Demystifying the technology of A/V – PART 1

We all know that A/V is the necessary evil in any meeting or event. It is a mystery as to why they have to charge what they do and how do they really determine what you need? Early on my career I actually worked in Audio Visual sales for Total Audio Visual Services which then became Caribiner and I have lost track of what they are called now. I didn’t really end up in the job that I had applied for, but that is neither here nor there. I still can’t figure out how to connect the DVD to the DVR to the TV and make the correct remote control work, but I did learn enough to be dangerous and to help me to be a good negotiator in regards to AV.

Let’s start with a few basic fundamentals about what some of the basic gear is:

Wireless Microphone Kit – it is a called a kit because it offers you a choice of 2 microphones (either a handheld microphone or a wireless lavalier microphone). You can only use one of the mics at a time though. Because they are wireless, they run on a wireless signal and that signal is the same for both mics. Therefore, if you try to use them both at the same time they will cancel each other out. They are beneficial in that if you don’t know the preferences of the speaker or your agenda has a variety of speakers and audience Q&A, they provide you with the ability to be versatile.

Mixer – and I’m not talking about the one that is in your kitchen! This is an essential piece of equipment if you have more than one microphone in use. In most hotels you can plug one microphone into the house sound and there should still be a volume control in the room for the mic. If you are using more than one mic, you need to have a mixer. Think of it as a “power strip” of sorts where you will plug multiple mics into this box and then this box will connect to the house sound. Mixers can come in several ‘sizes’ or what are called “channels”. You will most often see 4-Channel mixers, but they can go up to 22-Channels…think of how many mics you would have for U-2 or some other band!

Plasma vs. LCD

A plasma screen is a combination of neon-xenon gas which is sealed in plasma. The gas is electronically charged and when the charges strike the red, green and blue phosphorus it creates the image you see on the screen. They are also called ‘pixels’. Plasmas are similar to the old-fashioned tube-style TV’s in that they generate heat but are more streamlined since they are flat.

An LCD (or liquid crystal display) is made up of 2 transparent labels that are polarized and glued together. One layer is treated with a polymer that ‘holds’ the liquid crystals. An electric current is passed through the crystals. The crystals will either pass or block the light to create the image you will see. They use less power than a plasma and therefore, generate less heat.

Both Plasmas and LCD’s present their own set of pros and cons. Plasmas are not as bright as LCD’s so if you are in a very bright location (meeting room with lots of windows or outside, perhaps) an LCD is a better choice. Hence, why most outdoor screens and those new fancy billboards are all LCD’s.


Next up…how do you decipher the AV proposal from the hotel??

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