In a nutshell, in rooms more than 10m x 10m, with audiences more than 50, and where you want to be certain everyone attending has the chance to hear the message equally as well, then choose 4 speakers.

So the value could be as great as, a significant number of people further back in the room, understood and engaged with your talk / presentation, than would have otherwise.

Steven Thompson, founder of ST AV is first and foremostly a sound system engineer, with extensive experience over 15 years in specificing price appropriate speaker systems for certain applications.

From Steven's insight, you may be surprised to learn that often times, in rooms with significant reflective surfaces, by the time you get just a few rows of seats back in a room, people are actually listening to more of the room's reflections, than the direct sound.

In other words, the amount of sound being reflected back off nearby surfaces, exceeds the amount of sound travelling directly from the speaker to the person listening.

What's the problem with that?

The words, especially the consonants, (that's letter sounds like D, B, C, P, T) can get muddied and unclear. And so the meaning of words are less easy to follow.

(We use the example here: these two sentences contain the same number of words, and sound really similar, but have completely different meaning:
"separate the wheat from the chaff" " and
"separate the wheel from the shaft"

(admittedly, sentences that are less common since 1704 😉

But hopefully you get the point: if it's tricky to hear the difference between D's and B's (also a problem in some phone conversations right!), or in this case C's and S's, due to more reflections than direct sound, then the meaning is lost.

Take this talk we provided speakers to for example Places for People, (photo above). It still surprises us that some of our competition only recommend a two speaker PA system for rooms of this size.

You’ve most likely been there. Sat in a large meeting room near the back, or in a hall for a talk, and found your attention increasingly drifting off you find it even harder to concentrate and understand what’s being said. (Obviously there are other reasons why you might drift off in a talk 😉

But let’s go with the presumption that the topic is of interest to you. Then surely it would be helpful if the people who set the sound up, did everything they could, to make sure that as much direct sound reached all listeners, without the distraction of what is usually in a in lay terms referred to as “echo”.

That’s where more than 2 speakers come in.

You’re evening our the distance ratio.

So that more people, are equidistant to a speaker, aka more direct sound.