Specifications

QuickSwitch HD™ HDMI Switchers Crestron HD-MD8X1/2
HDMI is the new standard for interfacing high-definition AV equipment, and it is
key to handling the latest HD video and audio formats. Crestron has designed its
QuickSwitch HD switchers to provide unparalleled performance, functionality, and
custom integration capability. The HD-MD8X1 and HD-MD8X2 support HDMI
1.3a w/Deep Color and HDCP, handling 1080p60 HDTV and WUXGA computer
resolutions, and multi-channel HD lossless audio.
QuickSwitch HD™ Technology
Crestron’s QuickSwitch HD technology minimizes switching latency that plagues
other HDMI switchers. As the move to digital takes hold, more and more movie
studios and television service providers are using HDCP (High-bandwidth Digital
Content Protection) to protect their DVDs, Blu-ray Discs, and broadcast signals
against unauthorized copying. Viewing the HDCP encrypted content in its full high-
definition format requires the source device to “authenticate” each display and signal
processor in the system through an HDMI connection before delivering an output
signal. Normally the authentication process occurs every time any HDMI signal is
switched, causing a complete loss of signal for up to 15 seconds.
QuickSwitch HD technology achieves very fast switching of HDMI signals by
maintaining a constant HDCP connection with each HDMI device in the system,
eliminating the need to re-authenticate each time a different source is selected.
EDID Format Management
With HDMI comes a variety of video and audio formats to keep track of, and
chances are not every device in a system supports all of the same formats. HDMI
attempts to resolve this confusion using EDID (Extended Display Identification
Data). When two HDMI devices are connected together, the receiving device (a
display or surround sound processor) uses EDID to announce its format capabilities
to the source device (a TV tuner or video player), which in turn configures itself to
output the most effective format that both devices can support.
Unfortunately, there is no guarantee that EDID will always choose the “preferred”
format, and often conflicts arise that can result in disappointing picture and sound
quality. The HD-MD8X1 and HD-MD8X2 take full advantage of EDID to prevent
conflicts, assessing the formats supported by each HDMI device in the system,
allowing the installer to assign only the combinations that work and provide the best
results. Input signal information such as resolution, frame rate, aspect ratio, color
depth, and audio format can also be sent to the control system and displayed on a
touchpanel to allow custom functionality and enhanced diagnostics.
HDCP Key Management
Another aspect to HDCP is its use of “keys” to manage the handshaking that occurs
between any two devices. Every HDMI source device has a limit to how many
downstream devices it can support, determined by the number of HDCP keys it has
available. Rarely is that limit advertised or specified by the manufacturer or service
provider, so connect too many displays or processors and the source will simply stop
outputting a signal without warning.
To prevent such surprises, the HD-MD8X1 and HD-MD8X2 test the HDCP limits of
each HDMI source, allowing the installer to configure the system around any
limitations, or substitute a different component.
CEC Embedded Device Control
The primary objective of every Crestron system is to enable precisely the control
desired for a seamless user experience. The HD-MD8X1 and HD-MD8X2 provide
2 • QuickSwitch HD™ HDMI Switchers: HD-MD8X1/2 Operations Guide – DOC. 6714A