PA Alignment: What Actually Matters

It’s probably worth saying that all the effort to align a PA system will only be heard by just two lines of people!

That’s quite frustrating, in my modest opinion.

I've used pure geometry and I've calculated where the crossover frequency intersects with phase at 0° with the same number of cycles, and the result is a straight line—even off-center, btw, from the stereo panorama.

In the image above, you can see 8 cycles of 200Hz produced by both the subs and tops. The result are two lines, each 13.72 meters long, that meet at 0° phase where the fifth person is standing. At regular intervals, there are the other points where the phase is also 0°, both in front and behind.

The first person in front of the PA represents the minimum distance at which the same number of cycles (in this case, 3 cycles of 200Hz) can align at 0°.

I tested this using the renowned simulation software Mapp3D by Meyer Sound, and the results confirmed both the calculations and the CAD representation.

Of course, some level of PA alignment is necessary for overall balance. However, my advice is not to obsess over it. After all, a stereo PA can still provide a good experience also for those who aren’t positioned right along the line where the sublime 0° phase alignment occurs.

I personally find the configuration of subs to be far more interesting and important. This is because it affects a much larger portion of the audience due to their inherent power, and getting them in phase can be incredibly rewarding… but that’s a topic for another article, ... maybe.