OpenAudio officially launches the exclusive KNX Integration Protocol (Version V1.0, released February 2026) for its HOLOWHAS Series Multi-room Streaming Amplifiers. Based on standard KNXnet/IP text commands for communication and built for the product’s core 8-Zone 8-Source audio architecture, the protocol enables plug-and-play functionality with no complex programming required. It significantly reduces the difficulty of integration with KNX smart home systems and delivers refined, matrix-based intelligent control for whole-home audio setups.
Download the Full KNX Integration Protocol PDF
Core Protocol Infrastructure
Hardware Compatibility
The protocol is optimized for the HOLOWHAS Series’ core configuration of 8 independent audio playback Zones and 8 independent audio Sources, supporting independent dual-dimension control:
- Zone Control: Each playback zone features independent volume adjustment, mute control, and free selection of the audio Source for playback.
- Source Control: Each audio Source supports independent volume adjustment, mute control, and manual selection of physical input interfaces (HDMI, Bluetooth, AirPlay 2, etc.).
Standard 3-Level KNX Group Address Format
The protocol adopts a clear, maintainable Main Group/Number/Function 3-level address structure, defining a unified address rule for all control operations:
- Main Group: Distinguishes control objects – 1 = Zone Control, 2 = Source Control.
- Number: Specifies the serial number of the exact control object (1-8 for both Zones and Sources, corresponding to Zone 1-8/Source 1-8).
- Function: Specifies the type of operation on the object, defined by function codes with core rules as follows:
| Function Code | Operation | Value Range & Description |
| 1 | Volume | 0-255, corresponding to 0%-100% volume (e.g., 128 = 50%, 179 = 70%). |
| 2 | Mute | Boolean value – 0 = Unmute, 1 = Mute. |
| 3 | Selection | 1-8. For Zone Control, selects the Source number; for Source Control, selects the physical input interface number. |
Core Control Specifications
Zone Control Address Table
Covers all Zones 1-8, with each zone assigned three independent addresses for volume, mute, and Source selection (all follow the 3-level address rule):
| Zone | Volume Control | Mute Control | Source Selection |
| Zone 1 | 1/1/1 | 1/1/2 | 1/1/3 |
| Zone 5 | 1/5/1 | 1/5/2 | 1/5/3 |
| Zone 8 | 1/8/1 | 1/8/2 | 1/8/3 |
Source Control Address Table
Covers all Sources 1-8, with each source assigned three independent addresses for volume, mute, and input interface selection:
| Source | Volume Control | Mute Control | Input Selection |
| Source 1 | 2/1/1 | 2/1/2 | 2/1/3 |
| Source 6 | 2/6/1 | 2/6/2 | 2/6/3 |
| Source 8 | 2/8/1 | 2/8/2 | 2/8/3 |
Source Physical Input Interface Mapping
The numeric values for the Source Selection function code (3) map one-to-one with mainstream physical and streaming input interfaces, supporting all core audio access methods on the market:
| Value | Physical/Streaming Input Interface | Value | Physical/Streaming Input Interface |
| 1 | LINE IN | 6 | Spotify Connect |
| 2 | HDMI ARC | 7 | Google Cast |
| 3 | SPDIF in | 8 | DLNA |
| 4 | Bluetooth | 9 | Qobuz Connect |
| 5 | AirPlay 2 | – | – |
Standard KNXnet/IP Command Format
The protocol uses a unified write [Address] [Value] command format with no additional complex syntax, executed directly via KNX bus broadcasting. Core control examples are as follows:
Zone Control Examples
- Set Zone 3 volume to 50%: write 1/3/1 128
- Mute Zone 5: write 1/5/2 1
- Switch Zone 8 to play from Source 3: write 1/8/3 3
Source Control Examples
- Set Source 4 volume to 70%: write 2/4/1 179
- Switch Source 2 to HDMI ARC input: write 2/2/3 2
- Switch Source 7 to Google Cast: write 2/7/3 7
- Mute Source 6: write 2/6/2 1
Streamlined Integration Process & Core Advantages
Configuration Responsibilities (No Programming, Plug-and-Play)
Designed with a Transparent Receiver + Address Binding Only architecture, the protocol clearly defines configuration duties for the audio system and KNX controller, eliminating complex engineering setup:
- OpenAudio Audio System Side (Receiver & Executor): Automatically monitors the KNX bus for incoming commands and parses addresses and values. No configuration required (no ETS software, no database import) – true plug-and-play functionality.
- KNX Controller Side (Sender, Panel/Hub): Only needs to complete binding of physical buttons/sliders to group addresses in the ETS Engineering Tool Software (graphical operation, similar to setting shortcuts). No coding or KNX system redesign is needed.
Complete Control Flow
- The user performs an action on the KNX panel (button press/slider adjustment).
- ETS triggers the pre-bound group address and corresponding value.
- The standard write [Address] [Value] command is broadcast over the KNX bus.
- The OpenAudio amplifier receives and parses the command.
- The amplifier executes the corresponding operation (volume adjustment/mute/Source switch/input switch).
Core Protocol Advantages
- Standardized Structure: Built on the standard KNX 3-level group address design, compatible with the KNXnet/IP protocol and all mainstream KNX smart home systems.
- Refined Control: Full independent control of 8 Zones and 8 Sources with precise 0-100% volume adjustment, meeting the demands of complex whole-home audio scenarios.
- Rich Interfaces: Sources support both physical interfaces (LINE IN, HDMI ARC, etc.) and mainstream streaming interfaces (AirPlay 2, Google Cast, etc.), adapting to all audio access scenarios.
- Lightweight Integration: No programming, zero configuration (amplifier side) and only address binding (KNX side), drastically reducing integration difficulty and engineering costs.
- Seamless Compatibility: Based on the core KNX group address communication rules, seamless communication is achieved as long as both parties follow the agreed address and value definitions – no cross-system compatibility issues.
