The Ultimate Guide to Multiroom Video

"Curioser and curioser!" That's what Alice cried in Lewis Carroll's "Alice in Wonderland" as her legs stretched "almost out of sight."

It also describes the situation facing many integrators as they grapple with how to design, sell and install residential multiroom video installations that often require video signals to be stretched great lengths.

Indeed, confusion reigns supreme as integrators handle technical issues with HDMI (high-definition multimedia interface) and HDCP versus component design. Fortunately, there are some solid business reasons to not ignore the multiroom video category, primarily because the proliferation of less-expensive flat-panel TVs and single-source DVRs have made this an attractive amenity in a connected home.

No longer is it a situation where one video source is tied with one display, like in a home theater environment.

For many integrators, lingering questions -- such as HDMI cable run lengths over Cat 5, active cabling solutions, HDMI switching, 1080i vs. 1080p, the authorization delays for the HDCP content flag to be recognized, IP-addressable video transmission and others -- need to be answered. In many ways, multiroom video owes much of its popularity to the commercial market, where restaurants and sports bars have been strong market drivers.

What Is Multiroom Video?

In its simplest form, multiroom video can be defined as a system wherein video and audio signals from A/V source components are routed to remote display locations. Correspondingly, at the remote locations, these display devices, such as CRTs, flat panels or front projectors, are used to view the A/V sources sent from the headend.

A distributed video system is desirable when there are multiple A/V sources on site, there are multiple display locations and/or the displays are located a long distance from the source.

There are three methods for distributing video:

• Radio frequency (RF)


• Baseband


• and IP.

In an RF distribution system, the baseband audio and video outputs of all the source components are modulated onto an RF carrier. These RF carrier signals are routed into RF combiners and finally into large RF amplifiers for transmission across the distribution system.

The amplifier or amplifiers used must have adequate gain to supply a clean signal to the most-distant display location. The wiring typically consists of shielded coax RG-6 or RG-59 cable.

In an RF system, a coaxial cable home runs to each display location and all the coaxial cables are connected at a headend location with a coaxial splitter(s) and/or combiners. There are also designs based on a single coaxial run with multiple tap points at each display location. In this system, you have a large RF amplifier that can provide enough signal to reach the farthest display location, and you have a modulator connected to each source device. The modulator sends the A/V signals to a specific channel that is tuned in at each of the remote display locations.