Equalization, or EQ, is one of the most basic, flexible and powerful tools at the recording engineer's disposal. EQ mechanisms vary, from simple hardware devices to highly complex software plug-ins. By adjusting sliders or other mechanisms associated with specific frequency ranges, the tonal character of the sound passing through the EQ can be adjusted. Used effectively, it can emphasize or deemphasize particular sounds during mixdown to give dimension to the overall sound. Because of their characteristically bright tone, brass instruments can be challenging to EQ effectively. By following a few guidelines, a variety of tonal effects can be achieved.
Set up the brass track you want to EQ to play back in your mixing platform of choice. This may be a hardware mixer attached to an ADAT recorder or a digital audio workstation (DAW) application on your computer, such as Logic or Pro Tools. Software environments are designed to mirror hardware, so the terminology will be the same. If the brass track is part of a multi-track arrangement, press or click the brass track's "Solo" button so that it plays back alone.
Insert the equalizer into the brass track's channel strip. Some hardware mixers have integrated EQs and all DAWs include at least one equalization plug-in. Use the simplest EQ available. Simpler EQs will generally have between six and ten sliders corresponding to different frequency bands across the range audible to the human ear. Bass frequencies are on the left, high frequencies are on the left.
Play back the brass track once without EQ. Close your eyes and listen carefully. Decide what kind of treatment the track requires. Depending on how it was recorded, brass will often be too bright (or "present), too dull (or "dark") or a combination thereof. Keep in mind the role you intend the brass track to play in the overall mix. A certain degree of presence is necessary for a solo piece, but can overwhelm a track in which the brass is meant to play a background role. Take notes on the tonal characteristics of the sound. These will act as your guide when equalizing. Rewind the track when finished.
Increase the 200-450Hz range to give the brass track a fuller, or "warmer," sound. The human ear can hear frequencies between approximately 30hz and 20kHz, so the 200-40Hz range is fairly close to the middle of the audible range. The middle frequencies of the brass sound will be emphasized at the expense of the higher frequencies, mellowing and warming the sound. This is particularly appropriate for background brass. Lowering these frequencies will make the tone more distant while emphasizing the higher frequencies, resulting in a nasal tone.
Increase frequencies between approximately 1 and 5kHz to brighten the tone. These frequencies are to the left of the middle of the audible range. Boosting them will increase the higher-end frequencies of the sound, giving the tone more of an edge. Lowering these frequencies will make the tone darker, withdrawing it somewhat from the overall mix. Increasing there frequencies is appropriate for many solo brass scenarios and also for creating a more aggressive sound, as in ska music.
Increase the 5.5-8kHz range to give the brass tone a raspy, high-frequency sound. This will boost the brass sound above any other tracks in the mix, without giving it the presence and immediacy of a solo track. This is particularly appropriate in big band and jazz recording, when the engineer wants to bring out a brass track that has been buried in the overall mix without making it the center of attention. Lower this frequency range to cut down on excessive raspiness or shrillness.
Experiment with different settings. Mixing, of which equalization is an important element, is as much a creative process as it is technical. While the general rule of thumb that "less is more" when it comes to equalization generally applies, it is a powerful tool for crafting a unique sound. If it sounds good to you, it's the right tone.
As a matter of standard practice, cut all frequencies below approximately 50 or 60Hz. Sound information below this level will most likely just muddy the mix. Exceptions should be made for recordings of very deep brass instruments, such as tuba or bass trombone.