Treating your speakers right

In the typical American church service, you begin with a band and have to mix a couple of songs, then you get to the “easy part” where you turn on the pastor’s microphone and take a break while he speaks. But I would argue that it is so much more important that you get the volume and EQ just right for a speaker teaching the word of God than it is during the live music part of a service. For one thing, a band has multiple voices and instruments that compliment each other and even draw attention away from mistakes. But when a person is up on stage speaking, there is just one microphone on and that is the sole focus that everyone is hearing in the audience.

The overall rule is still the same – you want to be an unnoticed and invisible part of the equation. The best way to accomplish this during the sermon is to get the volume just right so that each and every person listening feels like they are in a small room hearing the pastor or teacher speaking directly to them. If the volume is too loud, they will feel like they are in an auditorium listening to a sermon with hundreds or thousands of others. In other words, if a pastor sounds like he’s going through a sound system and attention is drawn to how loud it is, you missed that mark of excellence. You also draw more attention to the sound system (vs the content of the message) when the volume is too low, leaving people wishing they had sat more up front and they might be missing words and parts of the teaching.

When the Holy Spirit is blessing the speaker with right words to say, and you have the volume just right, then you get the positive feedback of hearing people as they exit the building saying things like, “It seemed like he was speaking directly to me.”

Likewise, it is so important to get the EQ just right for that single microphone. Otherwise members of the audience may have a stray thought or two about how the microphone sounds like it’s going over a telephone or that the speaker is utilizing a tin can. The goal is to get the EQ settings just right so that it sounds like the person is speaking to you without a microphone or sound system at all.

You know how you can give people a “blind taste test” by blindfolding a person and then giving them two samples of a drink or certain food to see which they like better or whether or not they can tell a difference between Coca Cola vs Pepsi? Imagine a blind sound test. You will know that you have the volume and EQ settings absolutely perfect if a blindfolded person can’t tell how far away the pastor is or if he is even using a microphone at all. People who close their eyes during a message should be able to imagine the speaker standing a couple feet in front of them just sharing the words on their heart to the people next to them.

It is impossible to design an auditorium or sound system that can accomplish that level of perfection for every single seat in the house. But with the right loudspeaker placement and a knowledgeable person behind the mixing console practicing at getting the volume just right, it should be possible to make yourself completely invisible to most of the members of the audience.

Some of the common obstacles against such transparency include:

• The loudspeakers being too low. When you increase the volume for the sake of the people in the rear of the auditorium, you end up making it too loud for the people in the front. Keep this in mind, especially since you will likely be controlling the volume from the rear or very back of the room. It is likely that the best volume is achieved when it sounds too quiet in the sound booth area. The higher the loudspeakers are mounted, the more similar the distance sound has to travel whether to the people seated in front or rear of the auditorium. You can also setup extra sets of speakers set farther back. In either case, you should get an experienced consultant involved when your church is deciding where to mount speakers or how many sets should be used.
• Echoes and reverberations – Sound travels relatively slow, and it does bounce off the walls and ceilings. When you hear the same sound waves coming from the speaker and again after they bounce off the rear walls or ceiling, it tends to give the speaker a “muddy” effect and can make it hard to discern individual words. In some rooms, certain frequencies may be more likely to bounce and echo than others, which may require you to compensate by cutting those frequencies on the EQ. If this is a common problem in your church, you may want to look into more sophisticated equipment such as a parametric EQ which allows you to modify a narrower range of frequencies and be less noticeable if you have to compensate for a room that reverberates too much.
• Microphone placement – The best type of microphone to have for someone teaching is an earset style, generally known as a “Countryman” microphone. It is a razor thin flesh colored microphone that hangs over a person’s ear and sits right at the corner of the speaker’s mouth. Unfortunately these are still quite expensive, so the most common type of microphone you will likely be working with is a lavalier. These are the wireless microphones you see clipped to someone’s tie or jacket a couple of inches under the speaker’s mouth. The biggest problem with lavaliers is that once you’ve found the perfect volume, the speaker will turn his head or look down at the podium which completely changes the volume in the microphone and ultimately the room. So pay attention and turn down the volume if you know the person speaking is going to be looking down to read, and you might need to increase the volume if that person turns his or her head to talk about something on the side of the stage (such as a chart or content projected on the screen). In this case, a compressor would be a useful piece of equipment that can handle such volume changes automatically.
• “Essing” – If you notice how often the words end in an “s” sound as a person is speaking, you may need to de-ess the EQ. The “S” sounds and certain other emphasized consonants, or extra hissing or static like sounds can be reduced by turning down the high or upper-mid range frequencies on the equalizer.
• Leaving the room – I’ve visited some churches where the sound person gets up and leaves the auditorium after turning on the pastor’s mic. While it may be true that the mixing console doesn’t need a baby sitter and hearing the message being taught once during the first service is enough, I recommend that you do stay during all services. You may find the message “boring” by the fifth time you’ve heard it, but if you try you may learn something that you missed the first four times. This way you can be proactive in making sure that lavalier microphone sounds its best. You can be more responsive if something goes wrong, such as a wireless microphone suddenly going dead or picking up intererence. You can be ready to prevent feedback if the pastor spontaneously decides to make his message more interactive and walks in front of the stage and into the audience, etc. The same may not be true if your church utilizes video sermons, microphones are always open to surprises and risk of feedback, prerecorded video doesn’t include too many unexpected audio changes. One final point to consider: in recent auditorium designs, the mixing console is set 2/3rds or 3/4ths of the way from the stage in the middle of the audience. When you get up to leave a few minutes after the sermon starts, you changed your status from unnoticed to noticed for the people seated behind you.

But godliness with contentment is great GAIN

In addition to frequent mentions in the Bible, Gain is also a knob on the standard mixing console (also called Trim). You’ll also find a gain control on most amplifiers. For many guitar amplifiers, gain is the only form of volume control. But don’t let this confuse you, it is an input level and not necessarily an output. If it is your only volume knob, then yes, it directly affects the output volume. But on the standard mixing console, the gain works in relationship with the EQ and Fader to decide what the volume is for a given channel.

You need a gain control because different types of audio inputs have completely different volume levels. For example, your typical microphone produces a very weak signal and requires the gain to be turned up at least half way in order to be heard or even start to cause the meter to start registering. On the other hand, MP3 players can have a rather loud volume (depending on its volume knob) and needs to have a minimum amount of gain. (In fact, there’s usually a “Pad” button next to the gain to turn down these high level inputs even more).

There’s two ways to decide on how to set the gain level. I’m not in the position to say which is right or wrong, though I do have a preference. The audio engineer in charge at your particular ministry may have his or her own preference that you need to follow.

Option 1) Set the gain using the meters on the console. Fancier mixing consoles may have a meter above every channel so you can visually see the level of sound coming in to the channel. Other consoles require that you press the Solo or PFL button to see the input level on a meter in the center or right edge of the console. While visually monitoring the level on a channel, your goal is to get the gain high enough so that the meter is responding to more than just the first green light, but low enough so that it only peaks occasionally in the yellow. If you get into the red, the sound will distort. So make sure you test the channel at its loudest to verify that you have turned the gain down enough.

With this method, you end up with all the channels being about equal to each other. In other words, if you set the fader (the main output volume for a channel) to the same place for a microphone and guitar, they get amplified at about the same volume.

Option 2) Use the gain to set the volume you will generally have that channel at. Imagine you have two guitar players, one is playing the lead/melody parts, and the second is just doing rhythm. During the concert/worship, you’ll want the rhythm guitar to be quieter than the lead so it hides in the background and enhances the music. If you set the gain according to option 1, then you will have the fader for the lead guitar set to 80% or so, and the rhythm guitar set to about 55% output level. But you can also turn the gain down for the rhythm guitar and set the fader equal to that of the lead guitar. This way you can have both faders set to about 80%, but the balance you want between the two guitars is still there (because the gain is lower, the rhythm guitar will be quieter).

This method is particularly useful on the lower end boards that do not have a Mute option on the individual channels. When your only method of silencing a channel (instrument not in use, turning off a microphone, etc) is to turn the fader all the way down, then it is helpful to know that when you bring the channel back up, you can set it to the same volume level as every other channel, you don’t have to memorize the different output levels for different instruments.

Such a method does not provide as much benefit when you can mute the channel without losing your place (you can leave the fader up and simply tap the mute button to silence it), or when you can program scenes that automatically change volume levels based on preset mixes (odds are you won’t run into these types of consoles as a new volunteer).

As you gain experience (pun intended, sorry), you’ll likely find yourself in a balance between the two options and not necessarily strictly adhering to one method or the other. Using the LED meters is a great way to start when trying to figure out where to set the gain knob to. And as the rehearsal progresses, you can adjust the gain as you hear the differences between the instruments and their parts, or just fine tuning different singers with their own different energies.

Don’t forget: EQ also affects input level. If you get the gain set just right so it peaks in the yellow, but then turn up one of the frequency knobs, you may end up in the red after all. What’s EQ you ask? Hopefully I’ll get into that in a future post/chapter.

Feedback 101

My kids are homeschooled and meet regularly with other homeschoolers.  Recently they decided to put on a talent show and I had the opportunity to sit behind the sound board for the event.  Unfortunately I couldn’t make it to the dress rehearsal because of work conflicts, so I had to wing it when I did finally get there.  My wife was involved and warned me that one of the kids who was wearing a wireless microphone might approach another microphone during a drama, her fear being that the two microphones meeting would cause feedback. 

 That’s the inspiriation for starting off with a post on where feedback comes from, because two microphones meeting does not cause it (but two microphones can be out of phase and cause an entirely different problem…a later discussion).  Being too close or too far from the microphone doesn’t cause feedback (but it is a factor). 

Feedback is a result of an output and input crossing paths when they shouldn’t.  A microphone is an input, and a speaker is an output.  If you put the two together, you can end up with feedback.  What happens is that a sound comes out of the speaker, gets picked up by the microphone, goes out of the speaker, gets back in the microphone, and this loop happens so fast that you end up with a loud noise that gets louder and louder. 

And it isn’t just microphones that can cause this.  Sometimes guitar pickups can cause feedback.  Another source can be computers.  I use my laptop for just about everything when I’m working on the production side of an event, I record the event, play pre-show music, sometimes play video clips, etc.  Recording and playback at the same time works fine, unless I forget to mute the Line In…that’s when the audio coming in (the record feed) goes right back out the computers output, which in turn goes back into the record feed, and you get a somewhat loud constant beep.  It doesn’t sound like regular feedback because the volume is fixed at whatever the computer and record feed are set to, there are no variables of distance between speaker and microphone. 

I could write pages and pages on what to do to prevent feedback, how equipment such as compressors can intervene, and so forth.  Needless to say I will revisit this topic again.  But here’s some tips to start off with:

When a person is holding a microphone that starts to feedback, their natural response is to pull the microphone away from them, or they might think they are speaking too loudly.  But the opposite may be true, because the speaker/singer is too quiet, the sound guy turns up the volume, which makes the microphone more sensitive and possibly start a feedback loop.  If the speaker/singer can be louder, the volume on the console can be turned down, and the loop be broken.

If there is a speaker facing the microphone (monitors, or house speakers if the person is in the audience), it may be necessary to turn down those speakers to control the feedback.  For example, if a person speaking is out in the audience and walks to the left side of the room in front of the main speakers, the sound guy can turn the PAN dial (kind of like a balance, tells the channel which speaker to come out of) to the right speakers so that the left speakers are quieter, and the right speakers compensate. 

Once you become more familiar with compressors and equalizers, those will also be your best tools in preventing/controlling feedback.  For example, in certain environments you can have problem frequencies, certain tones or pitches reflect off the wall or ceiling back to a microphone sooner than others.  An EQ will allow you to turn down just those frequencies without having to turn down the whole volume.

The kids talent show went well by the way.  We didn’t have the proper microphones to amplify the drama, but the audience was small and could hear the kids fine, and fortunately I had a separate volume on the record feed so that I could turn up the mic volume on the recording without risking feedback from the main speakers. 

Your questions and suggestions are welcome, so if I wasn’t clear on anything or if you have a preference on the next topic, please feel free to comment or contact me directly (my contact info is on the about page).