EQ questions (Cutting highs/Boosting)

[Killamike49]

Some tiny little sounds at 20khz aren't gunna affect the mix.

Ever heard of 808s? I'm 95% percent sure they use extremely high frequencies in tandem with the low one you hear. Something about the high noises changing the way you hear the bass. I can hear this effect in J Coles Workout pretty clearly. I'm sure someone else has more info.

Hmm, when I run an 808 kit through a spectrum analyser nothing picks up at 20khz. :L

Me too. I was told it only comes out of a TR-808, which makes having one a bit better than getting a sample. Dude could've been chatting shit though, he just said it had something to do with psychoacoustic properties. The only reason i put stock into it, is i can hear high squeaks in alot of songs with 808s in them, and i feel like they would've taken those squeaks out if they didn't serve a purpose.

[ChadDub]

Have you ever tested your range of hearing? I generated some sines in audacity one time and I think around 17.5kHz was the highest I could hear.

Damn dude I'm sorry you live life lowpassed. That must suck.

I just generated a sweep in Audacity from 20khz to 18khz and I could hear all of it. It wasn't very defined until I got to around 19khz but I could hear it.

But honestly, LP'ing to 18khz really wouldn't make that big a difference, but it might make your stuff sound better and not as harsh.

[atticuh]

Some tiny little sounds at 20khz aren't gunna affect the mix.

Ever heard of 808s? I'm 95% percent sure they use extremely high frequencies in tandem with the low one you hear. Something about the high noises changing the way you hear the bass. I can hear this effect in J Coles Workout pretty clearly. I'm sure someone else has more info.

Hmm, when I run an 808 kit through a spectrum analyser nothing picks up at 20khz. :L

Me too. I was told it only comes out of a TR-808, which makes having one a bit better than getting a sample. Dude could've been chatting shit though, he just said it had something to do with psychoacoustic properties. The only reason i put stock into it, is i can hear high squeaks in alot of songs with 808s in them, and i feel like they would've taken those squeaks out if they didn't serve a purpose.

Low passing a signal with no to little high frequencies 6khz+ will still affect the nature of the sound to some degree, but this also depends on how much you're cutting, the resonance of the cut, and what kind of cut is being made. Now back to the subject of an 808: while an 808 kick has very little high frequency content, a low pass (assume 6db/octave because its an extremely gentle roll off) will still cause some of the amplitudes and frequencies of some of the fundamentals to shift due to phasing up and down the frequency spectrum from EQ (assuming no linear phase). Now because the resonance of the cut was low and an 808 kick has very little mid/high frequency content, the change to the sound is minimal and almost unnoticeable. Now if you try it with something like a cymbal or pad with lots of mid and high frequencies, like Sharm said, the sound is going to completely warp.

[bigdaveo11]

great discussions everyone...very helpful. I have been going by if it sounds good it is good method, while not boosting or cutting anything extremely radically (+ or - 20db). I was reading in another DSF thread about creating songs for club systems (which is my intention) and it was mentioned in there that club systems have "difficulty" reproducing some of those higher freqs we are discussing in this thread.

[e-motion]

Have you ever tested your range of hearing? I generated some sines in audacity one time and I think around 17.5kHz was the highest I could hear.

Damn dude I'm sorry you live life lowpassed. That must suck.

I just generated a sweep in Audacity from 20khz to 18khz and I could hear all of it. It wasn't very defined until I got to around 19khz but I could hear it.

But honestly, LP'ing to 18khz really wouldn't make that big a difference, but it might make your stuff sound better and not as harsh.

lol, wait some years and we'll talk again

[extremesociety]

My general tactic is to cut first, boost second. You'll find lots of times that there's one problem area and when you get rid of that everything else magically opens up. I think that's when mixing gets exciting. That eureka moment when you just cut one thing a bit and all of a sudden "Holy shit!" it works, it works.

[Artie_Fufkin]

Have you ever tested your range of hearing? I generated some sines in audacity one time and I think around 17.5kHz was the highest I could hear.

Damn dude I'm sorry you live life lowpassed. That must suck.

I just generated a sweep in Audacity from 20khz to 18khz and I could hear all of it. It wasn't very defined until I got to around 19khz but I could hear it.

But honestly, LP'ing to 18khz really wouldn't make that big a difference, but it might make your stuff sound better and not as harsh.

lol, wait some years and we'll talk again

Yes, age does that. You wipper snappers and your mosquito tones! Although...I'm 19. (maybe my headphones couldn't reproduce the frequencies, idk)
I sometimes wonder what it's like for dogs to hear that high stuff we can't. Or what it would be like to see IR, UV, or X-rays.

[jrisreal]

IMO, do what you have to do...and keep in mind the range of human hearing. You don't need any content at 25kHz, nobody will hear it and it will just eat up headroom. Cut mud and make space for other instruments...cut inaudible frequencies.

[bigdaveo11]

good point^ thanks guys.

[Sharmaji]

IMO, do what you have to do...and keep in mind the range of human hearing. You don't need any content at 25kHz, nobody will hear it and it will just eat up headroom. Cut mud and make space for other instruments...cut inaudible frequencies.

rule 1: never trust internet advice.

did a bit of investigating after everyone seems to believe they have to cut at 18khz; there's a ton of musically-relevant info above 20khz, the altering of which can clearly affect what's below it.

read this: http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

[Artie_Fufkin]

Idk, I'm feeling a bit skeptical about that study.
I wouldn't say there's a "ton" but maybe an ounce of musically relevant info if that brain wave stuff does affect perception and pleasure of sound. For all the instruments but the crash cymbal and keys jangling, the "percentage of power above 20kHz" was less than 7%. I would imagine that's negligible?

Either way, I don't think that rolling off the over 20kHz range would hurt nor would there really be enough of it to consume a significant bit of headroom unless something went crazy like you had your high hats turned way up and you had ring modulation on them! lol

[atticuh]

Idk, I'm feeling a bit skeptical about that study.
I wouldn't say there's a "ton" but maybe an ounce of musically relevant info if that brain wave stuff does affect perception and pleasure of sound. For all the instruments but the crash cymbal and keys jangling, the "percentage of power above 20kHz" was less than 7%. I would imagine that's negligible?

Either way, I don't think that rolling off the over 20kHz range would hurt nor would there really be enough of it to consume a significant bit of headroom unless something went crazy like you had your high hats turned way up and you had ring modulation on them! lol

True, but assuming that cutting inaudible frequencies does not adversely affect a sound is the wrong assumption to make.The implication of the study is that higher, inaudible frequencies do not necessarily need to be cut in order to preserve headroom, because these high frequencies carry very little weight to begin with. In fact, these inaudible frequencies do have a bearing on the audible frequencies and how we perceive them.

The common view is that energy above 20 kHz does not matter, but AES preprint 3207 by Oohashi et al. claims that reproduced sound above 26 kHz "induces activation of alpha-EEG (electroencephalogram) rhythms that persist in the absence of high frequency stimulation, and can affect perception of sound quality."

Don't take this and generalize: don't think there is a standard practice to cutting inaudible frequencies. It really depends on a case to case basis, but you have to ask yourself, are you doing damage to the sounds you're trying to mix?

[atticuh]

IMO, do what you have to do...and keep in mind the range of human hearing. You don't need any content at 25kHz, nobody will hear it and it will just eat up headroom. Cut mud and make space for other instruments...cut inaudible frequencies.

rule 1: never trust internet advice.

did a bit of investigating after everyone seems to believe they have to cut at 18khz; there's a ton of musically-relevant info above 20khz, the altering of which can clearly affect what's below it.

read this: http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

Awesome read! DSF needs more posts with academic cites/sources like these.

[Artie_Fufkin]

Keyword: "claims"..... Perhaps that stimulation could be harmful? Who knows? I think the research thus far has been inconclusive.

And of course there's no standard practice! Indeed, none of this should be taken for gospel. OP, do whatever you feel like.

[subfect]

I know this is an old adage, but "do what sounds good". I've boosted EQs by over 15dbs before, and then compressed the shit out of them and gotten some really cool saturation-style colouring.

[Artie_Fufkin]

I did huge boosts like that for bass guitar recently. It felt wrong but I really liked the clangy sound of it.

I was thinking about this topic today and started wondering if maybe babies like the sound of keys rattling because they have all this extra high content. Just some food for thought, yknow?

[paravrais]

Should you cut more than you boost? Yeah. Is it an unforgiveable sin to boost like some people make out it is? No. Just do what feels right yadda yadda yadda, practice makes perfect.