Bad AEC performance. Tips?

[RafigRzayev]

Hello, I am using the mic for smart-speaker application.

Microphone is connected to a single board computer via USB. Sound system is connected to 3.5mm audio jack on the microphone for AEC to work. Below is the demonstration of setup:

I have watched your video showing the AEC performance, and it seems very good. I hoped that I will have similar results, but unfortunately microphone recording gets distorted by the signal emitted through speaker more than on your video. When I compared recording of single-channel firmware vs the first-channel of 6-channel firmware(processed for AEC), the quality of the latter is much better. But still it is not sufficient. I need to understand what is wrong with my setup, and why it doesn't work as in your video.

For my application I am using Linux, and this is what I do for audio settings:

pactl load-module module-remap-source master=alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input master_channel_map=front-left channel_map=front-left remix=false
pactl set-default-sink alsa_output.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.analog-stereo
pactl set-default-source alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input.remapped

Through this, I make sure that only the first channel is used for my voice detection application(clear of noise), and that audio output is streamed into the microphone for the filtering purpose.

• Below are various logs from pulse-audio regarding sampling rate and etc. Could you please check if it they are ok for good AEC performance?
• What can I do to improve the noise cancellation?
• May it be that amplifier induces a delay which worsens the filtering? If yes, what would you suggest?
• Which tuning parameters could help?

from pacmd stat:

Default sample spec: s16le 2ch 44100Hz
Default channel map: front-left,front-right
Default sink name: alsa_output.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.ag-stereo
Default source name: alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.ichannel-input.remapped

from pacmd list-sources:

• index: 5
  name: <alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input.remapped>
  driver: <module-remap-source.c>
  flags: DECIBEL_VOLUME LATENCY DYNAMIC_LATENCY
  state: RUNNING
  suspend cause: (none)
  priority: 1000
  volume: front-left: 65536 / 100% / 0.00 dB
  balance 0.00
  base volume: 65536 / 100% / 0.00 dB
  volume steps: 65537
  muted: no
  current latency: 1.03 ms
  max rewind: 0 KiB
  sample spec: s16le 1ch 16000Hz
  channel map: front-left
  used by: 2
  linked by: 2
  configured latency: 8.69 ms; range is 0.50 .. 2000.00 ms
  module: 25
  properties:
  device.master_device = "alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input"
  device.class = "filter"
  device.description = "Remapped ReSpeaker 4 Mic Array (UAC1.0) Multichannel"
  device.icon_name = "audio-input-microphone"

from pacmd list-sinks:

• index: 1
  name: <alsa_output.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.analog-stereo>
  driver: <module-alsa-card.c>
  flags: HARDWARE DECIBEL_VOLUME LATENCY DYNAMIC_LATENCY
  state: SUSPENDED
  suspend cause: IDLE
  priority: 9549
  volume: front-left: 55000 / 84% / -4.57 dB, front-right: 55000 / 84% / -4.57 dB
  balance 0.00
  base volume: 65536 / 100% / 0.00 dB
  volume steps: 65537
  muted: no
  current latency: 0.00 ms
  max request: 0 KiB
  max rewind: 0 KiB
  monitor source: 2
  sample spec: s24le 2ch 16000Hz
  channel map: front-left,front-right
  Stereo
  used by: 0
  linked by: 0
  configured latency: 0.00 ms; range is 0.50 .. 2000.00 ms
  card: 1 <alsa_card.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00>
  module: 8
  properties:
  alsa.resolution_bits = "24"
  device.api = "alsa"
  device.class = "sound"
  alsa.class = "generic"
  alsa.subclass = "generic-mix"
  alsa.name = "USB Audio"
  alsa.id = "USB Audio"
  alsa.subdevice = "0"
  alsa.subdevice_name = "subdevice #0"
  alsa.device = "0"
  alsa.card = "0"
  alsa.card_name = "ReSpeaker 4 Mic Array (UAC1.0)"
  alsa.long_card_name = "SEEED ReSpeaker 4 Mic Array (UAC1.0) at usb-fe3e0000.usb-1, full speed"
  alsa.driver_name = "snd_usb_audio"
  device.bus_path = "platform-fe3e0000.usb-usb-0:1:1.0"
  sysfs.path = "/devices/platform/fe3e0000.usb/usb4/4-1/4-1:1.0/sound/card0"
  udev.id = "usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00"
  device.bus = "usb"
  device.vendor.id = "2886"
  device.vendor.name = "SEEED"
  device.product.id = "0018"
  device.product.name = "ReSpeaker 4 Mic Array (UAC1.0)"
  device.serial = "SEEED_ReSpeaker_4_Mic_Array__UAC1.0_"
  device.form_factor = "speaker"
  device.string = "front:0"
  device.buffering.buffer_size = "192000"
  device.buffering.fragment_size = "96000"
  device.access_mode = "mmap+timer"
  device.profile.name = "analog-stereo"
  device.profile.description = "Analog Stereo"
  device.description = "ReSpeaker 4 Mic Array (UAC1.0) Analog Stereo"
  module-udev-detect.discovered = "1"
  device.icon_name = "audio-speakers-usb"
  ports:
  analog-output: Analog Output (priority 9900, latency offset 0 usec, available: unknown)
  properties:

   active port: <analog-output>
  

P.S. If you want I can make a video which shows performance on audacity.

[TomasWeij]

Hi, did you ever manage to improve this? I'm trying to create a proper speakerphone, but the loopback is insane.

[Shulyaka]

Try something like this with pulseaudio 17:

set-card-profile alsa_card.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00 output:analog-stereo+input:multichannel-input
update-sink-proplist alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input device.description="ReSpeaker Mic Array v2.0" device.form_factor='internal' device.product.name='Seeed Studio ReSpeaker Mic Array v2.0'

# Create `respeaker.raw` source for raw mic input
load-module module-remap-source source_name=respeaker.raw source_properties="device.description='ReSpeaker\ Mic\ Array\ v2.0\ Raw\ Data' device.form_factor='internal' device.product.name='Seeed\ Studio\ ReSpeaker\ Mic\ Array\ v2.0' device.intended_roles='test'" master=alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input master_channel_map=front-right,rear-left,front-center,rear-right channel_map=front-left,front-right,rear-left,rear-right remix=false

# Create `respeaker.voice` source for internal AEC
load-module module-remap-source source_name=respeaker.voice source_properties="device.description='ReSpeaker\ Mic\ Array\ v2.0\ Processed\ Audio\ for\ ASR' device.form_factor='internal' device.product.name='Seeed\ Studio\ ReSpeaker\ Mic\ Array\ v2.0' device.intended_roles='test'" master=alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input master_channel_map=front-left channel_map=mono remix=false

# Create `respeaker.echo-cancel` source and `respeaker` sink for PulseAudio AEC
load-module module-echo-cancel source_name=respeaker.echo-cancel source_properties="device.form_factor='internal' device.product.name='Seeed\ Studio\ ReSpeaker\ Mic\ Array\ v2.0'" source_master=respeaker.raw sink_name=respeaker sink_properties="device.icon_name='audio-speakers' device.form_factor='internal' device.product.name='Seeed\ Studio\ ReSpeaker\ Mic\ Array\ v2.0' device.intended_roles='video\ music\ phone\ animation'" sink_master=alsa_output.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.analog-stereo use_volume_sharing=true use_master_format=true aec_method=webrtc aec_args="digital_gain_control='1' analog_gain_control='0' noise_suppression='1' transient_noise_suppression='1'" save_aec=false

set-default-sink respeaker
set-default-source respeaker.echo-cancel

[TomasWeij]

Holy, this worked better than expected. Many thanks Denis. Op vr 23 mei 2025, 17:20 schreef Denis Shulyaka ***@***.***>:

…

*Shulyaka* left a comment (respeaker/usb_4_mic_array#70) <#70 (comment)> Try something like this with pulseaudio 17: set-card-profile alsa_card.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00 output:analog-stereo+input:multichannel-input update-sink-proplist alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input device.description="ReSpeaker Mic Array v2.0" device.form_factor='internal' device.product.name='Seeed Studio ReSpeaker Mic Array v2.0' # Create `respeaker.raw` source for raw mic input load-module module-remap-source source_name=respeaker.raw source_properties="device.description='ReSpeaker\ Mic\ Array\ v2.0\ Raw\ Data' device.form_factor='internal' device.product.name='Seeed\ Studio\ ReSpeaker\ Mic\ Array\ v2.0' device.intended_roles='test'" master=alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input master_channel_map=front-right,rear-left,front-center,rear-right channel_map=front-left,front-right,rear-left,rear-right remix=false # Create `respeaker.voice` source for internal AEC load-module module-remap-source source_name=respeaker.voice source_properties="device.description='ReSpeaker\ Mic\ Array\ v2.0\ Processed\ Audio\ for\ ASR' device.form_factor='internal' device.product.name='Seeed\ Studio\ ReSpeaker\ Mic\ Array\ v2.0' device.intended_roles='test'" master=alsa_input.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.multichannel-input master_channel_map=front-left channel_map=mono remix=false # Create `respeaker.echo-cancel` source and `respeaker` sink for PulseAudio AEC load-module module-echo-cancel source_name=respeaker.echo-cancel source_properties="device.form_factor='internal' device.product.name='Seeed\ Studio\ ReSpeaker\ Mic\ Array\ v2.0'" source_master=respeaker.raw sink_name=respeaker sink_properties="device.icon_name='audio-speakers' device.form_factor='internal' device.product.name='Seeed\ Studio\ ReSpeaker\ Mic\ Array\ v2.0' device.intended_roles='video\ music\ phone\ animation'" sink_master=alsa_output.usb-SEEED_ReSpeaker_4_Mic_Array__UAC1.0_-00.analog-stereo use_volume_sharing=true use_master_format=true aec_method=webrtc aec_args="digital_gain_control='1' analog_gain_control='0' noise_suppression='1' transient_noise_suppression='1'" save_aec=false set-default-sink respeaker set-default-source respeaker.echo-cancel — Reply to this email directly, view it on GitHub <#70 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHADIGIQHTHQAJZKNBSWEFL2744ETAVCNFSM6AAAAAB5Y4I45OVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSMBUG44TINZWGY> . You are receiving this because you commented.Message ID: ***@***.***>