The Q in EQ
We all have a little bit of experience with EQ even if you've
never recorded before. Everyone has tweaked the Bass and
Treble controls on their own home or car stereo. EQ seems
pretty basic when you only have two controls, but some people
get a little overwhelmed when faced with the EQ in their
recording software. One of the problems is a lack of documentation
on EQ. It really is pretty simple if you understand the
different types of EQ and their controls.
There are two main types of EQ: shelved EQ, and parametric
EQ. Shelved EQ usually gives you fewer controls, but easier
adjustments. The bass and treble EQ in most stereos is a
form of shelved EQ. Basically, you have a few different
set frequencies that you can boost or cut. You can have
a bass EQ "shelved" at 150 Hz, and a treble EQ
shelved at 6 kHz. Or, these two controls could be shelved
at different frequencies. A 15 band EQ has 15 different
"shelved" frequencies that you can boost or cut.
The frequencies that these are "shelved" at can
vary depending on the manufacturer of the EQ, or the software
plugin that you are using. The controls are much simpler,
because you merely boost or cut these frequencies.
Although shelved EQ can be simpler, parametric EQ gives
you much greater control and tonal shaping. It also tends
to sound more natural, because you aren't just adjusting
one frequency. The problem most people have using parametric
EQ is when they just start adjusting knobs without understanding
how they work. Parametric EQ gives you sweepable control
of the frequencies. This means that you can choose whichever
frequencies you want to adjust. This is not the end of the
controls available in parametric EQ, however. One of the
most often overlooked adjustments is the "Q".
The "Q" in parametric is what sets it apart from
shelved EQ. The Q allows you to adjust how many frequencies
around the one frequency you want to adjust. If you think
of a loose Q as a hill when you boost, or a valley when
you cut, this helps. As you tighten the Q, the hill becomes
a peak. This allows you to tighten the Q so you are mostly
adjusting the one frequency you select, and adjusting the
frequencies directly around it slightly. As you loosen the
Q, you are affecting a wider frequency range. The problem
most people have is when they don't adjust the Q and they
are adjusting too many frequencies at one time. If you don't
adjust the Q you can't zero in on specific frequencies to
boost or cut them.
A loose Q is very helpful if you want to brighten the overall
sound of the cymbals in a drum mix. Or, if you want to add
an airiness to a vocal track, by boosting the high frequencies
with a loose Q. A tight Q is helpful if you want to cut
an annoying ringing sound on a snare drum track, which is
usually in the high mid range frequencies around 1 to 2
kHz. It could also be used to get rid of a nasal sound on
a vocal track, by cutting around the same frequency.
If you want to get rid of a certain frequency but are not
certain which frequency is the offender, there is a simple
way. Tighten the Q and boost the gain, while sweeping the
frequency selector until you really find the sound annoying.
Then, simply cut this frequency with the gain selector.
Now you have found the offending frequency, and cut it.
This is one of the great things about parametric EQs. They
allow you to zero in on any frequency and boost or cut it.
With a little practice and these newfound techniques, EQ
should be a lot less overwhelming and a lot more usable.
Whatever you adjust on your parametric EQ, remember that
Q can be a great thing if adjusted properly. Don't be afraid
to use it and see what it does to your EQ!
