Audio source distorted aes67 -> dante

[LydiaSevelt]

Hello, I'm getting extremely distorted audio from an aes67 source going to a dante network. I feel like I've tried every combination of options I can and it just won't work, I could always swear I've tested this and had it work in the past and my notes seem to indicate it should all be working.

I'm at 48 TIC frame size and 48k hz with L24

Here are my configs:
daemon.conf
{
"http_port": 8080,
"rtsp_port": 8854,
"http_base_dir": "/usr/local/share/aes67-daemon/webui/",
"log_severity": 1,
"playout_delay": 0,
"tic_frame_size_at_1fs": 48,
"max_tic_frame_size": 1024,
"sample_rate": 48000,
"rtp_mcast_base": "239.69.0.1",
"rtp_port": 5004,
"ptp_domain": 0,
"ptp_dscp": 48,
"sap_mcast_addr": "239.255.255.255",
"sap_interval": 30,
"syslog_proto": "",
"syslog_server": "255.255.255.254:1234",
"status_file": "/etc/status.json",
"interface_name": "enx34298f564a4b",
"mdns_enabled": true,
"custom_node_id": "OBS Input",
"node_id": "OBS Input",
"ptp_status_script": "/usr/local/share/aes67-daemon/scripts/ptp_status.sh",
"mac_addr": "34:29:8f:56:4a:4b",
"ip_addr": "192.168.###.###",
"streamer_channels": 8,
"streamer_files_num": 8,
"streamer_file_duration": 1,
"streamer_player_buffer_files_num": 1,
"streamer_enabled": false,
"auto_sinks_update": true
}

/etc/status.json
{
"sources": [
{
"id": 0,
"enabled": true,
"name": "Stream 1",
"io": "Audio Device",
"max_samples_per_packet": 48,
"codec": "L24",
"address": "239.69.0.5",
"ttl": 15,
"payload_type": 98,
"dscp": 34,
"refclk_ptp_traceable": false,
"map": [ 0, 1 ]
} ],
"sinks": [
{
"id": 0,
"name": "ALSA Sink 0",
"io": "Audio Device",
"use_sdp": true,
"source": "http://192.168.###.###:8080/api/source/sdp/0",
"sdp": "v=0\r\no=- 51173506448 51173506473 IN IP4 192.168.###.###\r\ns=SQ-5 : 128\r\nc=IN IP4 239.69.91.139/32\r\nt=0 0\r\na=keywds:Dante\r\nm=audio 5004 RTP/AVP 97\r\ni=2 channels: 21, 22\r\na=recvonly\r\na=rtpmap:97 L24/48000/2\r\na=ptime:1\r\na=ts-refclk:ptp=IEEE1588-2008:00-04-C4-FF-FE-06-3C-98:0\r\na=mediaclk:direct=1558512902\r\n",
"delay": 576,
"ignore_refclk_gmid": true,
"map": [ 0, 1 ]
} ]
}

It's an Ubuntu Studio install:

Linux OBS-Input 6.11.0-25-generic #25-Ubuntu SMP PREEMPT_DYNAMIC Fri Apr 11 23:29:18 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=off preempt=full threadirqs"

I've tried stopping wireplumber pipewire pipewire-pulse entirely and only communicating directly to the Revenna alsa device and it's the same results.

speaker-test -D plughw:RAVENNA -r 48000 -c 2 -t sine -F S24_3LE
This sounds like crunchy trash instead of a nice tone. (running another dante source through the same input chain comes out clean, it's this box for sure)

Let me know if you have any idea what I might be missing here.

[SimonTait]

On R.Pi3B+ I've found 3 main causes of crunchy/aliased/clipped audio going to & from Dante:

1. Interfacing with Dante networks required the pcm description in /etc/asound.conf to match the native endinan-ness of any Dante stream which is big-endian even. Otherwise I found wrongly-ordered bytes and sometimes even channel-swapping interference. For me, a working config was :: `pcm.play {
   type dmix
   ipc_key 221277
   slave {
   pcm "hw:RAVENNA,0"
   format S32_BE
   channels 4
   rate 48000
   buffer_size 2048
   }
   bindings {
   0 0
   1 1
   2 2
   3 3
   }
   }

pcm.capture {
type dsnoop
ipc_key 221277
slave {
pcm "hw:RAVENNA,0"
format S32_BE
rate 48000
channels 4
buffer_size 2048
}
bindings {
0 0
1 1
2 2
3 3
}

}
` And on my Pi I can simply play and record at whatever format I please and ALSA will do the format conversion.
2. Unless you have a NIC with hardware timestamping, playback will be jittery and unreliable at low latency & buffer values because the operating system needs to timestamp the packets, which makes it subject to fluctuating system load.
3. I modified my systemd service to start the AES67 daemon with nice -20 and realtime privelages. I don't know how much difference this made but it's a dedicated device so everything else can just wait in line 😊!

Also pay attention to the usual Dante clocking rules - NEVER set a 'Preferred Master' unless you're clocking from an external device like a GPS or BNC.