Setting EQ

Destrox

Member
So I've seen a lot of good tips here about EQ and such, but never really a specific tutorial on how to do it. I probably just missed it somehow though. I never really learned how to do it and now I kinda need it. Anyone seen/have a tutorial or advice on learning how to set EQ? (I mainly need to set it for vocals, but also a bit for acoustic guitar)
 
I'll take a swing at explaining parametric EQ for ya the best I can.

I'll start with a few definition of terms
Center Frequency - center/apex of the affected frequencies you are adjusting
Q(bandwith) - how wide the adjustment is made across the frequency band, so you can adjust many or just a narrow selection of frequencies in either direction of the center frequency
Frequency Selection (sweep) - selects the frequency you are adjusting
Gain - (in application of EQ) adjusts the selected frequency based on Q and Sweep Selection in either a boost(+more of that frequency) or a cut(-less of that frequency,) commonly with max/min of 15 dB

now that you know a little more about the common terms involved in Parametric EQ, we can go on to how you use these to your advantage
Most boards based on what it seems you're going to be encountering have the highs, mids, and lows available to adjust, commonly with the mids available attached to a sweep control.
before you start "turning knobs" you have to think about what exactly the source is lacking or has too much of while you hear it going through the system.
now based on what you hear, you can use the sweep to find the "sweet spot" that you like. To find this, you can boost the gain on the sweepable frequency band, and sweep the frequency selection knob until you find the sound that fits the instrument/vocal the best allowing for clarity and intellegibility. Once you've found that "sweet spot" you can then (if needed) bring the frequency adjustment back down into perspective (rather than blasting your audience with that frequency, unless that's what you're going for:wink:)

Now if it has a troublesome frequency, apply the same thing by boosting until you find the peak of where it is at, and then cut it until it sounds desirable.

One thing I find that can increase a lot of clarity is reducing a lot of the extreme low mids and lows to get rid of some of that "mud"

Now, the highs and lows are typically shelves, so they cover typically anything above and beyond what the sweeps will cover so just adjust these up and down depending on what you hear

Now, with EQ'in you typically are inclined to boost a lot of frequencies, but by taking away frequencies you don't need you get a lot more potential for getting over feedback and having a more natural sound to your EQ job than placing random spikes where you can when you have limited control available on the board. so keep this in mind while you're setting it. Also, this frees up room in the mix for other things.

Now if its acoustic guitar, if the system sounds good playing just about anything with everything set flat, the acoustic should be relatively the same as far as EQ adjustment, just depending on the guitar only minor things should be done, given that its a good guitar.

For vocals, I've come across so many different voices on both systems good and bad, so to tell you anything particularly solid would be assuming a voice that I hear often, and isn't as likely to work for you at your venue, with the voice you're dealing with.

What I can tell you is that a lot of voices can benefit from a hi-mid boost, and possibly a lesser amount of boost on the highs, with a low cut, to get rid of a lot of mud present in those troublesome lower frequencies.

right now I've gotta go, and I really hope this has some help and clears things up for you ;D
 
So I've seen a lot of good tips here about EQ and such, but never really a specific tutorial on how to do it. I probably just missed it somehow though. I never really learned how to do it and now I kinda need it. Anyone seen/have a tutorial or advice on learning how to set EQ? (I mainly need to set it for vocals, but also a bit for acoustic guitar)

Setting an EQ is in many ways like learning to ride a bike. Somebody cannot just tell you how to ride a bike and then go ride it. You have to have an understanding of why you use an EQ, what you are trying to accomplish and prevent. You also have to train your ear. To continue the metaphor, once you learn how to balance a system, and make it sound good, the skills stay with you.

That being said, I recommend this book: Live Sound Reinforcement, by Sean Hunter Stark. This will give you a general overview of lots of things about sound, from basic accoustics to setting EQs, to impedance, and lots of other things. Then you got to just go play with it til it sounds right.

Zehink...you hit parametric EQ right on the head, but that is only part it. There are graphic EQs which are also widely used and all sorts of live sound purposes.

You can get that book lots of places. Try your local book superstore.

PM me if you need any specific help.
 
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Are you talking room EQ, feedback surpression, or channel EQ?

There's no set way how to do this. THe best way is to spend time playing around with the gear, whether it be the strip EQ, a 31-band, or a parametric. Play a CD you know very well and see how what you do affects the sound. You can only read so much in a book, the rest comes from doing.

Some things to keep in mind, it's usually better to cut, though that tends to fall by the wayside on strip EQ. Boosting can cause frequencies to become unstable and take off on you. YMMV.

Also, a good way to get ear training is to use this handy little piece. Simple Feedback Trainer. You'll be able to train yourself to what tone corresponds with which frequency. Don't be discouraged when you don't get it at first; this is one thing that takes years to get reasonably good at.

Again, this is just something you need to practice to improve (then again, most things are like that). I'm a firm believer that you learn more by doing (and failing a few times) than by reading. Definitely get the theory behind it though and it'll come in handy.

If you have any more questions, just ask. We're more than happy to help out.
 
Also, a good way to get ear training is to use this handy little piece. Simple Feedback Trainer. You'll be able to train yourself to what tone corresponds with which frequency. Don't be discouraged when you don't get it at first; this is one thing that takes years to get reasonably good at.

This software is awesome.
 
Ian already noted the issues related to what you are trying to do, another part is what tools you have in regards to both the equalizer itself and any measurement tools. How you would implement multi-band parametric EQ, or even multiple equalizers, in a DSP device using a dual channel FFT analyzer to tune a line array system is quite different in several ways from how you would probably EQ a single input using three or four band channel EQ on the board.
 
thanks man, just going off memory too lol,
that's with me trying to dumb things down to a newbie level rather than going off on a tangent.
I'm guessing parametric EQ is one of the most commonly found EQ models out there right next to the graphic, and while setting the parametric EQ, you can probably imagine a graphic's bands moving all at once when you turn the knobs, based on what is printed on the board as far as what frequencies they are affecting, and that can really help if you are trying to set it cause you can see if you're applying way too much boosting somewhere when you really should be cutting somewhere else

Another common thing I see on ppl's EQ jobs is that they turn everything up on the EQ to try and get their sound, when all this is doing is, in fact, using the EQ knobs as another volume control, with a couple of dips in weird places making for a louder, but not-so-desirable sound.

But first and formost with setting EQ, or anything else for that matter, USE YOUR EARS. that is the best advice I, or any other sound engineer/tech/operator can tell you, if you make a change based on whatever theory you have and it looks good on paper, but it doesn't sound good, then you're just cheating both yourself and the audience out of a good show.

Your ears are the best tool you have in any sound operation, and unless there's something significantly wrong with them, they will tell you more that you absolutely have to know when behind the console, than any book, forum post, or sheet of paper ever can.
 
Who here uses a real-time graphic analyzer as an aide in setting EQ, specifically for feedback elimination? We had one back in HS but I never much cared for it since I didn't really need it, but it came in handy every once in a while.
 
Who here uses a real-time graphic analyzer ...
Now I'll admit to not having mixed in a long time, but I've seen the following device(s) or similar among the paraphernalia of top artists' mixers fairly recently: Gold Line or Ivie RTAs. After all, what's a few thousand dollars compared to the nightmare of monitor feedback?:lol:
 
Thanks everyone for the tips! What's the difference between graphic and paremetric? I'm using a Yamaha LS9 so I think it has Graphic, but I don't know what the difference is.
 
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Yes, you have 6 graphics you can patch, IIRC, on the LS9 (I don't have the console in front of me, and studio editor is on my Windows partition), and parametric EQ on every output.

The graphic EQ has faders on it, each one a filter tuned to boost or cut a specific frequency, and has a specific width (the number of frequencies on either side of the peak frequency (the one that the fader is labeled as). It's called a graphic EQ because the faders on it give a rough graphical representation of the EQ curve you set.

Parametric EQ gives you much more control/parameters, thus parametric EQ. On it, for each filter, you have a knob for gain (how much/little), a knob for which frequency you want to affect, and a knob for the bandwidth of the filter, sometimes known as Q, though they're technically two different measurements of the same thing. The bandwidth is the width of the filter and determines how many frequencies on either side of the peak frequency.

Typically I use parametric EQ to tune a speaker system to the room, and use graphics to notch out the feedback, but this is by no means the only way to do it.
 
In the pro world RTAs have greatly been replaced with more advanced tools like TEF, SIM, Smaart, SysTune, etc. Ad I'm not just talking about consultants, contractor and major tours, I have seen several of these systems used by theaters and churches and have even seen some system bids for such facilities that included one or another of these analysis tools as part of the system. The biggest difference is that unlike an RTA that lets you see things in terms of only amplitude and frequency, these systems also let you look at everything in terms of time and phase. That is very important as the frequency response of a sound system is a result of phase relationships as well as amplitude relationships; signals out of phase cancel, signal in phase sum and those in between do something in between. The best thing with these analysis tools is not that they can tell you the right result, they can't, but they can tremendously helpful in being able to see what may be causing what you hear and then assisting in making the proper adjustments. You can spend all day with an RTA and EQ trying to adjust a frequency aberration caused by a phase issue and not fix it, while a more advanced analyzer will let you see that the problems is likely a phase issue to start with and recognize if it is one that can be fixed by delay or some other approach. Several of these analysis systems also provide a 'spectrograph' mode, think of it as an RTA that also lets you track it over time. On the screen you have one axis for frequency and another for time, the level is then indicated by color. You can also usually adjust the spectrograph so that you only see levels above some threshold, thus letting you set it to just see peaks and where feedback may be starting to build up.

I also wanted to reinforce that EQ is the last step in feedback avoidance. You always want to consider mic and speaker placement, mic and speaker patterns, nearby reflecting surfaces, etc. before resorting to EQ. For feedback EQ should be the last bit if needed and not the first thing you rely on.

If possible, I prefer parametric EQ for any system EQ, both system tuning and feedback. Ian explained the differences between a graphic and parametric EQ and this can relate directly to their use for avoiding feedback. Feedback is usually a very frequency specific effect and has a nasty habit of not occurring on the ISO octave or one third octave center frequencies. To address feedback with a graphic you may actually have to reduce other frequencies more than the offending one. And if the feedback frequency falls midway between two bands you may have to reduce a wide bandwidth in order to get the feedback frequency. A parametric EQ lets you use a narrow filter at a specific frequency, so it is much more effective against feedback with less effect on the rest of the signal. On the other hand, a parametric also lets you use filters of variable width, thus also letting you make gentle but wide ranging changes to the response for system tuning. The one place I do think a graphic EQ is a good option is for show specific qualitative tuning by the operator, it is more intuitive and easier to use for most people in that regards.
 
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Oh okay. Yeah I know what you're talking about with the faders, took me a little bit but then I remembered what the old board my church's youth group uses and I know what you are talking about. Thanks everyone for all the help! I now have got a general idea of all the different terms so I guess right now the only thing left for me to do is try it out. Thanks everyone for the help!
 
I find that for program EQ (such as the occasional "whump" from a vocal, indicating a narrow resonance someplace), RTAs and Smaart are not too useful, because the former don't have enough resolution and the latter's display is too slow. You just have to listen for the problem and then pull EQ sliders (or sweep the parametric) in order to find it, which can be difficult if it's a note that comes along only once in a while. If your musical knowledge is such that you know what the offewnding note is (A3 for instance), you can look on a chart and see what frequency it is (I believe A3 would be 220Hz).
 

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