Nov 2, 2010 10:54 AM, By Bennett Liles
In the analog days, the living was easy. We could just twist some cable together, stack adapters until they looked like a Russian space ship, and plug the whole thing in, and it still workedor at least sort of worked. With digital video, a lot more can go wrong, and HDCP has added a whole new minefield, so when everything isn’t just rightnothing. The challenge facing HDMI distribution gear is not only to present spotless video and sound to users but to pass EDID and other communication, of which most users are not even aware.
Methods range from splitting the output of one chip to deserializing, reclocking, and independently repeating the signal at each output. The method can mean a difference in performance when it comes to the distance the video can be run, how many stages through which it can be successfully cascaded, and whether it will even work at all with some displays. The models surveyed here use various means for processing signals, and one or more of the entries will suit just about any possible price/performance scenario for HDMI signal distribution.
For HDMI 3.1, HDCP 1.1, and DVI-compliant signal distribution, the AT-HD-V112 1x12 HDMI distribution amplifier from Atlona features deep color support up to 12 bits, 1080p at 24/60Hz, independent HDCP keyset for each output, and support for HD audio in Dolby Digital TrueHD and DTS-HD. For display compatibility, the unit records EDID from the first display it detects, and at 1080p resolution, the video can be run up to 50ft. without degradation. The unit is housed in a rackmountable black metal case with one female Type A connector and 16 numbered output ports among which up to 12 displays can be run.
Supporting up to 12 bits per color, HDCP 1.1, Dolby TrueHD, and DTS HD Master Audio, the 1398A from Audio Authority provides an eight-way amplified and equalized split for a single HDMI 1.3 source. The cable length may extend up to 100ft., and the units may be cascaded up to seven layers for longer runs with display resolution up to 1080p with lip sync compensation. The 1398A can originate EDID for the source, or it can retransmit the EDID from a downstream HDMI sink. The front panel includes a power LED along with HDMI/DVI, HDCP, sync indicators, and connection LEDs for each output.
The AC552A-4 from Black Box Network Services can split one HDMI source to as many as four displays at 1.65Gbps for 1080i or 1080p to a maximum distance of 40ft. The AC power is autosensing for operation on either 50Hz or 60Hz AC. There is also an output for 9VDC at up to 1 amp, and the mean time between failures (MTBF) is estimated at 95,000 hours. Up to three units can be cascaded for more outputs, and the signals are buffered to allow distribution without signal loss.
Compliant with HDMI v1.3b for deep color and sending video up to 32ft. from each of its eight outputs to the display, the CE Labs HA8-3 supports display resolution up to 1080p and may be cascaded up to seven layers deep. The metallic unit uses all female Type A HDMI connectors, and it has a plate on the cable side with holes through which cable ties can be run to secure the HDMI cables once they are connected. The case can be bulkhead mounted using slots provided in the metal housing, and the unit also provides LED indicators for power and port activity.
The Comprehensive CDA-HD400 1x4 HDMI distribution amplifier handles 165Mhz bandwidth video and supports 480i SDTV. Featuring HDCP- and RoHS-compliant processing, the unit may be cascaded for longer reach to display devices with HDMI 1.3 signals. The 10in.-wide chassis accepts a 5VDC power supply at 2 amps, which is included.
Handling 1080p60 and WUXGA resolution for HDMI 1.3a with deep color, the Crestron HD-DA-2-Quad distribution amplifier sends each of four HDMI sources to two displays independently, and it is compatible with DisplayPort Multimode and DVI with adapters. The unit uses internal EDID management to provide the source device with a compatible display ID for both destination devices. The HD-DA-2-Quad can also use Crestron’s Toolbox software to test the HDCP limits of each source in assuring compliant operation. There are also LED digital sync indicators on each input channel to show that a valid HDMI signal is connected. The rackmountable unit includes a 24VDC power supply, or it may be powered through a proprietary Cresnet connection.
Acceptable Use Policy blog comments powered by Disqus