That’s right, the placement of microphones is an art. There is no one-way to do it without a trained ear. The ears of a talented engineer or producer are not only needed to select the right microphone for the job, but to place it where it works best. Finding this “sweet spot” is what great engineers are known for.

Al Schmitt has won 18 Grammy Awards, more than any other engineer or producer living today. He has worked on over 150 gold and platinum records by such artists as Henry Mancini, Steely Dan, George Benson, Toto, Natalie Cole, Quincy Jones and Diana Krall. He has worked with a wide range of artists ranging from Frank Sinatra to Bob Dylan.

Schmitt depends on mic placement for everything he records. He does not use EQ and rarely uses compression. He lets the microphones do this processing. No matter what he is recording, he starts out with a key selection of favorite microphones and adjusts them from there. He is so skilled at which microphones to use and where to place them, it now takes him little time to set up a studio session.

When he is challenged by a new or rare instrument, Schmitt asks the player how best to mic his or her instrument. These professional musicians tend to know what works best on their instrument and he uses that as a starting point. It also makes the musician a partner in the recording process and helps establish a rapport with the engineer. Most of all, Schmitt attempts to get the sound of a vocal or instrument as it sounds to his ears in the studio.

Years of experience have taught Schmitt what works and what doesn’t. It is one of the reasons he is in such high demand. He began recording mono sound and grew through the ranks. That said, he is constantly learning and trying out new microphones. He knows that no one microphone works well for everything.

Three basic types of microphones are used today for professional recording: condensers, dynamics and ribbon mics. Each has a distinctive sound and unique parameters such as diaphragm type, polar pattern and sensitivity that help determine the final sounds being recorded and how those sounds blend together in the mix.

Before mic placement, one should make sure to choose the right microphone for the job. When recording an instrument with an edgy top end — say a trumpet — use a ribbon microphone, which is more mellow. On drums, perhaps choose dynamic microphones since they can easily take the loud levels of snares. Choosing microphones from the hundreds now available is a very subjective and artistic decision made by top engineers each day.

A mic’s pickup patterns is also important in choosing the right mic for the job. Leakage can be an engineer’s friend, but in problem situations a tight directional pattern may be needed. For ribbon mics, the nulls in the figure 8 pattern can be used to balance the sound. Other times an omni microphone pattern works best on certain instruments. For close-up vocals, be careful of bass proximity effect, which can be magnified with mics that are too directional. Often omni mics work better in these situations.

Now comes finding the optimum position for the microphone. The top engineers always trust their ears and begin by listening to how the instrument sounds. They find the sweet spot for the mic and begin placement there. This is not an easy process and requires either a lot of experience or learning. It is accomplished by physically moving the microphone around what’s being recorded or swapping it with another mic to find the right sound. Never do it by sight. Move the mic and then listen. Also, don't use EQ or other electronic manipulations in this process. This is the way great recordings have always been made.

Here are some tips: When placing an omni microphone, cover one ear and listen with the other. Move around the sound source until a spot is found where the frequencies are the most balanced. Then place the mic there. For a cardioid microphone, cover one ear and cup a hand behind the other ear. Then listen. Move around the sound source until a spot is found where the frequencies are the most balanced.

For a stereo mic or stereo pair, cup the hands behind both ears. Move around the sound source until a spot is found where the frequencies are the most balanced. Stereo ribbon mics also make excellent room mics, since they capture a natural sound at distances.

One of the difficulties of mic placement is we can't quantify how much each variable in the recording process contributes to how a recording ultimately sounds. Every recording situation is unique. The player and the instrument contribute at least 50 percent to the overall sound. The room contributes another 20 percent to the overall sound, while the position of the microphone contributes another 20 percent to the overall sound. Mic placement is the acoustic EQ and is responsible for the instrument's blend in the track. Microphone choice contributes another 10 percent to the overall sound. Since every situation is different, there is no way to write a handbook on mic placement.

Learning to choose and place microphones is the number one distinction of great engineers and producers. It the reason it takes years of experience to become good at it.