Audio Test

The Rhino Pi IQ9N (Rhino Pi IQ9N) provides speaker output and microphone array input interfaces, and has an onboard audio processing module supporting acoustic echo cancellation (AEC) and beamforming noise reduction.

Hardware Specifications

Item	Parameter
Speaker	2 x 5W Speaker
Microphone	4Mic Array omnidirectional mic
Audio module capability	Supports 4/6 MIC, wake-up, beamforming noise reduction, echo cancellation, directional pickup, VOIP call noise reduction (switchable via commands)
Pickup distance	Supports 5m long-distance pickup; recording distance adjustable from 1 ~ 5m
AEC	Used with USB 2.0, supports AEC noise reduction and microphone array

Interface Definitions

For the positions of the SPK, AEC, and I2S interfaces on the board, see the interface layout diagram in Rhino Pi IQ9N Interface Description on the first page.

SPK Speaker Interface

There are 2 SPK interfaces in total, using WAFER-PH2.0-2PWB connectors (PH2.0, horizontal SMT, 2P):

Pin	Signal	Description
1	SPK_P	Speaker positive
2	SPK_M	Speaker negative

AEC Interface

The AEC interface uses a WAFER-GH1.25-4PLB connector (1.25mm pitch, vertical SMT, 4P):

Pin	Signal	Description
1	LINE_LP	Left channel positive
2	LINE_LM	Left channel negative
3	LINE_RP	Right channel positive
4	LINE_RM	Right channel negative

I2S Interface

The I2S interface uses a WAFER-GH1.25-4PLB connector:

Pin	Signal	Description
1	DATA	Audio data
2	SCK	Bit clock
3	WS	Frame clock (channel select)
4	GND	Ground

Viewing Audio Devices

Use the following commands to view the audio devices recognized by the system:

# ALSA-level device enumeration (the onboard sound card is card 0)
aplay -l
arecord -l

# Default input / output and volume at the PipeWire level
wpctl status

Audio on the IQ9N is managed uniformly by PipeWire. aplay -l / arecord -l list ALSA devices, while actual playback and recording go through the PipeWire default sink / source by default.

Playback Test

Use aplay to play a WAV audio file for testing (without -D it automatically uses the PipeWire default output):

aplay test.wav

# Or use the PipeWire playback tool
pw-play test.wav

Recording Test

Use arecord to record audio (without -D it automatically uses the PipeWire default input):

arecord -f S16_LE -c 1 -r 16000 -d 5 test.wav

# Or use the PipeWire recording tool (press Ctrl+C to stop)
pw-record --rate 16000 --channels 1 mic_test.wav

Here -d 5 means recording for 5 seconds and -c 1 means mono; the onboard microphone is mono, so -c 1 must be specified when recording.

Before recording, you can check the sample rates, formats, and channel counts supported by the default device:

arecord --dump-hw-params

Note

When using aplay / arecord, do not use -D hw:x,y to take exclusive control of the hardware, as this conflicts with PipeWire and reports Device or resource busy; without -D, the command automatically uses the PipeWire default input and output.

The commands above must be run in a terminal of the AidLux desktop (user aidlux); in the root environment of adb shell PipeWire is not reachable, and aplay / arecord will report Host is down.

For volume adjustment, input / output device switching, and more usage, see Audio Development.