The ART of EQ

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ill o.g.
Battle Points: 3
The "art" of EQ
by Aaron Trumm

EQ can be used in a variety of situations, from live sound to recording to tape to mixing down. Mainly, it should be used to enhance signals that have some problem. The golden rule of EQ is less is more. If something seems fine without it, I avoid EQing it at all. Then, if I do use it, I try to remain subtle. My personal golden rule is nearly never EQ signals going to tape (as in a multitracking situation). I always try to get the original sound on tape, then I can mess with it later. Putting EQ (or any other effect) on tape usually just leads to trouble. The other rule (the silver rule ) is cutting is almost always better than boosting, especially when fixing problems. For example if a guitar sounds too thin, first try cutting high frequencies and boosting the gain a bit, instead of boosting the lows. The more clutter you can remove from a mix, the better. A better example is I very often cut a bit of high away from hats. Another example is, many times you may not hear something well in a mix...You might try cutting some frequencies in a different track that seems to be interfering, rather than boosting in the track you want to bring out. With these basic rules in mind, I'll tell you my rules when I enter a mixdown session:
3. Rule Of Opposites: Usually, tracks with high sounds, (a high guitar, hats) need cutting in high frequencies and boosting in lower, and vice-versa. This is really only a starting guide, not a rule. Also, sounds that interfere with eachother can be separated in a mix by EQing them in opposite directions.
4. Bass usually needs a boost in the mid range somewhere and sometimes the high. This way it can cut through and be heard on smaller speakers.
5. Kick drums usually need that same mid and/or high boost on a subtle level so they too can cut through on smaller speakers. For hip-hop, kick needs a low end boost, but NOT TOO MUCH.
6. Snare drums always sound warmer with a boost in the low-mid range and some cut of the highs. An annoying CRACK can be softened with this high cut. Sometimes I boost the lows in snares to make them even fatter. But it really depends on the snare sound. The rule of opposites usually applies here. Snare sounds that were thin to begin with I usually warm up a bit, and heafty snare sounds I might thin out a bit.
7. Hats almost never need any EQ if they're recorded clean. Usually an EQing for my hat tracks is to cut highs to get rid of an annoying hiss.
8. Guitars are simaler to snares for me. A thin original guitar might need boosting in mids and lows (depending on what the desired sound is, and what else is present in the mix) or a heafty guitar might need to be thinned out a little by cutting lows and low-mids.
9. Vocals usually like to have a boost in the mids or high-mids, but it depends on the voice. Vocals nearly always get lost amongst guitars...a good way to deal with this is the rule of opposites. Boost mids in the vocals and cut them in the guitar, or something similar. Vocals can also have annoying hiss or sibilance, and sometimes cutting high frequencies can help that.
10. Strings, and more specifically good string patches from a synth, usually need little EQ. If they are merely a support player, I may thin them out a tiny bit, or if they are meant to be present, I may thicken them in the mids a little (or sometimes the opposite...this stuff is highly subjective). But they usually work well left alone. Really clean piano or keyboard synth patches are the same way.
11. I like to leave reverb returns alone, but if the reverb becomes annoying and noisy, cutting some high can soften it up a bit...same with strings.
12. Extreme EQ setting create sounds of their own. Experiment. But for a non-novel track, be subtle.
13. AC hum from a track can almost always be fixed by cutting 60 Hz all the way off. (Sometimes this can take away from bass or kick sounds, but I believe that most frequencies audible in a song are above 60 Hz).
14. Play with EQ settings thoroughly to find appropriate settings.
15. I don't mix horns too often, but when I do, I like to leave them alone. Clean horn tracks usually seem fine to me.
16. NEVER EVER EVER force yourself to EQ a track that sounds fine, just because you think you should use the full capabilities of the studio. NEVER NEVER NEVER!
If anyone out there has rules they use for their mixes, especially for instruments I don't mention or use much, send 'em along.



A Basic Guide for EQing
by Devin Devore

Some History
Dating as far back as the 1930's, the equaliser is the oldest and probably the most extensively used signal processing device availible to the recording or sound reinforcement engineer. Today there are many types of equilisers availible, and these vary greatly in sophistication, from the simple bass and treble tone control of the fifties to advanced equipment like the modern multi-band graphic equaliser and the more complex parametric types. Basically, an equaliser consists of a number of electronic filters which allow frequency response of a sound system or signal chain to be altered. Over the past half century, equalisers design has grown increasingly sophisticated. Designs began with the basic 'shelving filter', but have since evolved to meet the requirements of today's audio industry.
Understanding EQ and its Effects on Signals
There are two areas of equalisation that I want to cover. Those two areas are vocals and music. I'd like to discuss the different effects of frequencies within audio signals. What do certain frequencies do for sound and how we understand those sounds. Why are some sound harsh? Why do things sound muddy? Why can't I understand the vocals? I'll try and answer all of these question and hopefully bring some light to the voo-doo world of EQ.
Vocals
Roughly speaking, the speech spectrum may be divided into three main frequency bands corresponding to the speech components known as fundamentals, vowels, and consonants.
Speech fundamentals occur over a fairly limited range between about 125Hz and 250Hz. The fundamental region is important in that it allows us to tell who is speaking, and its clear transmission is therefore essential as far as voice quality is concerned.
Vowels essentially contain the maximum energy and power of the voice, occurring over the range of 350Hz to 2000Hz. Consonants occuring over the range of 1500Hz to 4000Hz contain little energy but are essential to intelligibility.
For example, the frequency range from 63 to 500Hz carries 60% of the power of the voice and yet contributes only 5% to the intelligibility. The 500Hz to 1KHz region produces 35% of the intelligibility, while the range from 1 to 8KHz produces just 5% of the power but 60% of the intelligibilty.
By rolling off the low frequencies and accentuating the range from 1 to 5KHz, the intelligibility and clarity can be improved.
Here are some of the effect EQ can have in regards to intelligibilty. Boosting the low frequencies from 100 to 250Hz makes a vocal boomy or chesty. A cut in the 150 to 500Hz area will make it boxy, hollow, or tubelike. Dips around 500 to 1Khz produce hardness, while peaks about 1 and 3Khz produce a hard metallic nasal quality. Dips around 2 to 5KHz reduce intelligibilty and make vocals woolly and lifeless. Peaks in the 4 to 10KHz produce sibilance and a gritty quality.
Effects of Equalisation on Vocals
For the best control over any audio signal, fully parametric EQ's are the best way to go.
Σφάλμα! Δεν έχει οριστεί σελιδοδείκτης.80 to 125 160 to 250 315 to 500 Sense of power in some outstanding bass singers. Voice fundamentals Important to voice quality
630 to 1K Important for a natural sound. Too much boost in the 315 to 1K range produces a honky, telephone-like quality.
1.25 to 4K 5 to 8K Accentuation of vocals Important to vocal intelligibility. Too much boost between 2 and 4KHz can mask certain vocal sounds such as 'm', 'b', 'v'. Too much boost between 1 and 4KHz can produce 'listening fatigue'. Vocals can be highlighted at the 3KHz area and at the same time dipping the instruments at the same frequency. Accentuation of vocals.
The range from 1.25 to 8K governs the clarity of vocals.
5 to16K Too much in this area can cause sibilance.



Instruments

Miking instruments is an art ... and equalisers 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 miking. An equaliser 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 equalisers to strighten 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.
Σφάλμα! Δεν έχει οριστεί σελιδοδείκτης.31Hz to 50Hz These frequencies give music a sense of power. If over emphasised 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 fundemental 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 clearity of bass is defined a lot at 800Hz. Too much low end can mask the clearity 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 clearity. Think of sounds in a linear fashion, like on a graph. If there is too much bass and no clearity, you would see a bump in the low end masking the top end. The use of EQ can fix those abnormalities.
Guitar/piano/ etc.:
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
Equalisers are one of the most over looked and mis-used pieces of gear in the audio industry. By understanding equalisers 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. Equalisers are also a lot more effective taking away things in the signal than replacing what was never there.



Reverb

Reverb is an important studio tool. It can be used to add realistic ambience to a sound that was recorded in a dead, dry room, or to electronic or synth sounds. About everything we hear has some reverb to it, so when we hear an untreated sound, it sounds uncomfortable, and unnatural.
Back in the sixties and seventies before there was digital reverb, studios used plate reverb. They would hang a thin piece of metal inside some frame work, and vibrate it using a voice-coil assembly. Then they would mic the metal plate with contact mics and feed that back into the mixer. The only problem with this method was that it sounded metallic and bright. After so many years of hearing this, people were used to it, and the new digital reverbs sounded strange to them. Now, digital reverb units repeat little fragments of the sound wave thousands of times to recreate reverberation. Most reverb units have hall sounds, room sounds, and, of course, plate sounds which are great for drums.
Basic Rules for Using Reverb
The effect sounds the best when used in sparingly. Don't swamp tracks in it. Use the least possible to get the desired effect. The best engineers know when they have used too much.
Sounds with a lot of bass, such as the kick drum or bass guitar are best left with little or no reverb. If you do use it, keep it short and bright, or cut the low frequencies on the reverb return. Otherwise you'll have a big mess before you know it.
Obviously the more reverb you use, the farther away a sound will seem. This can be used to push certain things back in the mix such as backing vocals, but once again, don't load it on.
Many times your effects unit will allow you to use many different types of reverb in one mix. Theres nothing wrong with using a couple of different reverb styles all within the same mix, it will just sound more interesting to the ear.
Useful Settings
Drums
Style:
Bright Plates, nonlinear
Length:
Between 1.1 and 2.5 seconds
Pre-delay:
Around 20 milliseconds
Vocals
Style:
Plate or short hall
Length:
Between 2 and 3 seconds
Pre-delay:
Between 20 and 60 milliseconds
Piano
Style
Hall or concert hall
Length:
Between 2 and 4 seconds
Pre-delay:
Between 5 and 50 milliseconds
Electric Guitar
Style:
Room or Plate
Length:
Between 1.5 and 3.5 seconds
Pre-delay
Between 20 and 50 milliseconds
Strings
Style
Plate or Bright hall
Length:
Between 1 and 2.5 seconds
Pre-delay
Between 20 and 80 milliseconds
 

2_nice

ILLIEN
ill o.g.
a good common technique not here for natural sounding eq which works on the principal of a sound double it's frequency being an octave higher is feathered e.q where if you're cutting at say 400hz 1.5 db with a fairly high q you will also cut say 0.7 db at 200hz and depending on what you're going for maybe 0.7 or less at 800hz this is then cutting the exact harmonics of the exact sound you're cutting. a pitch frequency guide can be good while eqing and you can e.q to work with the key you're in (it;s more important though cutting or boosting in the right range
 

light

Producer
ill o.g.
the greatest thing ive read yet... thanks
 
ill o.g.
The net is full of all of these technical guides and what have you...
Personally ive been starting to come to the conclusion that all those documents with little frequency tables kind of suck. It makes you sit there and look at what you are doing rather than listen. So you will pop open your eq and use the guide and say oh ill boost this kick at 100 hz because the guide says thats good (or whatever). This is bad, I think the very first golden rule of eqing should be USE YOUR EARS....

Not all kicks, snares, hihats, vocals or whatever sound the same...

make music like a musician, not a scientist....

just my two cents

peace

The things in these type of articles that are good sound advice are things like cut dont boost, try to get frequencies in their own place etc...
 
ill o.g.
LocZ said:
you r a 100% right in my opinion dys but they r good for understanding what your goal is and where and what to fiddle wit till you get that result your ears are listen for but ya right if they tell you 1 thing don't just do it cuz they say an it dont sound good but there guidance in the sense as to what they tellin you to do is help ful cuz my mixes sound hell alot betta since i 've read these tips

True that, no doubt...

Peace
 

Architect

ILLIEN
ill o.g.
Battle Points: 3
Thats true, keep it simple learn how to listen FIRST! Even if you know all of the science about EQing it just won't help you a lick unless you have good ears/monitoring and judgement about how an instrument should sound in comparison to other instruments in the mix.

Basically if you need to EQ it's because you want to FIX something or alter the sound altogether of an instrument so in the latter case your using EQ as an effect.


One thing that has helped me out more than anything else in music production is actually spending time LISTENING critically to my mixes, understanding the sound of each instrument and knowing how to bring out in the song what I'm listening to in my head. This goes along with studying the art and/or training yourself to some degree in musicianship (piano lessons, studying the greatest musicians, etc). Just my two cents.
 

Hypnotist

Ear Manipulator
ill o.g.
AWESOME POST!!!! I know a lotta cats are gonna get some good stuff outta this. I've heard most of this, but this is the most detailed I've ever seen in terms of breaking down frequencies and what they actually do. Quite informative.

Here are some extra things that I've experienced with EQ:

WingsOfAnAngel said:
13. AC hum from a track can almost always be fixed by cutting 60 Hz all the way off. (Sometimes this can take away from bass or kick sounds, but I believe that most frequencies audible in a song are above 60 Hz).

If you only cut 60 Hz with a notch filter (using a VERY narrow bandwidth) the neighboring frequencies are somewhat left alone, and it doesn't really affect your low-end, while taking out your AC hum. While we're on this subject (I've posted about this before) before you begin, make sure all your audio equipment is plugged into the same socket, that lighting is on a different circuit, that audio cables cross your power cables perpendicularly, and you will greatly reduce ground hum or AC hum. Fluorescent lights are the WORST for hum.

WingsOfAnAngel said:
5 to16K Too much in this area can cause sibilance.

A more precise band of sibilance occurs between 7-10 kHz, depending on your microphone, and even your compression settings. I've noticed that overcompression will result in sibilance being thicker around 7kHz, while undercompressed signals will have more sibilance around 9-10 kHz. It could just be the microphones I've used. If there is too much sibilance, a "de-esser" is reliable, while only removing the esses, and not taking away from your high end of your vocals. Set the de-esser to 7-10 kHz, and adjust depending on where it's more prevalent. Set your threshold lightly, and use moderately, and it will sound natural.

WingsOfAnAngel said:
Clarity of many instruments can be improved by boosting their harmonics.

Absolutely. Any vibration will vibrate throughout its harmonics, naturally. So if you play a guitar at A 110 Hz, it will also vibrate at A 220, A 330, A 440, A 550, etc, and all the way up. If you actually cut 110 from a A 110 string, you'll begin to hear the higher octaves, slowly cutting off as they get higher. You'll hear 220 more than 330, and so on.

So what you do: If you want to bring out a lower-to-mid frequency in an instrument, then boost that frequency very moderately, and then boost its harmonics slightly as well. Sometimes you won't really hear these harmonics in the mix, but it will definitely bring it out more. And vice versa... if you want to cut a frequency, then sometimes you can find its harmonic.

WingsOfAnAngel said:
Also, knowing if its a mic character or mic placement problem.

Very true. Placing a microphone at the hole in a guitar will add body, while putting another mic on the 13th fret will get a nice midrange, along with some extra pick sounds. Being really close to a microphone (unless it's an omni-directional) will give you "proximity effect", which adds low-end tones to your voice. Phasing issues is a whole 'nuther subject, but if you don't use the "three-to-one rule", or place one micrphone three times the distance from another, you will get phasing issues, and some frequencies will be cut.


Some basic cutting/boosting techniques I've used:

When you cut or boost, start at 1dB at a time. You may look at a graphic equalizer and see an enormous dip, and you realize you have it cut 12dB. Too much! Make very moderate cuts/boosts, and LISTEN CAREFULLY.

If you don't hear what you want to cut or boost, then set your bandwidth to the smallest level for a specific frequency ("Q" must equal the largest number for the smallest bandwidth). Turn down the fader first, and solo the track (It could damage your ears or your monitors). Now raise whatever frequency you want to eliminate or boost, (all the way up, maybe 12dB) and sweep it across the nearby frequencies until you find it. This is good especially for cutting frequencies, when you want to find that annoying nasal sound, but can't pinpoint it, or you want to reduce hum or air conditioning sound, or the rumble of a truck going by, if you don't have an isolation booth.

Basically, look at your entire mix as an appointment book. Every instrument gets its own little slot. If musically composed correctly, with the right layers of harmonies and instruments, you won't need too much EQ. But with pop/rock/loud hip hop, you need to find a comfy little place in the frequency spectrum for it to sit and be itself. With a complicated mix, sometimes I draw out a diagram first, and pen in the basic slots of where I want everything to sit. This is just a rough sketch, because I'm probably going to be slightly off from where the instruments WANT to sit. Every instrument has its own sweet spot in the mix, as it also has a sweet spot for you to place a microphone in front of it to get its full potential. And within every instrument, every note has its own spot in the mix as well. You might find that you'll cut 80 Hz from your bass line, and you can barely hear the low notes. Or, you'll put a low-pass filter around 175 Hz to only contain the low-end, and all your higher bass notes will disappear. So USE IT SPARINGLY. But there is an art to it. Read up on it as much as possible, and then APPLY it to your own mixes. You'll never see what people are talking about until you USE IT.

Thanks Wings! This post was the shit.

-Hypno
 
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