Overview

The WiiM Multi-Room Music (MRM) system is a proven, reliable technology that has been deployed since April 2014. It is used in millions of smart speakers and audio devices worldwide, delivering the stability and performance required for commercial environments.

Combining ease of use with reliable multi-room playback, WiiM MRM makes it easy to manage audio across multiple rooms/zones, creating a consistent and engaging listening experience for every listener.

WiiM MRM System Topology and Architecture

LAN-Based System

The WiiM MRM system operates on a Local Area Network (LAN), requiring all devices to be connected to the same router. The system does not depend on the cloud for real-time grouping or playback control. All communication is handled locally within the network via TCP/IP.

Note: Communication is protected via TLS with mutual certificate authentication and audio data is fully encrypted.

Leader and Follower Roles

The WiiM MRM system utilizes a robust "Leader-Follower" architecture to ensure precise coordination across multiple devices.

When you create an MRM group, one speaker is designated as the "Leader" while other speakers in that group work as "Followers":

  • Leader: This device serves as the central hub. It is responsible for obtaining audio resources, transcoding and encrypting data, and transmitting it to other devices. If the Leaderin a group leaves, the group is automatically disbanded.
    Notes:

    The Leader can transmit audio from any of its inputs, such as Wi-Fi, Bluetooth, AUX-In, HDMI-In, and Optical-In, to other devices in the group.

    In specific scenarios where a Follower can access the Leader's playback resources and permissions, it can seamlessly transition into the new Leader role.
  • Followers: These devices join the group created by the Leader. They receive audio streams from the Leader. They can join or leave the group at any time without interrupting the audio playback of other devices.

Perfect Sound Synchronization

The system utilizes a specialized internal mechanism, often referred to as a "Ticks Counter", to align all devices perfectly.

Based on this highly-accurate time alignment, the system also uses resampling and smoothing algorithms to constantly fine-tune the audio playback, preventing any network jitter, audio distortion, or soundstage drift:

  • Dynamic Bitrate: The Leader automatically adjusts transcoding bitrates based on real-time network bandwidth statistics.
  • Intelligent Bandwidth Control: The Leader manages transmission speeds across the group, prioritizing data delivery to Followers with insufficient cache to ensure uninterrupted playback across the group.

As a result, the system maintains the ultra-low latency of less than 150 µs.

Scalability

Currently, a WiiM MRM group supports a maximum of 16 devices.

The WiiM MRM system is designed to be exceptionally lightweight, allowing it to maintain high performance without taxing hardware resources. The system requires only 1~5 MB of RAM (depending on buffer settings) and a 500KB Flash footprint.

Resilience and Reliability

Seamless Auto-Recovery

After a power outage or network restart, all devices reconnect automatically. The existing MRM groups are restored, so you do not need to set them up again manually.

Real-Time Health Monitoring

Devices within a group use a heartbeat mechanism to actively track each other's status. This allows for real-time monitoring of device connectivity across the entire network.

App Control

The WiiM Home app on iOS/Android fully supports the WiiM MRM system. You can use it to group devices and manage synchronized playback. For detailed information, see How to Use WiiM Multi-Room Music to Enhance Your Listening Experience.

Note: Support for the WiiM MRM system in the WiiM Home app for PC is coming soon. We are continuously developing and improving the PC app.

Firmware Updates

The underlying performance and synchronization accuracy of the WiiM MRM system are maintained and improved through regular firmware updates for your WiiM devices.

Once new firmware is available, your WiiM devices will update automatically by default. You can also manage firmware updates via the WiiM Home app. For detailed information, see How to Update Your WiiM Device Firmware Using the WiiM Home App.