Odd Question about EQ Frequencies

One factor would be that the overtones above the source frequency define our comprehension of detail more than the source frequency itself.
EG the 7k sibilance issues.

Oh and if memory serves you have your main note, say A 440. So the main sound of that note resides at 440hz obviously but the overtones will cause frequency spikes at 220hz, 110hz and in the opposite direction 880hz. Basically the overtones appear at double the hz (octave above) or half the hz (octave below). So by adjusting those points of the frequency range you are in fact adjusting part of that overall tone... just the more subtle parts of it that contribute to the timbre.
 
Kind of a mangled interpretation but I can pull out my notes on the matter if you like. Cheers.

One fascinating study I did was to find the source freq. of a bass (sweeping a narrow Q) and then did a narrow Q boost on it AND it's harmonics (EG 50,100,200,400,800,1600) and pulled the rest down.
Then I pulled those freqs down on other trax.
It makes an incredibly clear, punchy bass without masking or gain.

M Glenn... Yes indeed. It is such an amazing subject and EQ is so full of possibilities I get excited just thinking about it. Looking at this document I made while watching the G3 vid is making me want to jump right into mixing my album but I have a ton of time correction, editing and overdubs to do before I get to that. *sigh*
 

I understand the confusion... or I think I do. I think konradh is looking at the "fundamental tones" and their place on the frequency spectrum and wondering why adjusting seemingly unrelated frequencies would have such a drastic effect on the sound. The simple answer would be that they are very much related because there is more than just that fundamental tone in play. If it were just the fundamental tone then all we'd hear is just a mechanical sounding "beeeep".
 
I may be terribly wrong but I know that used to confuse the heck out of me as well.

This to me is where the science of this stuff loses people and why at times I think it should totally be removed from the foundation.
 
Let's take a look at frequencies and tuning. Just because something exists in a chord or single note doesn't mean that frequency is dominating on a recording. Just because people high pass every instrument 9 out of 10 times doesn't mean they HAVE to if the instrument in question does not need to be high passed at the source.
 
Just because 600-800 Hz can bring on mid range congestion in a guitar doesn't mean we have to remove it "just because". If the sound was printed with these fequencies curbed already, you'll most likely need to boost them.
 
Sure 10k or 12k is off the scale for a voice....you're not supposed to blast those freq's in a mix. They create air...whisper...presence....texture...you just can't put this type of a numeric value on this stuff when you are dealing with sound sources. The reason being, each sound source is different. You don't low pass if you don't hear anything harsh...and even if you do, before you just low pass, it's best to try and find out where the source of the harshness is before you just low pass and destroy all the good stuff in the high end.
 
Now with that said, if someone is having an issue with an instrument as far as eq goes, when everything else has failed, yeah, I bring up my little chart that tells me all the Hz of notes and I try and deal with things that way. But this is only with instruments that are driving me crazy like low tuned guitars or basses. When a guitar or bass is tuned to a low B or even a low A, you have to first figure out what notes they are playing that may be giving you problems. Not all notes will bother you so you wouldn't just set up shop to handle low B or low A. The tuning makes other notes weird too...so you need to decipher what they may be. I've set up automation of mutli-band compressors to handle when instruments go astray depending on the notes they play. Just about always....they are frequencies that wouldn't have anything to do with those instuments...and this is due to over-tones.
 
See, that's the whole thing in a nutshell. Just because something is tuned to something or has this, that, and this element of a frequency in the sound, doesn't mean the frequency EXISTS enough in the sound to alter it. This is where you have to throw some of the science stuff right out the window and use your ears. If I'm chugging on an A chord with a heavily driven guitar, I can just about promise you that 119 Hz will show up as that seems to be the "whoomfing" frequency in a driven guitar that sticks out. Does it make sense? Sorta kinda it does...yet, 119 isn't in an A. The closest to it in the range we would be playing would be a B at 123 Hz and of course the A chord we'd be rooting from would be 110 which IS an A. However, 110 usually doesn't show up for me. I've seen 106, 100, 92, but never the elements that literally make an A.
 
So my point is, you're not always going to get results by using the numerical values "that make up a sound". Some of those charts weren't created with the sounds we use today. Seriously. If you use a normal, clean elelctric guitar, yeah, you'll get close to those numbers if not spot on...but again, it depends on how much of those frequencies are included in your eq curve. Add distortion and the game changes. Pop/slap a bass, then what do you do? The numbers won't jive with the numerical bass values, that I promise you.
 
Those numbers are all based on:
 
The human voice ranges from this to this...
A guitar ranges from this to this...
A piano ranges from this to this...
 
You get the idea. As soon as YOU create the sound with a mic or use effects like distortion or something, those numbers change. What if you're a bass prostitute and like a lot of low end in your piano you just mic'd up? Right...you'll see low end that wouldn't normally show in a piano.
 
What if you love high end in your guitar tones because you're going deaf? Right...you'll see high end that wouldn't normally be in a guitar tone.
 
What if you use a mic that just has one of those phased sounds....or one that doesn't really project like a decent mic would? Right...you'll see an eq curve pop up on an analyzer that will make your head spin that won't have the "human voice" ranges in it. So me personally, I don't read into any of those charts or graphs that were created as starting points for us. OUR instrumentation of today goes totally against those grains. See for yourself. As soon as you take into consideration all that I'm saying, the charts change drastically and are not even worth considering depending on the style of music you are working with as well as how you record.
 
You mention high passing a bass just passed it's lowest musical note....I sure don't do that. Why? Because the sounds that come in to me from clients need to be treated for what they are, not what some number tells me. I sweep through the bands via high pass until I get what I'm looking for. It could be 40 on down....it could be 90 on down...it could be 120 on down. It depends on how much eq is recorded with the sound at the sound source. You just can't look at numbers for any of this stuff in my humble opinion, but that's just me. Science hasn't shown me anything in this field that has made me a better engineer. The only good thing science has done for me was to introduce me to cool cats like bitflipper and DrewFx. :)
 
-Danny

And to Danny, Thanks as always for the thorough and thoughtful post.  Regarding the bass, I was just citing a quick example.  What I really do is to sweep the HPF until I hear any bad rumble or noise in the bass go away without taking any of the desired body out of it.  The number is just sort of a quick guideline.  If I am often using the same bass or bass sample, and I know where the bottom string frequency lies, I have a good starting point.
 
Your comments, of course, are correct.  Thanks.

The issue is that the related harmonics (odd and even ordered) are an amalgam which interacts with the fundamental causing the fundamental to change. If a certain higher odd-ordered harmonics exist that can interact negatively with the fundamental (and other harmonics), adjusting the fundamental will not correct the issue. However, locating and eliminating the harmonics that are interacting with the fundamental in a bad way will have a large effect, even if the harmonic itself is inaudible.
 
So the issue is not what harmonics are present, the issue is the overall effect that they have on the timbre.
 

Well I just like that now I have some guidelines to work with. I definitely use my ears but having some starting points and knowing approximately where I might want to cut or boost is helpful. I guess I wasn't very helpful here. :-/

@Danny... Yeah, I certainly never liked "rules" when it came to tone (you've heard what I did with my guitar tone stumbling around in the dark with just some sims and a bit of elbow grease) and really guitar is easy for me in that regard. It's all the other stuff that just bends my head. Like you heard how non existent my kick drum sound was on that very same track where the guitars were cutting... and everything else was flat. Just the idea of taking a standard kick sound, using a high pass just to snuggle up to the very bottom of the signal, low pass to get rid of annoying room noise and bleed then finding the beater click to get some attack is the type of thing I wouldn't have in a million years thought to do. And that's before even compressing or gating or whatever. I would have just turned dials until it sounded okay... which obviously is cool but then in comes everything else and all is lost. I guess for a n00b like myself having that kind of structure helps to begin with. Believe me I intend to go absolutely apeshizzle once I get accustom to stuff and if the "guidelines" aren't making my heart pound they will certainly go out the door but now that I'm actually starting work on one of my old albums I did some very basic rough mixing to get through the editing process without making my ears bleed and wow... what a difference a little knowledge makes. Took me no time to dial things in the way I envisioned them to be. I'm really pumped to dig right into the mix but I must be patient.
 
Certainly not arguing though (I would never argue your methods... you're stuff just sounds too damn good). I was just lost and intimidated before when looking at all the fancy knobs, graphs and doodadads. Not so much now. Just need the bleeding program to work properly. lol
 
Cheers, buddy.

I have learned that it's ok to experiment by playing with things like the FX Chains Templates and the factory eq settings that come with some plugs and devices. Some are radical. It's fun. On a track a while back I did total vocal silliness passing only a small range of sound. It made for a fun and different track. I enjoy both mixing for a strictly natural sound that works on most systems as well as forgetting natural and using the tools to get something that draws in the listener.
 
I think it's silly to pretend that some how the engineer is transparent. Frankly, I've started wondering as I listen whether certain ideas are the artists or the engineers. "Did that sound like that during the original performance?"
 
And I'm sometimes startled by the disdain some have for the art of mixing. Some people will listen to a mix and like it based on how parts were performed performed rather than by what it sounds like. My mom was listening to a recording of my kid singing a Xmas carol and she wanted asked how it was created. I said I just hit the good song button and it just happened.
 
:-)
 
I also love bits where you can hear the musician thinking (think imperfect). Note sequences that would rarely result from thought through melody design can rise up. And the fact that you can hear the musician thinking is so awesome to me... especially when the lines work.

Dude Ivey, Don't worry about it.  If you are getting stuff to sound good, you obviously have all the skill you need!