What is B&O MCL – Master Control Link
MCL (Master Control Link) was Bang & Olufsen's first real link system and was developed in the early 1980s. With MCL, Bang & Olufsen introduced a new way of thinking about audio and video, where products and rooms were connected in one unified AV system that could be operated uniformly throughout the house.
Bang & Olufsen was one of the few manufacturers to work seriously with the idea of music and TV in multiple rooms early on. Where other solutions were fragmented, B&O developed a system where sound, image and operation were interconnected. This system thinking became the foundation for MCL and later for Masterlink and Network Link.
What is a B&O MCL system?
A B&O MCL system makes it possible to distribute sound from a central Bang & Olufsen audio or video system to multiple rooms in the house. With MCL, you can listen to TV sound or music from the main room in other rooms such as the kitchen, bedroom or bathroom and control the system via the B&O remote control.
MCL is a wired link system and differs from newer solutions by being analog and point-to-point.
MCL82 – the beginning of Master Control Link
The first real Master Control Link system was MCL82, developed in the early 1980s and used with the Beosystem 5000 and Beocenter 7000 and 7700. The MCL82 made it possible to control the main system components from another room via a transceiver and remote control.
Early MCL installations also included units such as MCL 30 og MCL 82, which functioned as simple audio-link solutions for passive speakers. These systems were primarily extensions of the main room, where volume and source selection followed the main system.
MCL 2 – The Master Control Link 2 system (1986)
I 1986 became MCL2 introduced as a further development of the Master Control Link concept. MCL2 was used with larger Bang & Olufsen systems such as Beosystem 4500, 5500, 6500 and 7000 and Beocenter 9500.
The MCL2 built on the idea of whole-house music, but expanded the system to also handle video. The system used the same 8mm passive MCL cable, but made it possible to integrate both audio and video in the link rooms.
MCL2 allowed the use of Beolink 1000 and later Beo4 remote controls, so Bang & Olufsen products could be controlled “virtually” around the house via IR transceivers in the link rooms.
| Product | Year of introduction | Remark |
|---|---|---|
| MCL 30 | 1982 | Early audio link |
| MCL 82 | 1982 | First Master Control Link |
| MCL 2A | 1986 | X-TRA Speaker Kit |
| MCL 2B | 1986 | Prototype for BeoVision LX |
| MCL 2C | 1986 | Integration of non-B&O TVs |
| MCL 2AV | 1987 | X-TRA Active Speaker Kit |
| MCL 2P | 1988 | Simple link amplifier |
| ML/MCL Converter | 1995 | Transition to Masterlink |
Local Control System (LCS) and link rooms
The core of the MCL and MCL2 systems is Local Control System (LCS) devicesThe LCS units are placed in the link rooms and act as the connection between the main system and the individual room.
Depending on the model, the LCS units can:
- distribute sound from main room sources
- provide local control via remote control and buttons
- support passive and active speakers
- provide local volume control and local sources
Overview of all MCL products
| Product | Description / function | Comment |
|---|---|---|
| MCL 30 | Early MCL link device | One of the first MCL products, simple audio link with IR control. |
| MCL 82 | Early integrated link amplifier | Early MCL unit with built-in amplifier for passive speakers. |
| MCL 2A | Standard MCL audio link | Basic audio link with IR control. Volume follows the main room. |
| MCL 2AV | AV link with local control | Advanced MCL with local volume control and local source capability. |
| MCL 2B | MCL 2 variant | Prototype A/V link for BeoVision LX. Relay-based audio routing via 3-pin DIN, separate transceiver and independent volume levels. Predecessor to MCL 2AV and Audio Aux. |
| MCL 2C | Early MCL 2 variant | Early version in the MCL 2 series, briefly in production. |
| MCL 2P | MCL link amplifier | Amplifier for passive speakers in link rooms. |
| X-TRA Speaker Kit | Complete passive link solution | Consists of MCL 2A, IR transceiver and mounting. |
| X-TRA Active Speaker Kit | Complete active link solution | Consists of MCL 2AV with Powerlink for active speakers. |
| MCL 2 (platform) | Overall MCL architecture | Collective term for the MCL 2 series. |
| ML/MCL Converter | Convert between MCL and Masterlink | Used to connect MCL systems to Masterlink. |
Brief explanation of the MCL products
MCL 30 and MCL 82 are the earliest products in the MCL family and were used in the early 1980s. They enabled sound in link rooms, but without local volume control and without independent functions. The link rooms functioned as pure extensions of the main room.
MCL 2A became the most widely used MCL unit and formed the basis of many installations. It handles audio distribution and IR control, but volume and source selection are shared with the main system.
MCL 2AV was the most advanced MCL device and introduced local volume control, Powerlink for active speakers as well as the possibility of local sources such as a CD player and tape recorder. It made the link room much more independent.
MCL 2B and MCL 2C are lesser-known variants in the MCL 2 family. They appear in product overviews, but were produced in limited quantities and are rarer in practice.
MCL 2P is a pure link amplifier for passive speakers and is typically used in rooms where simple music playback without extra features is desired.
X-TRA Speaker Kit and X-TRA Active Speaker Kit were ready-made installation kits based on the MCL 2A and MCL 2AV respectively. They made it easy to set up a link room with either passive or active speakers.
ML/MCL Converter used to integrate MCL installations with newer Masterlinksystems and allowed existing MCL setups to be maintained even when the main system was upgraded.
MCL units - technical explanation
| Product | Type | Local control | Speaker type | Local sources | Comments |
|---|---|---|---|---|---|
| MCL 30 | Early MCL | No | passive | No | Before MCL 2 series, pure extension of main compartment |
| MCL 82 | Early MCL | No | passive | No | Integrated link amplifier |
| MCL 2A | LCS audio | No | passive | No | Sold as X-TRA Speaker Kit |
| MCL 2AV | LCS audio/video | Yes (+12dB) | Passive and active (Powerlink) | CD, Tape, AUX | Sold as X-TRA Active Speaker Kit |
| MCL 2B | MCL 2 variant | Begrænset | passive | No | Rare variant in the MCL 2 series |
| MCL 2C | MCL 2 variant | Begrænset | passive | No | Early MCL 2 variant |
| MCL 2P | Link amplifier | No | passive | No | Simple solution for background music |
| X-TRA Speaker Kit | Complete kit | No | passive | No | Includes MCL 2A and IR transceiver |
| X-TRA Active Speaker Kit | Complete kit | Ja | Passive and active | CD, Tape | Contains MCL 2AV |
| ML/MCL Converter | converter | Ja | Depends on system | No | Transition between MCL and Masterlink |
Which MCL device do I have?
If you have an older Bang & Olufsen setup, you can often identify your MCL system by:
- the name of the LCS device (MCL 2A, 2AV etc.)
- whether there is Powerlink-outputs for active speakers
- whether the volume in the link space affects the main space
- whether there are local sources connected in the link room
The most common installations in private homes are based on MCL 2A og MCL 2AV.
Subpages – details about each MCL unit
On the following pages (click on link) you can read more in detail about the individual MCL units:
- MCL 2A – X-TRA Speaker Kit and audio link
- MCL 2B – prototype AV link for BeoVision LX
- MCL 2C – integration of non-B&O TV
- MCL 2AV – X-TRA Active Speaker Kit and advanced AV link
These pages go into depth about functions, limitations and practical use.
MCL as the foundation for later B&O link systems
Although MCL is now an older system, it was technologically forward-thinking. Many of the principles – uniform operation in all rooms, local control and integration of audio and video – were further developed in Masterlink and still forms the basis for Bang & Olufsen's system thinking.
MCL 2P – link amplifier for passive speakers
MCL 2P was a compact link amplifier for passive speakers. It received sound and control via the MCL cable and was typically used in rooms where simple background music was desired without local sources.
MCL cabling – 7-conductor MCL cable
The B&O MCL system is designed as a point-to-point system, where each link room has its own cable from the main room. The system uses a 7-conductor MCL cable, which carries the left and right audio channels, common ground, data bus for control, supply voltage, and control and reference conductors.
This single cable distributes audio, control and power to the LCS units.
MCL as a foundation for Masterlink and later B&O systems
MCL and MCL2 were technologically forward-thinking systems and formed the foundation for Masterlink, where many of the same principles were further developed. Uniform operation in all rooms, local control and integration of audio and video are still cornerstones of Bang & Olufsen's system thinking.
MCL – Master Control Link – FAQ
MCL is Bang & Olufsen's first link system, introduced in the early 1980s. The system makes it possible to distribute audio – and in some cases video – from a main system to multiple rooms in the house, so that the entire home functions as one unified AV system.
LCS stands for Local Control System. The LCS units, such as the MCL 30, MCL 82, MCL 2A and MCL 2AV, are the units that are placed in the link rooms and make it possible to play and control audio from the main system locally.
The most significant difference is the degree of local control.
MCL 2A functions as a direct extension of the main room's audio system, where the volume in the link room and main room follow each other.
The MCL 2AV, on the other hand, provides local volume control in the link room, independent of the main room, with the possibility of up to 12 dB higher sound level locally. In addition, the MCL 2AV supports active speakers via Powerlink as well as local sources.
The X-TRA Speaker Kit was the market name for the MCL 2A and typically consisted of the MCL 2A, an IR transceiver and connection for passive speakers.
The X-TRA Active Speaker Kit was the market name for the MCL 2AV and made it possible to connect active B&O speakers via Powerlink.
MCL systems were often used with passive speakers such as the Beovox CX 50, Beovox CX 100, Beovox 300 and Beovox 5000.
When using the MCL 2AV, active speakers such as BeoLab 3000 and BeoLab 5000 could also be connected via Powerlink.
On MCL 2A there is no option for local sources – here the link room only has access to the main room's sources.
The MCL 2AV can be connected to a local B&O CD player and a tape recorder. The MCL 2AV does not have a dedicated phono input.
In early MCL units, including the MCL 30, MCL 82 and MCL 2A, the volume is shared between the main room and link room. If the sound level changes in one place, the other follows suit.
MCL 2AV introduced local volume control, where the sound level in the link room can be adjusted independently of the main room, although with a limitation of up to 12 dB higher level locally.
The mute button can turn on the sound from standby, mute or reactivate the sound with a short press and turn off the local device or the entire system with a long press.
The timer button provides access to the main room timer function and is often used to automatically start music, for example as an alarm clock in the bedroom.
The MCL 30 and MCL 82 are the first generation of MCL devices and came before the MCL 2 series.
The MCL 30 is a simple audio link unit without local control, while the MCL 82 is an integrated link amplifier for passive speakers. Both act as direct extensions of the main room.
The MCL system uses a 7-conductor cable between the main room and each link room. The cable carries the left and right audio channels, ground, control data bus, supply voltage, and a control and reference conductor. The system is designed as point-to-point connections, not as a common bus.
a, many MCL installations still function stably and are still used in classic Bang & Olufsen homes. However, the system does not support modern streaming without external solutions and has now been replaced by newer link technologies.
MCL was replaced by Masterlink, which further developed the idea of link rooms with greater flexibility, common bus cabling and full local control in each room.