Frequently asked questions
How many speakers do I need to cover my audience?
It depends on the coverage angle (dispersion) of each box and how far it has to throw, not just the headcount. A pair of mains with roughly 90-degree horizontal dispersion will cover a typical function room, while a wide or deep crowd usually needs delay speakers or extra tops so the back rows still get useful level. In the planner, drop an audience zone and read the coverage percentage and average SPL, then add or re-aim boxes until the whole zone stays above your target threshold.
Why does my sound get so much quieter at the back of the crowd?
Sound from a point source follows the inverse-square law, so you lose about 6 dB of level every time the distance from the speaker doubles. On top of that, air absorption eats into the high frequencies the further the sound travels, which is why distant audiences hear a duller, quieter mix. Rather than just turning everything up, the usual fix is to aim the tops so their loud on-axis section reaches the back, or to add delay speakers further into the crowd.
What is comb filtering and how do I avoid it?
Comb filtering is the pattern of peaks and dips you get when the same sound reaches a listener from two speakers at slightly different times, so some frequencies add and others cancel. It is most audible down the centre between a left/right pair, where the path lengths are similar but not equal. You reduce it by keeping overlapping boxes close together, time-aligning them with delay, or accepting that the centre aisle will be combed and covering it with a dedicated centre fill. Switch the planner to the interference view to see the cancellation nulls in blue.
How do delay times and phase alignment work for a speaker array?
Sound travels at roughly 343 metres per second, so a speaker one metre further from the audience arrives about 3 milliseconds late. Phase alignment adds a small electronic delay to the closer boxes so the speakers' wavefronts arrive together across your target zone, which maximises low-end summation and tightens the sound instead of smearing it. The planner's phase-align tool calculates these delays automatically from each speaker's distance to the audience zone.
What is a cardioid subwoofer setup and why use one?
A cardioid sub array shapes the low end so it projects forward into the audience and cancels behind the stage, keeping bass off the performers, the mix position and nearby neighbours. It works by delaying and reversing the polarity of a rear-facing box so its output cancels behind the array and reinforces in front. In the planner you can recreate this by spacing two subs, flipping one to inverted polarity, and adding the matching delay, then watching the rear cancellation appear in the interference view.