If you are a regular reader of this column, then you have already read some of my writings on Equalization, or, as I like to refer to it, "Frequency Manipulation." I never grow tired of this subject. Mainly because all the sound we hear is made up of a combination of frequencies, and the more control you have over those frequencies, the better you can make things sound. It is as simple as that.
Mastering the Mixer
Like playing guitar, the basics can be learned fairly easily, however, mastering the instrument will take time, commitment and a lot of learning. I know all of you FOH mixers out there are committed to doing your job the best you can. Especially those of us in the worship sound biz. There is a deep desire to serve the congregation and also the God we believe in. At least there should be.
Okay, that said, let's get into Equalization. Before you can adjust a frequency you have to be able to hear and identify it. Look at the EQ section on one of your mixing consoles input strips. Now play a pre-recorded song through your house sound system. Preferably a song that you are familiar with. Something your ears are already referenced to. Now crank up the bass knob. Many boards will show you what frequency you are adjusting. My Yamaha and Mackie boards use 80Hz as the low frequency point.
Turn this knob up and listen to the change it makes. Keep turning it up until it sounds boomy and bad. To much bass is obviously not good. Now, turn the bass knob down until it sounds thin and bad again. Not enough bass is just as obviously bad. Next, adjust the bass (up or down) until you find the "sweet spot" for the bass in that song. We will discuss "sweet spots" of different types later in this article.
Now move up to the high knob on your mixing console input strip and adjust the level up and down until you find the sweet spot. You are training your ears to hear those frequencies with more accuracy. Do the same exercise with all the frequencies on your input strip EQ. Ideally, you should be able to walk into your worship room and easily identify and adjust any unpleasant frequencies.
Once you have mastered the frequency manipulation of your input strip EQ, it's time to graduate to an outboard Graphic Equalizer. You will want to use a 31 band EQ. Should you be operating in Left and Right stereo, you will need one 31 band for each side. It doesn't matter if you use an analog of digital piece of gear, we will be adjusting the same frequencies. Even if you have a digital board, there should be a graphic EQ available on-board. These graphics will be use mainly to tune your FOH speakers to the worship room.
Look at the frequencies bands on your EQ. They will range from 20Hz to 20kHz. It's not a bad idea to memorize them all, with the goal of being able to identify each frequency with your ears. If you accomplish this, you will definitely become an asset to your worship house and, of course, your sound tech friends will look up to you.
Along with the graphic EQ, you will be tuning your worship space with your ears or a real time spectrum analyzer and, possibly, a pink noise generator.
Flatten the Spikes and Dips
The idea in tuning the speakers is to make them heard in the room as flat as possible – without any spikes or dips in frequencies. Many graphic EQs have a real time analyzer incorporated in there graphic display. Some include pink noise generators. In case you don't know, a pink noise generator is designed to provide an accurate, linear noise signal across the frequency spectrum. There are a variety of software packages available for your PC or Mac laptop that analyze frequencies very accurately and there is an app for your iPad that can also analyze real time frequencies. Whatever method you use, you will want to reference as many different areas in your worship space as possible – in other words, listening (analyzing) from the front row, back row, center, balcony etc.
Now that you have your graphic and your analyzing tools and ears, get to it! If you are using a noise generator, plug it into the system and bring up the volume so you can hear it pretty loudly. Get out your listening tools (not necessarily your ears in this case) and adjust your graphic EQ until you are satisfied that the speakers are "flat" as possible in your worship space. There is no doubt that the speakers will sound slightly (or dramatically) different depending on your listening location in the room. Nonetheless, flatten out the speakers as evenly as possible using your graphic EQ.
Should you be armed solely with a graphic and your ears, put up a familiar song through your system and travel around the worship room listening. Increase or decrease various frequencies according to what your ears tell you. There will be a place or places in the worship room where everything sounds perfect. I mentioned this "sweet spot" earlier. This spot can be where the left and right speaker's audio waves converge perfectly – where the entire frequency range can be heard clearly. Generally, the area exists in a space that is equal between your FOH speakers, but not always. Every room is different, and there may be locations where frequencies come together harmoniously without any logical explanation. This may be why the concept of a "sweet spot" is more of a phenomenon than a design feature for speaker manufacturers.
At any rate, you will find at least one of these spots in your house of worship. And if you have adjusted your equalizer properly, you may find that there are many sweet spots in your house.
Though to put your equalizing task into perspective, you really want to adjust the speakers so that the entire room sounds good. This is obviously the best way to serve the entire congregation and God. And this, after all, is our goal, is it not? Good luck…
