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Re: Resonant Undertones

Posted: Mon Sep 04, 2017 7:35 pm
by guitardood
Don't know if it's a good solution, but one I used was Melodyne.

I had a guitar solo which had some weird low undertones on a few sustained notes. What I did to clear them up was to load the track into Melodyne polyphonic mode, located the undertones and pulled the volume way down on them until the notes sounded natural. Just deleting them kind of ruined the sound, but lowering the level of just those undertones helped save an otherwise great take.

Re: Resonant Undertones

Posted: Wed Sep 06, 2017 7:24 am
by philbrown
Rick, this is admittedly a kind of lame suggestion, but of course I'll post it anyway. I have found various high-pass functions of different EQ's to sound pretty different from each other. Not sure how much of that is the curve itself or just part of inherent 'character' of the EQ/phase anomalies etc. I have a couple I tend to lean toward and MWEQ isn't one of them. I mostly use UA's Harrison EQ for that and lately PSP McQ which is an MCI console EQ emulation. It's worth trying different ones at different settings but may not solve your specific issue of course. My wife's Moog Sub 37 that we use for bass has a ridiculous amount of low end so I've gotten to know my high-passes pretty well.

Re: Resonant Undertones

Posted: Wed Sep 06, 2017 1:20 pm
by Rick Cornish
philbrown wrote:Rick, this is admittedly a kind of lame suggestion, but of course I'll post it anyway. I have found various high-pass functions of different EQ's to sound pretty different from each other. Not sure how much of that is the curve itself or just part of inherent 'character' of the EQ/phase anomalies etc. I have a couple I tend to lean toward and MWEQ isn't one of them. I mostly use UA's Harrison EQ for that and lately PSP McQ which is an MCI console EQ emulation. It's worth trying different ones at different settings but may not solve your specific issue of course. My wife's Moog Sub 37 that we use for bass has a ridiculous amount of low end so I've gotten to know my high-passes pretty well.
Thanks, Phil. Going to give it a try. This one is a bugger.

Re: Resonant Undertones

Posted: Thu Sep 07, 2017 5:43 am
by daniel.sneed
In case the undertones are loud enough, you may try to *see* them in RX6 Spectral Repair.
If you do *see* them, then deleting them is a breeze.
BTW it will bring no audible artefacts.

Re: Resonant Undertones

Posted: Sat Sep 09, 2017 1:55 pm
by Rick Cornish
daniel.sneed wrote:In case the undertones are loud enough, you may try to *see* them in RX6 Spectral Repair.
If you do *see* them, then deleting them is a breeze.
BTW it will bring no audible artefacts.
Hi Dan.....
Thanks for the note. I did bring it into RX6, and was able to see the low fundamental of the tone and first overtone, but I couldn't get the other overtones out without compromising the sound. Maybe I need to work harder on this.

I've tried everything I can think of to remove vibrations from the guitar (tightened everything, felt under the pickguard, etc.) and it still happens. The most noticeable artifacts are when I play a high triad on the highest strings that contains a major second:
• G (3rd string/12th fret)
• C (2nd string/13th fret)
• D (1st string/10th fret)

The undertone that's produced is around C2 (65.41Hz) with a strong overtone at C3 (130.81Hz). There is also some low distortion happening, which I'm still trying to chase. This is all very subtle on first listen, but after a while, it's all I hear. Frustrating. :deadhorse:

Re: Resonant Undertones

Posted: Mon Sep 11, 2017 2:20 pm
by Gravity Jim
Do you hear this tone when simply playing the guitar, or only in the recording?

Re: Resonant Undertones

Posted: Tue Sep 12, 2017 6:28 am
by Rick Cornish
Gravity Jim wrote:Do you hear this tone when simply playing the guitar, or only in the recording?
Hi JIm—I can hear it acoustically (however subtly, as my HR Fusion III isn't really an "acoustic" guitar). I've tried tightening down all the parts (pickguard, etc.), but—short of damping all the (admittedly minimal) acoustic properties of the instrument, I can't defeat it.

Re: Resonant Undertones (Now Understood, Still Not Solved)

Posted: Wed Nov 08, 2017 9:34 am
by Rick Cornish
OK—Today I came across a new video by Adam Neely (who, if you aren't familiar, has a video blog on YouTube where he discusses all kinds of interesting and occasionally weird musical stuff).

In his blog post, "The Third Sound," Adam identifies the source of the sounds I've been hearing: They are "Combination Tones" or "Tartini Tones"… also known as "Otoacoustic Emissions." It's a weird psychoacoustic phenomenon explained pretty well by Adam here: https://www.youtube.com/watch?v=73_CiAYX00k

I still haven't figured out how to get rid of them (or even if that's possible), but this is a start. Interesting stuff.

Re: Resonant Undertones

Posted: Wed Nov 08, 2017 10:45 am
by stubbsonic
Fascinating video. I had always assumed that those tones were the result of "beats" at high rates to form pitches. Was he suggesting it might be something else, too?

Re: Resonant Undertones

Posted: Thu Nov 09, 2017 4:48 am
by Phil O
He hit the nail on the head when he said, "Is there a metaphor you can use to over simplify things so I can understand it?" He did some of that in this video. I studied some of this stuff when I was teaching at an engineering school and setting up an audio program there. It's not as psychoacoustic as he suggests. A lot of it is pure physics and the answers are buried in the math (which he really didn't get into). The bit about the ear producing its own sound is a real physical phenomenon (more math). It happens in the ear (not in the brain)... And it can happen in Rick's guitar too. Just sayin'. 8)

Don't get me wrong. I'm not saying psychoacoustics doesn't exist. Im just saying I think Rick's problem is purely physics.