Audio Everywhere provides Wi-Fi Audio in sports bars and similar locations. We recently surveyed the companion challenge of video distribution and found the solutions diverse.
Generally, hundreds of channels on one or two RF (radio frequency) coaxial cables from a satellite antenna or cable come into the establishment to be distributed to a multitude of TVs.
The challenge is getting the signal from its venue entry point to the correct TV.
Here in Part 1, we illustrate five typical cases. In Part 2, we evaluate the pros and cons of each method.
For all cases we naturally assume that the audio goes to an Audio Everywhere stream-audio-to-smart-phones-over-Wi-Fi system. Audio over the PA (public address) system is typically sourced just from one main TV tuned to the home team channel.
We discuss possible vendors just to get you started. They’re not vetted and offerings change all the time. Caveat emptor.
The diagrams with these examples use the convention of blue for video, red for audio, and green for control.
Starting simple: A receiver behind each TV
Figure 1 illustrates running the RF (radio frequency) cable to each TV location.
This example assumes one source, e.g., a satellite receiver, though easily generalized to multiple providers. Splitters pull a copy of the signal off the cable.
Signals go into specialized receivers, R, that contain decoders, allowing for the copy protected content to be shown by the licensee.
Since the receivers are near the TVs, a short HDMI cable to the TV allows the highest quality image. Channels are changed on the receiver, not on the TV, which is tuned to an unchanged input such as “HDMI2”.
Sports bars with multiple rooms often have two back-to-back TVs driven from one receiver, requiring an HDMI splitter. This introduces the topic of HDCP, High resolution Digital Content Protection, designed to prevent the use of high-resolution content going over HDMI in ways that conflict with the license. HDCP issues plague many installations. If your splitters and HDMI extenders do not seem to work, HDCP is your most likely problem. Test any system that uses HDMI carefully at all resolutions you will use.
Since audio sources have no easily accessible central point, the audio must be retrieved from the TVs to the Audio Everywhere server. The best audio gathering place is from the receivers, which usually have red and white RCA analog line-out connectors. If the length back from the TV to the Audio Everywhere venue server is less than about 10 meters, it is easy to use shielded audio wire to bring the sound back to the location with the Audio Everywhere appliance. For longer runs, it is better to use balanced signals that are created using an inexpensive device called an audio balun.
This system’s key advantages are simplicity and robustness. One disadvantage is the requirement to dispatch wait staff to point the remote control at (only) the correct receiver, not a good use of their time. Also, 25 TVs running 8 different channels generally require 25 rather than 8 receivers, each with a monthly charge.
Using a multi-input receiver
The previous example required a receiver at each TV to decode the protected cable or satellite signals. Several vendors provide systems that will decode the signals and output them on a coaxial cable to be received by a basic TV, creating a private cable network in your establishment. To see eight stations at a time the multi-input receiver takes the hundreds of protected input channels off the cable input and outputs eight channels as selected by the bar. Tune the TV to one of those channels and you see one of selected eight. (Figure 2).
Both ZeeVee and TechniColor offer systems to accomplish this. Audio is done in the same way as in the last example.
A very common arrangement consists of satellite or cable feeds coming into a common area to be fanned out to a rack of receivers (Figure 3). The HDMI signals, only good for short range, must be converted to a different electrical format that will carry the signal a long distance. These interface devices are called HDMI “baluns” or “extenders,” differing from the audio baluns mentioned above.
The outputs of the converter range from composite video to component video to compressed video over IP to lossless HDbaseT.
Figure 3 shows converting from HDMI to Video on CAT6 and then back again. Digital is now the highest quality transport mechanism and it gets better and less expensive every year. On the other hand, component video over CAT6 is a cost-effective solution for sports bars that don’t need the highest resolution.
One advantage: You only need one receiver for each chosen channel. A typical US sports bar needs at least eight receivers because of NFL football.
Conveniently, the Audio Everywhere venue server can be placed in the same rack as the receivers.
For control, one can use any number of controllers from Control4 to AMX and Crestron. At the very least, use an RF controller such as those offered by Home Theater. Specialized controllers, e.g., DirecTV, run on an iPad and will control any DirecTV box on the local area network.
We can put a video matrix, up to about 16x16, or gigabit Ethernet switch between the receivers and the TVs for ultimate flexibility. The Ethernet switching method is relatively new.
Here we represent how advanced functions such as tiling TVs together to form larger images can be accomplished.
These systems, and the previous ones, can be used to allow one receiver to drive multiple TVs, HDCP permitting.
SportsbarTV has a cute system where their controller can throw any program onto any TV. Thus a patron sitting near TV4 can request a game that’s playing on TV17. A couple of taps on an iPad and the deed is done.
Video over IP
Video over IP is the new new thing in video distribution; it comes in proprietary or standards-based formats. Historically, the proprietary formats come first and are eventually supplanted by standards-based solutions. The two standards fighting it out now are HDbaseT over IP and Software Defined Video over Ethernet (SDVoE). The key enabling technology is 10 Gbit Ethernet, which allows even 4K video (the highest resolution TVs commercially available today) to be carried without compression. Video over IP works even for 1000baseT (Gigabit) Ethernet, but one must compress High Definition video to make it fit.
Video over IP’s attraction is that it uses standard networking components for much of the heavy lifting and these prices push inexorably lower. It uses standard Ethernet switches to direct the signals around. Special devices are only used at the edges of the network for transmitters (conversion from HDMI to Ethernet) and receivers (Ethernet to HDMI). The usual controller companies have systems for managing the Ethernet switches.
Thanks to the following for their advice and teachings, Richie Normand of RichieAudio, Rick Marks of Homesmart Central, Jeff Graham of Alaska DTS, and Jeff Mayes of Sportsbar-TV. The insights are theirs and the mistakes are mine.
Go to Part 2.