Line array or point-source speakers: when to choose which
A common question when renting speakers is whether a bigger event needs a line array or whether a pair of good active speakers will do. The answer depends less on the headcount than on how deep the audience is and where the speakers can stand. Here we explain what a line array does, what it demands, and when the simpler solution is the better one.
Point source: one box, one direction
An ordinary point-source speaker, such as a JBL SRX812P on a stand, radiates sound from a single point. The further away the listener, the quieter it gets, and it happens fast: the front row is loud while the back of the hall has to strain to follow a speech.
In a small or medium room that is not a problem, because the distance between the first and the last listener is small. Two SRX812P on stands cover an ordinary hall of up to three hundred people, which is why we use them in the conference kit for up to 300 people and in the outdoor event kit.
What a line array does
A line array is made of several identical elements hung or stacked one above the other, each at a slightly different angle. The lower elements point down at the nearby audience, the upper ones far out. The result is that the level drops much more slowly with distance, and the back row hears almost as well as the front.
The second gain is control: the sound goes into the audience rather than onto the ceiling and walls, so speech stays clearer in a large reverberant hall. Our concert kit for up to 500 people has six JBL VTX A8 elements, three per side, standing on a VTX A8 BP base plate on top of two VTX B28 subwoofers.
Audience depth decides
The right question is not how many people, but how far the last listener is compared to the first. A wide, shallow room where the audience sits at roughly the same distance from the speakers works with point-source boxes, two pairs if needed. A long hall or an outdoor field where the crowd stretches far back is line array territory.
Height matters too. A line array needs height for the upper elements to see far. A ground stack on subwoofers gives less of it than flying, but often enough.
Flying or ground stack
Flying needs rigging points in the ceiling with a known load rating, an array frame (JBL VTX A8 AF) and a person who knows the work. In return the array gets up high, the front rows do not block it and the coverage is more even.
A ground stack is faster and needs no rigging points: the elements stand on the base plate on top of the subwoofers beside the stage. Up to five hundred people this is usually a good solution, especially when the stage is raised. For a larger and deeper crowd it is worth discussing flying.
Amplifier, processing and a technician
The VTX A8 and B28 are passive, so they need separate amplifiers: the concert kit has a Crown I-Tech 4×3500HD for the array and a Crown I-Tech 12000HD for the subwoofers. The amplifier holds the processing preset for each model, the element angles are calculated in software before the event, and the whole system is tuned on site.
This is not a kit you collect from the warehouse and put up yourself. For a line array we always recommend setup with our technician, and we quote that on request. Active speakers on stands are the opposite: connect power and signal and they play.
A short decision aid
If in doubt, start here and write to us when your event falls between two lines.
- Speech or presentation in a hall for up to 300 people: two SRX812P on stands, no line array needed.
- Party or DJ for up to 200 people indoors: SRX812P with SRX818SP subwoofers on distance poles, as in the party kit for up to 200 people.
- Concert, deep audience or outdoor site for up to 500 people: the concert kit with line array and technician.
- A medium hall where the audience is long but not large: the smaller JBL VTX A6 array can be the right middle option.
