Friday, September 5, 2014

EQ Part 3 of 3 (hopefully the last one for now)

So we know what physically EQ is...
We know of one way to use an EQ that may or may not be artistic
we understand the implications of objectivity and EQ decisions...

Now I would like to discuss the jelly of EQ...

Incidentally the expression "the jelly" is something I heard Quincy Jones say to describe something from the thriller album.  Apparently he was not too keen on the lengthy drum and bass intro for Billy Jean.  When he suggested to Michael Jackson that it get cut shorter, MJ responded with something like "you have to leave that in...  That's what gets the people dancing...  That's the Jelly of the song".

At any rate, what is the Jelly of EQ?  the artistic application of an EQ.

Like any good effect, the original intended use for an effect gets distorted over time, and new effects emerge.  Similar to how the EQ was used to EQ rooms, it then was taken a step further and used to alter individual tracks in a multi track recording...

With this awesome new found power comes some significantly awesome responsibility as well.
What I mean by this will be explained in a minute, but let's first examine some applications where we might want to EQ individual tracks on a multi track recording.

One major application is to avoid masking.  What is masking?  masking is when one instrument/track in you multi track has similar frequency, time, spacial queues, and timbral detail, they will both not be well defined as a result.  some good examples are listed below, but the bottom line is that when these things occur, it's usually problematic.  *One way to fix this is to EQ them differently.  Incidentally they actually sell systems that are intended to mask things.  Typically they are installed in a cube world and broadcast white or pink noise to purposely mask other people talking and other office noises...  Mostly they are installed to be a background noise generator, which is odd because while you become acutely aware of their effect, you usually aren't all that aware of the masking system itself.

Like the graphic suggests, it cancels unwanted noise, but it also can cancel wanted noise in the case of multi track recording.

Another artistic application is to increase/decrease certain specific frequencies.  For instance, a great application for this might be a voice.  A ton of voices sound just that little bit better with a boost in the 1k range. A similar view is that a ton of drums will sound just that little bit better with a cut in the 200 range.  if you have access to a multi track recorder, and a few tracks, I would suggest that you try this*.  Don't be afraid to overdo it just to hear the effect.  But that's where we run into some interesting side effects..

There are two major things that happen here that are interesting.

The first is that when you increase amplitude of specific frequencies, you aren't just altering that one thing...  You are altering things around it.  By that I don't mean you are affecting frequencies around 1k as well, but more that you are affecting how you perceive the 1k range of a snare drum for instance.  I would bet that tons of us make some sort of EQ decisions in a vacuum (making eq changes when the source material is being solo'd or the only active track playing)...  While there are plenty of folks who could do this without a problem, I would imagine that most of us are not those people.  More likely what we should be doing is evaluating this not just in a vacuum but then also within the framework of the song itself.  At the same time

The second is that when you decrease amplitude of specific frequencies, you aren't just altering that one thing...  You are altering things around it.  But instead of masking things, you are creating holes for stuff to live in.  So let's take that 200 Hz example with the drums.  If you did happen to take that 200 Hz out of the drums (let's assume by 12dB for now, which is extreme), you now have other stuff that could appear to be louder because they are no longer being masked by that particular frequency.  In this case, what else is in the 200 Hz Range?  TONS of stuff...  For instance, in a standard rock ensemble, guitars are in the 200 Hz range...  Vocals are in the 200 Hz range, all sorts of brass, woodwinds, and other "classical type" instruments (god I hate that designation, but you get the idea).  So in reality there is a TON of stuff that exists in the 200 Hz range, so getting rid of some tub of a drum sound to help create a hole where other stuff might be is a good thing...

A third thing can happen when you use EQ...  That is you can abuse it.
With this awesome power of changing frequency responses of tracks/instruments on the track of the muti track session we are working on comes the idea that if you turn stuff up too much you can end up with a frequency bulge...  Frequency bulges occur when you emphasize a set of frequencies across several instruments.  I suppose it's possible for there to be a frequency hole as well, but we as humans aren't normally perceptive of such things unless it is very obvious.  By way of example, almost everything to me sounds better with a 1k little boost on it (maybe a little 4k, as that is my favorite frequency).  But the point is that if you boost 1k even just a little bit on all the tracks, and then you add it up, and listen to it, you end up with a nasty bulge at 1k.  It's not normally a good thing.

For anybody who has used EQ who also has had control of the tracking of the basic sessions, or really any tracking sessions-
stop for a moment and consider what we are actually doing when we EQ tracks.

What are we actually doing?  we are effectively changing the frequency response of the track itself.  The idea is to play it back altered by this EQ effect.  Well this is an interesting thing because what we are doing artistically is altering formants...  What the deuce is a Formant?  A Formant is defined quite nicely as:

A characteristic RESONANCE region. A musical instrument may have several formant regions dictated by the shape and resonance properties of the instrument. The human voice also has formant regions determined by the size and shape of the nasal, oral and pharyngeal cavities (i.e. the vocal tract), which permit the production of differentVOWELs and voiced CONSONANTs.
Formant regions are not directly related to the PITCH of the FUNDAMENTAL frequency and may remain more or less constant as the fundamental changes. If the fundamental is well below or low in the formant range, the quality of the sound is rich, but if the fundamental is above the formant regions the sound is thin and in the case of vowels may make them impossible to produce accurately - the reason singers often seem to have poor diction on the high notes.

This might sound an awful like an EQ for an instrument.  if you really distill it, that's exactly what it is (sort of).  What it really is is frequency bulges that make the sounds sound like the sound.  That's why my voice sounds different than another voice.  That's why a trumpet sounds different than a french horn.  That's why an alto sax and a tenor sax sound different.  When we mess with EQ, we are creating, or taking away or altering in some way the formants of the sound.  You are fundamentally shifting (in a small way) what makes things sound like they sound like.  This is an awesome power indeed.

So why do we care about this?

Indeed a good question again.  This time it is meant for somebody in the tracking process.  I have seen this happen time and time again with my students at U Mass Lowell in the sound recording technology program.  The attitude of "fix it in the mix".  I would argue, if you did it right to begin with, you wouldn't have to fix it at all in the mix.  There is no point to recording a track with a specific microphone with it's specific frequency responses just to try to either undo that frequency response or fundamentally alter the sound with EQ.  What I would say (really beg my students, but others I would just say this to) is a good rule of thumb...

If you feel like you have to reach for an EQ while you are tracking to "fix it", you aren't recording it right...  Use a different microphone, move the microphone, do something, but reaching for an EQ and all it's awesomeness should be avoided until truly needed, then rather than fixing things, you can apply artistically to help the artist achieve their goals.

Let me know your thoughts on Artistic EQ use, and *if you would like to hear some examples of sounds like I mentioned above...

Until Next time...
Hopefully this is it for EQ for now.

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