Miking Orchestral Instruments for Worship, Part 2

In part 1, we talked about the general principles of getting good sound from orchestral instruments. As I explained, the keys to good sound include strong rapport with the musicians, good communication skills, and a grasp of the pros and cons of miking up close versus at a distance. In this part, we’ll discuss some different mic classifications and talk about some specific miking techniques for numerous instruments.

MICROPHONE TYPES

Since we’ll be throwing around a bunch of microphone terminology here, now’s a good time to introduce some of the basic concepts. In live sound we use principally two types of microphones: dynamic and condenser. A dynamic microphone is typically more rugged and less prone to feedback, although it is also less sensitive to detail. A condenser microphone, on the other hand, will provide more detail at the expense of increased risk of feedback and possible additional pick up of unwanted sounds. In other words, the increased detail of a condenser microphone can bring both good and bad results depending on the situation.

Microphones are also defined by their sensitivity to sounds in a particular direction. Omnidirectional microphones pick up sound from all directions, which is often unwanted in live sound situations. They are generally more accurate and neutral, though, and they are less sensitive to handling noise, so there are plenty of great applications for them live. Unidirectional microphones pick up in principally one direction. They include cardioid, super-cardioid and hyper-cardioid (the latter are more tightly focused). Bi-directional (also known as figure-8) picks up both in front and in back, but not on the sides.
Because you’re most likely to be making a choice between omni and uni directional in most live sound cases, here’s a comparison:

Omnidirectional
- Pick up sounds from every direction
- More neutral and accurate
- Low handling noise
- More prone to feedback in many situations
- No proximity effect

Unidirectional
- Pick up sounds from a limited “field of view”
- Less accurate and neutral as a result of the physical characteristics necessary to make it directional
- Sometimes significant handling noise
- Less prone to feedback in many situations
- Exhibit proximity effect (increased low frequency response at close distances) which may or may not be desired

Of the above classifications, unidirectional dynamic microphones are the most common in live sound because they offer the most control over what gets amplified and what doesn’t.  However, many orchestral instruments sound much better when miked with a unidirectional or omnidirectional condenser.

WHERE DOES THE SOUND COME FROM?

I can’t count the number of times I’ve heard someone tell me “the sound comes from here”. While it is true that there may be one or more primary places that resonate, the entire instrument is a part of the sound. Often, just sticking the mic at the big opening (where you might assume all of the sound comes from) will not yield the best results.

REEDS

On that note, we’ll start with the reed instruments. Your typical reed instrument (clarinet, oboe, saxophone) will include a bell, from which some of the sound emanates, and a series of tone holes along the body that are fingered to set the pitch. While most people instinctively place a microphone right at the bell, this usually results in a very harsh sound. A great deal of the character comes from the tone holes themselves. So how do you mic a clarinet, for example? Make sure to get both the timbre of the bell and of the tone holes! You could do this with two microphones for more control at the console, but most people don’t have that luxury. A single microphone in front of the bell but off to the side, where it also catches the tone holes, can do quite nicely. Adjust to taste.  For a close-miked (direct, single instrument) sound, you’ll want to be perhaps six inches away with a unidirectional condenser or dynamic. You can certainly pick up two instruments with one mic if you move it back a bit and place it between them.

FLUTES

I am probably asked about miking a flute more frequently than any other instrument. Luckily, it is very simple to mic in most situations. Usually, you will want a condenser mic somewhere near the mouth. I find it easiest to come over the left shoulder in most situations. Try getting within a couple of inches for a jazz-style “breathy” sound, or a foot or two away for a more “round”, smooth tone. Be careful, though, if you decide to get close. There will be a lot of air movement, which microphones don’t like! For really close miking, you will need a strong windscreen, a variable-D microphone, and/or very careful mic placement. You might also try directly attaching a miniature omnidirectional condenser mic (as in a lavaliere mic) to the flute body with something elastic, as long as it’s out of the path of air. To get a pair of flutes with one mic, try getting up above the shoulders about a foot or two from each flute.

STRINGS

String instruments resonate in three primary ways: 1) the strings; 2) the air inside; and 3) the wood. The complex interaction of all three is what makes a particular violin sound the way it does. Try an experiment. Hook up a mic and listen to it in headphones. While a string player is playing, move the mic all over the instrument. Pay particular attention to the difference in timbre you get when you stick the mic at the f-hole versus where the bow meets the strings. Which sound do you like better? It is likely to be a function of the musical genre, density/difficulty of your mix, room acoustics, sound system quality, and musician skill. You will notice that you can get a range of sounds just by moving the mic an inch or two. The f-hole will give you rich body; the bow/string interaction will give you presence. Try a small condenser aimed wherever it sounds best to you or a clip-on miniature omnidirectional condenser attached to the bridge.

BRASS

The brass instruments, such as trumpet, trombone, and tuba, do not need to be miked up closely in many situations. As you may have noticed, they are capable of getting pretty loud (oh, really?). In fact, at my church, they are mainly miked up for the recording, but the house mix rarely uses those mics.
You can often get away with capturing an entire brass section with one or two mics a few feet away. That will get a very natural sound, and for that scenario, I recommend unidirectional condensers. This would be a suitable technique for light amplification (to add presence) or for a recording. If you need to close mic somebody for a solo, or if you need to do a lot of amplification, a unidirectional dynamic anywhere from an inch to a foot or so in the front of the bell tends to work pretty well. It is also easy to get a pair of trumpets or ‘bones with one mic a foot or two in front of both. The reason for switching to a dynamic when close is twofold: 1) the high volume from many brass instruments can overload some condenser microphones, and 2) many people prefer the more mellow sound of a dynamic on brass when close-miked, since the instruments are already very bright sounding.

FINAL THOUGHTS

Here are some things to consider:

-   Many mistakenly believe unidirectional mics are “laser-focused” and only pick up what’s directly in  front. In reality, they can have a relatively wide “field of view”.
-   Omnidirectional mics can sound great in many live situations. Any time the mic will be very close, and there isn’t a particularly loud “neighbor” close by (such as another instrument or a monitor) an omni may be a wonderful choice.
-   Condenser mics will pick up more detail and will therefore sound more “open”, but they will just as easily pick up more of everything you don’t want, too.
-   Clip-on mics eliminate mic stands and keep the mic placement consistent. Many manufacturers make mics with special mounts for the various instruments we’ve talked about, and you can often use lavaliere mics you may already own.
-   Sound comes from all over an instrument. Experiment with mic placement until it sounds good, even if the placemen looks “wrong”.
-   If the sound you’re capturing is bad, make sure the instrument itself actually sounds good. No amount of expensive microphones or microphone technique will overcome a bad sounding instrument.
-   Study the technical specifications of your microphones (polar pattern, frequency response, etc.) to understand more about their capabilities and limitations.

There isn’t necessarily a wrong way to mic something, of course. If it sounds good, it is good, so don’t be afraid to completely ignore my advice. The most important thing is to use your ears.

[Originally printed in Church Production Magazine, May/June 2006.]