Hi, I have a Behringer X32 mixer. The default X-USB interface works great, it
appears as a S32_LE multichannel and has no problems up to 32 channels I/O. Im
using RaspberryPi4 as the host.
Generally I will be using mpd to play background and interval music from disk
or streaming.
I installed the newer X-live board in the X32 that has two SD slots for
recording and playback, plus it has (according to the blurb) “the same USB
interface as the X-USB board”. However when I play back audio, it has glitches
and pops. If I play a 1 minute duration wav file of 50Hz tone, it runs fine
for about 40 sec, then glitch.
The X-Live card supports S24_3LE only. As far as I can tell thats the only
difference.
I tested it thoroughly with a MacBook Pro running Catalina, and I dont get any
glitches, so the board and cable are good. Only with Alsa driving it do I seem
to get this problem. I tested 44.1 and 48, with the same result.
I tested with the default kernel 4.19 from raspbian, plus the version 5.4
below, same result. I tested both hw:1,0 and plughw:1,0, same result.
$ uname -a
Linux raspberrypi 5.4.49-v7l+ #1323 SMP Fri Jun 26 14:40:18 BST 2020 armv7l
GNU/Linux
pi@moode-pa:~ $ cat /proc/asound/card*/stream0
BEHRINGER X-LIVE at usb-0000:01:00.0-1.4, high speed : USB Audio
Playback:
Status: Stop
Interface 1
Altset 1
Format: S24_3LE
Channels: 16
Endpoint: 1 OUT (ASYNC)
Rates: 48000
Data packet interval: 125 us
Capture:
Status: Stop
Interface 2
Altset 1
Format: S24_3LE
Channels: 16
Endpoint: 1 IN (ASYNC)
Rates: 48000
Data packet interval: 125 us
pi@moode-pa:~ $
alsacap
Card 1, ID `XLIVE', name `X-LIVE'
Device 0, ID `USB Audio', name `USB Audio', 1 subdevices (1 available)
16 channels, sampling rate 48000..48000 Hz
Sample formats: S24_3LE
Buffer size range from 12 to 21845
Period size range from 6 to 10922
Subdevice 0, name `subdevice #0'
lsusb
Bus 001 Device 004: ID 1397:050a BEHRINGER International GmbH
pi@moode-pa:~ $ cat /proc/asound/XLIVE/usbmixer
USB Mixer: usb_id=0x1397050a, ctrlif=0, ctlerr=0
Card: BEHRINGER X-LIVE at usb-0000:01:00.0-1.4, high speed
USB Mixer: usb_id=0x1397050a, ctrlif=0, ctlerr=0
Card: BEHRINGER X-LIVE at usb-0000:01:00.0-1.4, high speed
Unit: 41
Control: name="X-LIVE Internal Clock Validity", index=0
Info: id=41, control=2, cmask=0x0, channels=1, type="BOOLEAN"
Volume: min=0, max=1, dBmin=0, dBmax=0
pi@moode-pa:~ $ cat /proc/asound/card1/pcm0p/sub0/hw_params
access: RW_INTERLEAVED
format: S24_3LE
subformat: STD
channels: 16
rate: 48000 (48000/1)
period_size: 5461
buffer_size: 21845
pi@moode-pa:~ $ cat /proc/asound/card1/pcm0p/sub0/sw_params
tstamp_mode: NONE
period_step: 1
avail_min: 5461
start_threshold: 16384
stop_threshold: 21845
silence_threshold: 0
silence_size: 0
boundary: 1431633920
pi@moode-pa:~ $ cat /proc/asound/card*/stream0
BEHRINGER X-LIVE at usb-0000:01:00.0-1.4, high speed : USB Audio
Playback:
Status: Running
Interface = 1
Altset = 1
Packet Size = 336
Momentary freq = 48000 Hz (0x6.0000)
Interface 1
Altset 1
Format: S24_3LE
Channels: 16
Endpoint: 1 OUT (ASYNC)
Rates: 48000
Data packet interval: 125 us
Capture:
Status: Stop
Interface 2
Altset 1
Format: S24_3LE
Channels: 16
Endpoint: 1 IN (ASYNC)
Rates: 48000
Data packet interval: 125 us
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