Equalization Of Instruments

Equalization Of Instruments

Instruments

Mic'ing instruments is an art ... and equalizers can often times be used to help an engineer get the sound he is looking for. Many instruments have complex sounds with radiating patterns that make it almost impossible to capture when close mic'ing. An equalizer can compensate for these imbalances by accenting some frequencies and rolling off others. The goal is to capture the sounds as natural as possible and use equalizers to straighten out any non-linear qualities to the tones.

Clarity of many instruments can be improved by boosting their harmonics. In fact, the ear in many cases actually fills in hard-to-hear fundamental notes of sounds, provided the harmonics are clear. Drums are one instrument that can be effectively lifted and cleaned up simply by rolling off the bass giving way to more harmonic tones.

Here are a few ideas on what different frequencies do to sounds and their effects on our ears.

31Hz to 50Hz	These frequencies give music a sense of power. If over emphasized they can make things muddy and dull. Will also cloudy up some harmonic content.
80Hz to 125Hz	Too much in this area produces excessive 'boom'.
160Hz to 250Hz	This is the problem area of a lot of mixes. To much of this area can take away from the power of a mix but is still needed for warmth. 160Hz is a pet-peeve frequency of mine. Also, the fundamental of bass guitar and other bass instruments sit here.
300Hz to 500Hz	Fundamentals of string and percussion instruments.
400Hz to 1K	Fundamentals and harmonics of strings, keyboards and percussion. This is probably the most important area when trying to control or shape to a natural sound. The 'voice' of an instrument is in the mids. To much in this area can make instruments sound horn-like.
800Hz to 4K	This is a good range to accentuate instruments or warm them up. Too much in this area can produce 'listening fatigue'. Boosts in the 1K to 2K range can make instruments sound tinny.
4K to 10K	Accentuation of percussion, cymbals, and snare drum. Playing with 5K makes the overall sound more distant or transparent.
8K to 20K	This area is often what defines the quality of a recording or mix. This area can also help define depth and 'air' to mix. Too much can take away from the natural sense of a mix by becoming shrill and brittle.

Here are a few other pin point frequencies to start with for different instruments. In a live sound situation, I might event pre set the console's eq to these frequencies to help save time once the sound check is under way. These aren't the answers to everything... just a place to start at.

Kick Drum:

Besides the usual cuts in the 200Hz to 400 area, some tighter Q cuts at 160Hz, 800Hz and 1.3k may help. The point of these cuts makes for space for the fundamental tones of a bass guitar or stand up. I have also found a high pass filter at 50Hz will help tighten up the kick along with giving your compressor a signal it can deal with musically. 5K to 7K for snap.

Snare Drum:

The snare drum is an instrument that can really be clouded by having too much low end. Frequencies under about 150Hz are really un-usable for modern mixing styles. I would suggest a high pass filter in this case. Most snares are out front enough so a few cuts might be all that is needed. I like to start with 400Hz, 800Hz, and some 1.3K. This are just frequencies to play with. Doesn't mean you will use all. If the snare is too transparent in the mix but I like the level it is at, a cut at 5K can give it a little more distance and that might mean a little boost at 10K to brighten it up.

High Hats:

High hats have very little low end information. I high pass at 200Hz can clean up a lot of un-usable mud in regards to mic bleed. The mid tones are the most important to a high hat. This will mean the 400Hz to 1K area but I've found the 600Hz to 800Hz area to be the most effective. To brighten up high hats, a shelving filter at 12.5K does nicely.

Toms and Floor Toms:

Again, the focus here is control. Most toms could use a cut in the 300Hz to 800Hz area. And there is nothing real usable under 100Hz for a tom... unless you are going for a special effect. Too much low end cloud up harmonics and the natural tones of the instrument. Think color not big low end.

Over Heads:

In my opinion, drum over heads are the most important mics on a drum kit. They are the ones that really define the sound of the drums. That also give the kit some ambience and space. These mics usually need a cut in the 400Hz area and can use a good rolling off at about 150Hz. Again, they are not used for power.... these mics 'are' the color of your drum sound. Roll off anything that will mask harmonic content or make your drums sound dull. Cuts at 800Hz can bring more focus to these mics and a little boost of a shelving filter at 12.5K can bring some air to the tones as well.

Bass Guitar:

Bass guitar puts out all the frequencies that you really don't want on every other instrument. The clarity of bass is defined a lot at 800Hz. Too much low end can mask the clarity of a bass line. I've heard other say that the best way to shape the bass tone is to roll off everything below 150Hz, mold the mids into the tone you are looking for, then slowly roll the low end back in until the power and body is there you are looking for. If the bass isn't defined enough, there is probably too much low end and not enough mid range clarity. Think of sounds in a linear fashion, like on a graph. If there is too much bass and no clarity, you would see a bump in the low end masking the top end. The use of EQ can fix those abnormalities.

Guitar/Piano/Others:

These instruments all have fundamentals in the mid range. Rolling off low end that is not needed or usable is a good idea. Even if you feel you can't really hear the low end, it still is doing something to the mix. Low end on these instruments give what I call support. The tone is in the mids. 400Hz and 800Hz are usually a point of interest as are the upper mids or 1K to 5K. Anything above that just adds brightness. Remember to look at perspective though. Is a kick brighter than a vocal? Is a piano bright than a vocal? Is a cymbal brighter than a vocal?

In Closing

Equalizers are one of the most over looked and mis-used pieces of gear in the audio industry. By understanding equalizers better, an engineer can control and get the results he or she is looking for. The key to EQ'ing is knowing how to get the results you are looking for. Also, knowing if its a mic character or mic placement problem. EQ can't fix everything. It can only change what signal its working with. Equalizers are also a lot more effective taking away things in the signal than replacing what was never there.

FREQUENCY:

USES:

50Hz

1. Increase to add more fullness to lowest frequency instruments like foot, toms, and the bass.

2. Reduce to decrease the "boom" of the bass and will increase overtones and the recognition of bass line in the mix. This is most often used on loud bass lines like rock.

100Hz

1. Increase to add a harder bass sound to lowest frequency instruments.

2. Increase to add fullness to guitars, snare.

3. Increase to add warmth to piano and horns.

4. Reduce to remove boom on guitars & increase clarity.

200Hz

1. Increase to add fullness to vocals.

2. Increase to add fullness to snare and guitar ( harder sound ).

3. Reduce to decrease muddiness of vocals or mid-range instruments.

4. Reduce to decrease gong sound of cymbals.

400Hz

1. Increase to add clarity to bass lines especially when speakers are at low volume.

2. Reduce to decrease "cardboard" sound of lower drums (foot and toms).

3. Reduce to decrease ambiance on cymbals.

800Hz

1. Increase for clarity and "punch" of bass.

2. Reduce to remove "cheap" sound of guitars.

1.5KHz

1. Increase for "clarity" and "pluck" of bass.

2. Reduce to remove dullness of guitars.

3KHz

1. Increase for more "pluck" of bass.

2. Increase for more attack of electric / acoustic guitar.

3. Increase for more attack on low piano parts.

4. Increase for more clarity / hardness on voice.

5. Reduce to increase breathy, soft sound on background vocals.

6. Reduce to disguise out-of-tune vocals / guitars.

5KHz

1. Increase for vocal presence.

2. Increase low frequency drum attack ( foot / toms).

3. Increase for more "finger sound" on bass.

4. Increase attack of piano, acoustic guitar and brightness on guitars (especially rock guitars).

5. Reduce to make background parts more distant.

6. Reduce to soften "thin" guitar.

7KHz

1. Increase to add attack on low frequency drums ( more metallic sound ).

2. Increase to add attack to percussion instruments.

3. Increase on dull singer.

4. Increase for more "finger sound" on acoustic bass.

5. Reduce to decrease "s" sound on singers.

6. Increase to add sharpness to synthesizers, rock guitars, acoustic guitar and piano.

10KHz

1. Increase to brighten vocals.

2. Increase for "light brightness" in acoustic guitar and piano.

3. Increase for hardness on cymbals.

4. Reduce to decrease "s" sound on singers.

15KHz

1. Increase to brighten vocals (breath sound).

2. Increase to brighten cymbals, string instruments and flutes.

3. Increase to make sampled synthesizer sound more real.

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