Concert sound is filled with as many opinions as there are available audio solutions. Whether it is the argument of quality versus convenience and coverage for point source versus line arrays, or the virtues of in-ear monitors over wedges on stage, there are discussions to be had at every point on the signal chain.
One point of contention that always creates debate is how subwoofers are deployed. Should you keep the energy on the floor and deliver that tactile sense of bass to the crowd with a ground-stacked solution? Should you aim for more volume control with a flown sub array? Or should you perhaps look to do both to really lay on the low end?
Flown subs do give you a number of advantages. By flying your bass rig behind your main array, you are freeing up valuable floor space that can either be used as part of the performance area or provide extra seating to sell – a vital element for every commercial production. Equally important is the control flown subs can give you. By deciding to fly your subwoofers you will have more even volume control across the whole space and more accurate timing to combine your main PA and your low frequency support.
While these are strong positives, there are just as many counter arguments. Ground-stacked subs will be about 3dB louder than flown subs and there is less chance of significant sound leaking onto the stage due to the dispersion pattern of flown arrays. There is also the fact that if you add subs to a single hang you are reducing the number of mid-high cabinets you can fly for your main array by adding the extra weight to your flying points. Staying with the purely practical viewpoint, deploying a ground stacked sub configuration will also be quicker than flying subs safely, an important factor to consider when load in times are restricted. Perhaps the most important element against flown subs is that they tend to lose their punch. The extra distance from the crowd tends to play a role in reducing the energy felt from a flown low frequency array.
The honest truth is that there is no right answer to this question, and it very much depends on the venue. The best option is to consult with an experience pro audio company, like Prosound, which will be able to help design the correct system for any venue.
Get in touch to see how we can help.