a built-in codec?

Answer 1

This might depend on which distro you use, so you might need to tweak these commands somewhat.

If you look in /proc/asound and do a ls -alh in this directory, you should see a list of cards named card0, card1 and so on, a few symlinks pointing to the cardn directories, and also a file called cards.

If you cat cards, you'll get something similar to mine below:

 0 [PCH            ]: HDA-Intel - HDA Intel PCH
                  HDA Intel PCH at 0xa3230000 irq 128
 1 [MOXF6MOXF8     ]: USB-Audio - Yamaha MOXF6/MOXF8
                  Yamaha Corporation Yamaha MOXF6/MOXF8 at usb-0000:00:14.0-4.4.1, full speed
 2 [UR22mkII       ]: USB-Audio - Steinberg UR22mkII
                  Yamaha Corporation Steinberg UR22mkII at usb-0000:00:14.0-6.1, high speed
 3 [NVidia         ]: HDA-Intel - HDA NVidia
                  HDA NVidia at 0xa3080000 irq 17

The ID you see at the beginning matches the number in the various card-directories. You can verify this by going into a cardn-directory and cat'ing the file id, which should give you the same name.