Bad AEC performance. Tips? #70
Description
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.remappedThrough 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.