How It All Pans Out

Pan is a knob you’ll find on most mixing consoles, usually the first knob right above the main volume fader. It’s function is fairly simple, it assigns that channel to go out the left or right output. Yes, that sounds a lot like the “Balance” you find on your home and car stereos, but there is a subtle difference. In fact, most boards today will have a few channels where the knob is labeled Balance (or BAL) instead of Pan. Those are the channels with stereo inputs.
When you pan an input, you are taking a single input, for example a microphone or instrument, and pushing it to either the left or right output. When you turn the balance to one direction or another, you are choosing between two different inputs, left or right from stereo inputs such as MP3 players, computers, CD players, etc.
If your mixing console doesn’t have those stereo channels and you want to run your sound system in true stereo, then you can have the same effect by using two channels, and pan your left input to the left, and the second channel with the right input to the right.

Keep in mind, the pan has no effect if you are using only a mono output where your main speakers are only connected to one output on the amp or mixer. However, even in a mono system, the balance does allow you to adjust the volume between the left and right inputs. If you turn the balance to the far right, you are muting the left input. I don’t recommend it, but if you are in a bind and need to have more channels to work with, you can plug similar instruments into the two inputs of a stereo channel and use the pan as your volume. But this will only work with mono outputs and you lose the ability to EQ the two sources individually, and can’t have separate control to the monitors (auxiliary outputs).

Look for a future post that will have some tips and application ideas regarding split track CD’s. Also, the Pan plays an important role when dealing with subgroups, which will be discussed in detail also in a future post.

Anyone need a 12 step program?

Harmony-Central.com has an article called “Mixing: The 12-Step Program” that I thought was a great resource.  It was written for studio musicians, but there’s a lot of helpful tips that apply to the live church environment as well.  It starts with a great introduction:

In theory, mixing should be easy: you just adjust the knobs until everything sounds great. But this doesn’t happen by accident. Mixing is as difficult to master as playing a musical instrument

It’s been a long time since I’ve posted, but not because I haven’t thought about it.  In fact, I’ve been composing in my head a post about how being the sound guy requires a lot of the same skills and talents as being a musician.  After all, even though you’re not playing the instruments, you make the decision as to which instruments get heard and which ones are lost in the background.  It’s nice to know someone reaffirms my opinion that learning to mix is like mastering an instrument in itself.

The Questions in your Mind

As you are mixing some instruments and vocals together, there are several different questions you can keep asking to evaluate which channels need to be modified. At the typical youth event or concert, the primary question is “Is this as loud as I can get it?” Even in my own high school years I got a thrill from being in the front row or mosh pit and see how much noise I can sustain. Hearing the actual instruments or words to the song came second to thinking I’m cool because the subwoofer was disrupting my digestion.

But as I find myself mixing worship events and caring more about hearing the words and the subtleties between different instruments, the main question I try to keep my focus on is “What can I turn down?”  It’s not that I don’t want anything to be loud, I still appreciate the quantity at times (and I’m not 30 yet).  But the most common mistake when mixing is to turn channels up when something isn’t right.  For example, the band is picking up volume and it’s hard to hear the singer, so you go and turn up the microphone volume.  But then the guitar is getting lost in the background and you turn it up.  Before you know it, your volume has increased too much for the room size or possibly distorting.

So instead, try to keep things at your target volume, and when you think the vocals or a certain instrument is being lost or drowned out…ask yourself what can be turned down to fix this mix.   That way you keep your overall volume consistent, and you can highlight the quality of the mix without faking it with quantity.

As I think about it, this principle is a main focus for a lot of audio engineering aspects, not just the house mix.  I apply the same principle when trying to use the equalizer to fix the tone of a channel or mix.  When a channel doesn’t sound right and the EQ needs to be modified, I think of which frequencies can be cut and do so, only increasing on the rare exceptions when too many cuts have already happened or there really is a need for boosting just a single frequency by a small amount.

This principle is especially important when mixing monitors and even in ears.  The biggest trap you can fall into is turning up instruments or microphones when a musician asks you to.  This is especially problematic when a single monitor speaker is shared between two or more musicians.  For example, the lead singer says they need more vocal and you turn it up, then the guitarist says he needs more.  As soon as you turn the guitar up, the vocalist again says he needs more.  Neither realize that the vocal range and guitar range are close in frequency range and are literally drowning each other out, competing for which input has more dominance in the monitor.  And you become stuck with this really loud monitor that is competing with and possibly overpowering the FOH (Front of House) speakers.

With dedicated monitors or in-ears, you can evaluate which instrument or channel is most important to the musician and make sure the mix reflects that, turning down other channels until the instrument they want is at the forefront (which 99 out of 100 times is their own instrument or vocal).  With shared monitors, you will have to communicate with the musicians to work out a compromise, or try to arrange the stage so that complimentary (instead of competing) instruments are sharing the monitor feed.  When the guitarist is asking for more volume, you can tell him or her that the monitor is as loud as you can allow it and ask if other instruments can be turned down instead.  Usually the people sharing the monitor can agree to some kind of compromise.

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).