HDMI/DVI-D Splitters and Distribution Amps and Summary
We have already established that HDMI
and DVI TMDS signals can’t be “amplified” in the traditional sense. They can be conditioned to work in a specific
environment through careful active control of impedance and frequency response,
however. Where the TMDS digital video signal
really loses out to analog is in its ability to run to multiple locations. Unlike analog solutions, digital distribution
is always an active proposition that
requires a carefully engineered component.
And digital distribution is limited in the typical installation. A single source can feed as many as four
display devices in the digital domain, but cheap and reliable analog
distribution amplifiers allow a component signal from a single source to be fed
to 4, 8 or more display devices with virtually no penalty!
Another idiosyncrasy of the digital video domain is the necessity of the source and load to work as a system. Because of this, digital video DVI-D and HDMI “splitters” always require a master, or primary, source to lock onto the sync. This means that you can have two plasma displays hooked up to a single HDMI enabled device, but one of those displays will always have to be in use. In other words, you can have TV1 on and TV2 off, or TV1 on and TV2 on. But you can never have TV1 off and TV2 on!
Summary
When planning for, designing and installing a sophisticated media system it is vital to consider the environment and distribution of signals. Music and antenna signals are easy to distribute with a little planning. Baseband video and audio signals deliver a bigger challenge, but are still surmountable with careful analysis. Digital distribution makes demands that challenge even the most experienced integration specialists. Yet even with their varying levels of challenge, it’s incredibly important to get the wiring right. With the right infrastructure you have options and opportunities that might not be attainable once the drywall goes up and the first phase of the installation is done. Distributing HDMI and DVI-D signals expands the efficacy of a high performance multimedia system investment. It’s a big challenge, but one that we can face if we take time to understand the technology.
In our next article – MATV, SATV and RF Infrastructure!
Many thanks to Impact Acoustics for contributing this article
