Additional Aspects

When adding subwoofers to the main arrays, a similar process can be employed. Capture a frequency response trace near FOH, then turn on only the subs, and you can (after time alignment) work with a low-pass filter (LPF) on them or a high-pass filter (HPF) and the mains (or both) to get these two loudspeaker zones to overlap just enough to provide you with your desired final curve.

There are obviously many opinions and preferred processes here, so I’ll just focus on what I like to do because it’s worked well for me throughout the years: Overlap the 50 to 100 Hz range of these two zones if that’s what you like, or have the subs only cover the 20 to 60 Hz range and let the main arrays do the rest. It’s really up to you and your particular preferences.

To summarize, removing unnecessary overlap between loudspeaker clusters, especially in the lower frequency range, will tidy things up unbelievably on stage and in the tech areas behind the PA. There will be the full-frequency “magic” you’re looking for out front while minimizing the amount of undesired low-end “muddiness” on stage and in the room.

Win-Win Scenario

As live sound engineers, our goal should always be to provide the absolute best full frequency mix to the paying public in the seats out front, but by employing some of these techniques, we can also make it much clearer and cleaner on stage for the band and techs.

You may even find that the monitor engineer will return the favor by using a HPF on the wedges and side fills to clean up stage rumble (which, by the way, messes with the PA’s clarity). All the monitor engineer has to do to fill things in on stage is utilize the low end that’s naturally coming off the back of the PA.

Some loudspeaker systems are better at this than others, and some rooms are built in such a way that you’re fully engaged in a battle of wits and will to control the low end, but try using these techniques and tune with a 360-degree mentality, paying just as much attention to what comes off the backs of the loudspeakers as what comes out the front. I think you’ll find everyone will appreciate it,

If your artist on stage really appreciates it, you may just get a raise, and if the crew is grateful that things have cleaned up, you might not have to sleep with a motor in your bunk!