Wi-Fi Multi-Speaker

Supported SoCs

SoC

RTL8721Dx

RTL8720E

RTL8713E

RTL8726E

RTL8730E

Wi-Fi MultiSpeaker

Y

N

N

N

Y

Overview

Ameba Wi-Fi Audio is a solution developed for wireless audio applications. It operates in 5GHz portion of the Wi-Fi spectrum and is capable of transmitting 12 independent 48kHz PCM audio channels with ultra low latency and extremely low synchronization between speakers. The solution is ideal for home theater systems such as TV, Soundbar and wireless surrounds application. In includes following features:

  • High Quality Audio: Audio can be delivered with 48kHz/96kHz/192kHz sample rate. By adopting a lossless format, the solution achieves negligible THD+N levels, preserving original audio quality with near-perfect accuracy.

  • Ultra Low Latency: Ultra-low fixed latency ensures perfect audio-video synchronization. The latency meets the ITU-R BT1359-1 specification.

  • Inter-channel Synchronization: An extremely low delay between different wireless channels ensures a high quality audio experience.

  • Robust Wireless Transmission: A series of technology is employed to deliver strong interference resistance and robust performance.

../rst_solutions/figures/wifi_multispeaker_overview.svg

Description

The Ameba Wi-Fi Audio solution enables wireless audio transmission with one transmitter and multiple receivers connected via standard 5GHz Wi-Fi. The transmitter receives audio data from a host and manages all connected receivers, while receivers handle audio playback.

Audio Source Input

Transmitter is responsible for receiving audio data from the host controller and transmits it to receivers via standard Wi-Fi. Currently transmitter supports bellowing audio input interfaces:

../rst_solutions/figures/wifi_multispeaker_audiosource.svg

I2S Interface

Most of transmitters use I2S interface to receive audio data. The I2S interface supports:

  • Master and slave mode operation

  • Supports up to 8 channels per I2S

  • Sampling rates up to 192kHz

  • Multi-I/O and TDM modes supported

USB Audio Interface

Transmitters can also function as USB audio devices to receive audio data and transmit to receivers via Wi-Fi. The USB interface features hot-plug capability for convenient audio transmission.

  • USB Audio Class 1.0. Good compatibility but lower throughput.

  • USB Audio Class 2.0. Higher throughput for high-quality audio.

Self-test Audio

  • Built-in single-tone audio generation for transmission to receivers

  • Useful for development and factory testing

Audio Transmission

Transmitters receiving audio data from host, sends it to receivers via standard Wi-Fi. The system uses lossless audio formats with advanced technologies for stable transmission.

Audio Specifications

  • Format: Lossless PCM data.

  • Quality:

    • THD+N < 0.001%

    • Frequency response: 20Hz-20kHz < 0.5dB

  • Channels: Up to 12 for spatial audio

  • Hi-Res Support:

    • 48kHz/96kHz/192kHz

    • 16/24/32bit resolution

../rst_solutions/figures/wifi_multispeaker_thd_freq.svg

Latency Performance

  • Fixed 20ms end-to-end latency (I2S input to I2S output)

  • Meets ITU-R BT1359-1 lip-sync standards

  • Unaffected by:

    • Number of channels

    • Number of receivers

    • Transmission distance

../rst_solutions/figures/wifi_multispeaker_latency.svg

Synchronization

Each receiver and channel maintains extremely low synchronization error (less than 1 audio sample).

  • Ultra-low synchronization error (< 1 audio sample)

  • Inter-device sync accuracy: ±2.7μs

  • Maintained across all receivers and transmitter (if configured for playback)

../rst_solutions/figures/wifi_multispeaker_sync.svg

Robust Wireless Transmission

In wireless audio transmission, stability and reliability are of utmost importance. The system employs multiple technologies to guarantee reliable audio transmission.

  • Interference Mitigation:

    • 5GHz band (5.1GHz ~ 5.8GHz)

    • Automatic channel selection

    • Adaptive frequency hopping

  • Error Handling:

    • Error Correction Code (ECC)

    • Packet Loss Concealment (PLC)

../rst_solutions/figures/wifi_multispeaker_robust_trx.svg

Device Networking

Ameba Wi-Fi Audio provides provides flexible ways for application to accomplish the network pairing between transmiter and receivers.

Bluetooth Configuration

  • Quick network pairing via BLE

  • SDK handles all Wi-Fi connection steps

  • Only requires SSID specification

Custom Configuration

  • Supports application-provided Wi-Fi SSID

  • SDK establishes connection using custom credentials

Device Management

Wi-Fi Audio normally includes serveral receivers. To manage these receiver devices, Ameba Wi-Fi Audio provides several interfaces for application to control and get device information.

  • Centralized control through transmitter

  • Real-time device status notifications

  • Custom messaging between devices

System Features

OTA Updates

  • Simultaneous updates for transmitter and all receivers

  • Fast upgrade completion

Power Management

  • Transmitter and receivers support sleep mode

  • Remote wake-up capability for receivers