So here is a general list of how I would EQ most things.  This is obviously going to be dependent on circumstances and particular models of instruments.  But in general, and what I do at Grace Community Church where I mix on a regualr basis: Click here for the PDF Copy: eq-by-instrument.  It was just too long and I couldn’t get the formatting correct for the blog post.

So, trying to nail down EQ ‘terms’ or ‘ranges’ is like trying to nail down jello.  But lets give it a try with some definitions but also some practical steps.

Low range:

30 – 50 Hz: Sub-woofer activation. When I want the subs to move and shake and be made known, these are the frequencies.  Boosting the kick drum, bass drum, string bass, electric bass at these frequencies makes the difference.

50 – 125 Hz: Warmth.  Acoustic guitar, cello, electric bass, vocals can have some help here.  But this range might need cuts if proximity-effect is a problem

125 – 300 Hz: Thickness.  Thickness might be a good thing for steak, but in general I find myself cutting frequencies here.  Other terms might be muddy or soupy.  Slight boosts here can help electric bass note definition, but carefully and minimally.

Low – Mid range:

300 – 700 Hz: Roundness. Rotundness. Tubby.  Generally another bad group of frequencies.  Acoustic Guitars can normally have some 400 Hz taken out.  However, this is an important range for woodwind instruments as there fundamentals are naturally not as loud in that range.  So definite boosts for woodwinds in this range are allowable.  Middle instruments (think viola and trombone) are a hard sell in this range but don’t cut too much or those instruments don’t serve their purpose of filling in the middle.

700 Hz – 1.2 kHz: Boxiness. Squareness. Nasal. Throaty.  Basically the ugliest frequencies on the face of the planet.  Cutting here for vocals and a lot of instruments can help “clean” things up.  However, taking out this frequency for electric guitars can make them too lean with no edge.  And bass guitar has harmonics that are nice here and those cool high-bass-solo notes.  I’d echo the same sentiment about “middle instruments” as I did above in this range as well.

High – Mid range

1.2 – 3.0 kHz: Attack and Presence. Boosting on this range helps with attacks on snare, kick drum, and other percussion instruments.  This range can add some brightness to vocals and woodwinds.  But the range can also add a “tinny” quality (more between 1.2 and 2 kHz).

3 - 6 kHz: Bright, Scratchy, Stringy.  Adding some 3-4 kHz on woodwinds and some vocals can increase brightness.  Or is sibilance (“s” sounds) on vocals is a problem cut between 4 – 6 kHz.  Cutting between 3-4kHz is a must for close-mic’ed high strings that are scratchy or pinched.  Cutting around 6 kHz for almost all close-mic’ed bowed instruments can reduce the string noise of the bow vibrating the string.  Watch out for the 4 kHz ice-pick-to-the-head on vocals and electric instruments (guitars, synths).  This is that top-octave-of-the-piano range that can just cause your head to explode.

High Frequency

6 – 10 kHz. Sizzle. Guitars can have a vibrant sizzle at this range (6 – 8 kHz). That could be good or bad, depending on the pickup system, mix, etc.  Cymbals and snares also sizzle in these ranges.  And other high metals instruments (e.g. chimes, triangle) can be heard here.

10 kHz and above: Air and noise.  These frequencies add a feeling of space and air to close mic’ed vocals and instruments.  They can also add that extra zing to cymbals and other percussion instruments.

Before we go further, I thought we could maybe talk a little heady philosophy of EQ.  There are those that think you don’t need any EQ, those that think only cutting is appropriate for EQ, those who think that because we can we should–in fact we must EQ!

EQ kind of reminds me of the affects of the fall.  Once sin entered the world our entire human experience is now one of fighting against its affect, and how we fight against them is different, but ultimately a losing battle without the victory of Jesus Christ.  Well similarly (kind of), once microphones and speakers and amplifiers entered the world of sound and acoustics, once sound recording and reinforcement came into the world, we are now fighting against their affects against sounds as we knew them.  And the debate is basically over what we are going to do about those affects.  Do we spend the most dollars for the best pre-amps and the best microphones and build extravagant, perfect recording studios?  Or do we use EQ?  Do we take 1 hour to place each microphone in just the right place?  Or do we use EQ?  Do we optimize our system and venues to the absolute strictest standards?  Or do we use EQ?  So, is there a Messiah to save our sounds?

Well…no. There is no ultimate victory.  There is no magic bullet.  What am I getting at?  All of sound recording and, especially so, sound reinforcement is a series of compromises.  Everything is a battle of compromises to get the best possible result we can with what we have, while many different factors fight against us simultaneously.  The name of the game is to know about the affects, the factors and the tools.  And EQ is just one of those tools, applying to some (maybe a lot) of those factors.

So EQ is the right answer to some of the problems.  EQ is the wrong answer to some of the problems.  EQ is a possible answer to quite a few of the problems.  So now for all the generalities:

1) Excessive EQ is a sign of another problem, that needs a different ’solution.’  For example, if all the EQ knobs on your sound console are pegged left or right…something else is wrong and you need to find out what.  Probable culprits are microphone placement, bad connections, improper gain structure, blown speaker components, etc. One guy I knew (who was a bit of a recording purest, but one of the best sound guys I’ve ever met) used to say that back-in-the-day any EQ beyond plus or minus 3dB was considered excesive and signs of a system or placement or other problem.

2) EQ by instruments to be natural.  Instruments, as they are built and designed, have specific resonances that project in specific ways around/from the instrument.  EQ’ing instruments by trying to negate or amplify the affects of microphone placement and microphone limitations on these projections and eccentricities is a very “natural” technique and will call for mostly “cutting” frequencies.  For example, if you need the microphone to be close to an oboe due to gain before feedback and stage noise (after all we aren’t in a studio in the live world); then you need to take out some 2-3kHz using EQ because a mic placed close to an oboe will pick up more of this frequency than the average listener in an audience would.  Or if you are trying to get that “bright” French Horn sound, you aren’t doing this, because French Horns project to the rear and are meant to be heard more diffuse and mellow (the woodwind of the Brass section). So, EQ’ing a French Horn “brightly” or “with presence” would be wrong.

3) EQ in the mix to be contemporary.  More contemporary mixes (worship bands or otherwise) have more EQ applied in order to “carve out a space” or “bring something forward” in the mix than particularly because of the instrument.  This style will lead to more EQ used both to cut and boost frequencies of an instrument as they sit in the mix.  This isn’t drastically different than #2 above because…if you think about it…a lot of “electronic” instruments in the modern worship band don’t have a “natural” sound to begin with.  Hence the adage, ‘That doesn’t sound like it does through my amp’ is often true.  Because the amp is a part of the ‘natural’ sound of the electronic instrument that the player is used to.  As a player might tweak their amp to “get” that perfect sound, so the sound guy “tweaks” with things to get the mix right.  So we notch the bass up between the kick and lead vocal, and cut some mid out of the acoustic to let the electric sit in the middle (or vica versa), etc, etc, ad nauseam.

4) Louder = More EQ needed.  This I find true from experience. To continue to make a sound or a band louder and louder, more and more EQ must be used to compensate.  The reasons vary: maybe fighting feedback means notching out more frequencies, maybe trying to get that vocal over the band means more punch in the 3-4kHz range.  Or, conversely, because of the way our ears work (look up the Fletcher-Munsen or equal-loudness curves) at louder levels our ears aren’t as sensitive to mid-range frequencies so sometimes EQ, whether dramatic cuts or boosts, are used to compensate for this change in how we “hear” the sounds.

5) The broader the range, the more challenging the EQ.  The more challenging the EQ, the broader the range.  This means that pianos, guitars, keyboards, etc. are really difficult to get right, in particular if close-mic’ing is necessary (as it always is in live sound).  Because of the broad range of these instruments and the chords that they can form EQ’ing them is challenging.  So, wider is better.  Notch filters on these instruments may solve your problem.  But in general these instruments need wider solutions.  In general vocals are like that too, mainly because we all know what vocals sound like and sharp filtering can make things sound fake.  So unless feedback is a major issue, lay off the notch filters on the vocals.  (P.S. I know the opposite argument can be made, i.e. wider EQ’s affect more and that makes things sound “fake”, but in general I haven’t found that to be the case).  Also see #1 above.

I reserve the right to change my mind, be corrected, or just generally add to this post at a later date.