Invisible AV - How to Plan a Stealthy Loudpseaker Set-up (by Buck Moore)

A traditional loudspeaker set-up for a business meeting might include a left and right speaker on either side of the stage or the use of the ceiling-mounted distributed speaker system already installed in the venue. Often, the former are medium-sized cabinets that can obscure viewing angles and the latter can sometimes sound 'tinny', if not simply cut out sound from time to time (the audio controls are usually pre-set and can collect dust, which can cause the sound to be intermittent even at the finest of venues).

Aside form being very 'present' in a room, medium-sized speaker cabinets can have annoying little lights on the front of them and their larger speaker stands can create extra trip hazards. Using smaller speakers with high audio output can allow the AV technician to create zones of audio and adjust each zone independently and on-the-fly as needed. Also, smaller speakers won't obstruct viewing angles and can sit on smaller stands or even small tables, which are unlikely to be tripped over.

Large speakers at the front are usually only useful for live music and DJ's, where a full sound is desired, but for speaking voices and multi-media, they are very often unnecessary. Ideally, speaker zones should be planned with a combination of powered and non-powered speakers, especially along air-walls, where running power drops to them can be a pain.

Below are two examples of zones created with powered and non-powered speakers from initial planning to implementation:

The bottom example was planned for front projection, but we actually decided to go with rear projection because we had the room behind the screens - it was an aesthetic choice by the meeting planner and would allow for more tables near the front (not to mention the venue politics involved in getting the event up and running).

Using smaller cabinets, distributed throughout the room and aimed properly (to even out levels and avoid audio delay effects) can cover large audiences and minimize the appearance of loudspeakers everywhere. Proper planning of an audio system cannot be left to chance and following these simple guidelines can make your next meeting an AV success!

- Buck Moore can be reached at www.b4ushowit.com.

Invisible AV - How to Hide an AV Set Up and Save Money at Your Next Event

Invisible AV set-ups, where the AV person and main loudspeakers are hidden from view behind the screen, ensure quick reactions by the AV technician to any problems which may arise as well as having the appearance that the show is running by itself.

Two major concerns among fellow technicians include a lack of proper monitoring out front and loudspeakers not on stands, above the ears of the audience - two issues which shall be addressed here.

The following picture illustrates some of the benefits of hiding the audiovisual technology behind the screen (in this case a rear-projection screen) - no cables taped to the floor and no speakers on stands. Showing too much technology tends to look less streamlined, which is why some AV companies and operators insist upon setting up a 'skirted area' at the back of the room so they don't stand out too much, but they are still very much out there.

Going with a rear-projection set-up such as the this won't work in all rooms, however, and must be planned out carefully so that a given projector can fill the screen from behind. The screen shown is a 6 X 8 foot Dalite Fastfold. To fill the screen, there needed to be about 16 feet behind it using a projector with a 1.1:1 zoom ratio, which means the projector lens can make the image 10% larger than the smallest image setting. For rooms with less area behind the screens, a zoom ratio of 1.6:1 would be needed, so that only 12 feet would be needed behind the screen.

The primary loudspeaker was positioned behind the skirt* of the screen and aimed out toward the seated audience, while a second loudspeaker was above the rear half of the audience, aimed down and hidden behind the golden handrail, which is just out of frame to the right. The ideal set-up would have included an audio delay to keep the 'fill' speaker from being noticeable, but turning it lower in volume than the main speaker also works well.

* the skirting for the screen frame should be thin enough to avoid cutting out the higher audio frequencies that are needed for audio intelligibility 

The invisible AV set-up has some distinct advantages over the traditional back-of-room AV set-up, including:

1) There are fewer cables to route to the back of the room - this should save some money** because there is less to set up and there will be no unsightly cables taped to the floor that people can trip over. 

** individual AV companies differ in this respect, so ask a lot of questions

2) The AV technician can respond immediately*** if technical problems should arise - this saves time and keeps things running smoother as the technician doesn't have to run to the front of the room to fix the problem (this is especially important where there are no proper aisles planned when setting up tables).

*** not all AV staff will help with EVERY aspect of the technical side of things - for example, some technicians will not do much about trouble with multimedia playback that doesn't go as planned

3) The projector doesn't take up room in front of the screen - if you decide that rear-projection is right for the room and event, you will not have to worry about somebody bumping into the projector table (or cart), nobody can trip over the cabling and there will be more room for an extra table or two for the audience.

To sum up, the invisible AV set-up is a streamlined way of running the technical side of an event that can save you money on set-up and strike, look as though it is running by itself and has the benefit of less cabling exposed. Even if you must use front-projection because of the room size, you can still minimize exposed cabling and still have the AV technician close by.

Monitoring the event is quite easy as the AV technician can do an occasional walk-around to ensure proper audio levels and, in the case of two-screen set-ups, can angle the screens 'in' to be able to monitor what's being projected from behind a screen (see picture below). The invisible AV set-up is ideal for meetings of up to 200 people where the meeting planner needs excellent results within a modest budget.

Here is one more example of a two screen, front projection set-up at an event for 180 people in New York City:

 

I had a clear view of the presenters and the screen content 

with perfect control of the multimedia playback.

- Buck Moore can be reached at www.b4ushowit.com or email: buck@buckmoore.net