Ok, this is about psychoacoustics.
There is a commercial system marketed (some time ago) as "WAVES".
What it did is take a specific ratio of higher harmonics to create the illusion of a LOWER harmonic (aka fundamental) in the ear/brain. It works.
You can hear a lot more bass out of speakers that don't and can't reproduce frequencies as low as this system lets you hear. (In case you don't know about it or believe me, there are/were demos to be had - probably "plug-ins" as well). Also SRS does a bass enhancement thing, but that may be pure processing, dunno.
Just to be 100% clear the LOWER bass note DOES NOT EXIST, but you hear it as if it did.
I've found precious little on this method. I would like to know more about the specifics, aka the engineering behind it. Papers, and the like?
Apparently this works at all frequencies not just for bass - it's simply handy for bass... 😀
I'd like to learn more about it, since I am wondering if perhaps, maybe there is some happenstance in our playback systems that under certain circumstances might mimic this effect (not on purpose). Aka, is something that we hear explainable by this phenomenon - or not?
Any and all insights, information, etc. is appreciated.
_-_-
There is a commercial system marketed (some time ago) as "WAVES".
What it did is take a specific ratio of higher harmonics to create the illusion of a LOWER harmonic (aka fundamental) in the ear/brain. It works.
You can hear a lot more bass out of speakers that don't and can't reproduce frequencies as low as this system lets you hear. (In case you don't know about it or believe me, there are/were demos to be had - probably "plug-ins" as well). Also SRS does a bass enhancement thing, but that may be pure processing, dunno.
Just to be 100% clear the LOWER bass note DOES NOT EXIST, but you hear it as if it did.
I've found precious little on this method. I would like to know more about the specifics, aka the engineering behind it. Papers, and the like?
Apparently this works at all frequencies not just for bass - it's simply handy for bass... 😀
I'd like to learn more about it, since I am wondering if perhaps, maybe there is some happenstance in our playback systems that under certain circumstances might mimic this effect (not on purpose). Aka, is something that we hear explainable by this phenomenon - or not?
Any and all insights, information, etc. is appreciated.
_-_-
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Hi,
FWIW take a 100Hz bass note. It will have 200Hz, 300Hz, 400 Hz etc harmonics.
To suggest a lower note your only option is 50Hz, and the only way to do that is
to create harmonics at 150Hz, 250Hz, 350Hz etc, that is halve the the frequency
and create 3rd, 5th, 7th etc harmonics of that frequency. FWIW it only works in
the bass, it rapidly sounds pretty hideous (if it doesn't already) used higher up.
rgds, sreten.
FWIW take a 100Hz bass note. It will have 200Hz, 300Hz, 400 Hz etc harmonics.
To suggest a lower note your only option is 50Hz, and the only way to do that is
to create harmonics at 150Hz, 250Hz, 350Hz etc, that is halve the the frequency
and create 3rd, 5th, 7th etc harmonics of that frequency. FWIW it only works in
the bass, it rapidly sounds pretty hideous (if it doesn't already) used higher up.
rgds, sreten.
Philips used to do a fair bit in this area. Here is an article but I would expect there to be others, papers and patents given the nature of the company before they pulled out of consumer electronics.
This effect is even used in musical instruments for ages. Unfortunately I don't know the English term for the effect, in German it is called "Residuum Hören". The direct translation would be residual hearing but this one is already used for the remaining hearing abilities in people with hearing disorders. So maybe someone knows the English term for it.
The effect was used in pipe organs to synthesize low notes.
The fundamental that we perceive from ringing bells does also not exist physically. We actually perceive it through this psychoacoustic effect.
I would also guess that a piano for instance is too small physically to reproduce the fundamentals of its lowest notes with enough sound pressure for being perceived.
Bass guitar are often not able to fully reproduce the fundamentals of the lowest octave but we can still hear them exactly because of this effect. Mild nonlinearities can even help in this regard.
And yes, some speakers actualy give loud bass perception through increased distortion.
Regards
Charles
The effect was used in pipe organs to synthesize low notes.
The fundamental that we perceive from ringing bells does also not exist physically. We actually perceive it through this psychoacoustic effect.
I would also guess that a piano for instance is too small physically to reproduce the fundamentals of its lowest notes with enough sound pressure for being perceived.
Bass guitar are often not able to fully reproduce the fundamentals of the lowest octave but we can still hear them exactly because of this effect. Mild nonlinearities can even help in this regard.
And yes, some speakers actualy give loud bass perception through increased distortion.
Regards
Charles
I think it is called 'synthesized fundamental'. Bose were/are quite good at it.
If you ave a small enclosure that cannot reproduce a low bass note, you can detect such a low note and synthesize the harmonics with DSP. The listener will then perceive the low note even if it isn't there - the brain 'assumes' it must be there because of all the harmonics, and 'tells you' you are hearing it.
Jan
If you ave a small enclosure that cannot reproduce a low bass note, you can detect such a low note and synthesize the harmonics with DSP. The listener will then perceive the low note even if it isn't there - the brain 'assumes' it must be there because of all the harmonics, and 'tells you' you are hearing it.
Jan
Heaps of consumer products with small speakers use this already - TVs, Bluetooth speakers etc.
See:
https://www.youtube.com/watch?v=RM6kly1tL_M
The difficulty is in generating harmonics without also generating IMD, which sounds bad and just gives the same effect as driving a small speaker too hard. If you want to avoid generating IMD then you basically need to use digital synthesis.
See:
https://www.youtube.com/watch?v=RM6kly1tL_M
The difficulty is in generating harmonics without also generating IMD, which sounds bad and just gives the same effect as driving a small speaker too hard. If you want to avoid generating IMD then you basically need to use digital synthesis.
Assuming the research Heerens and de Ru made is valid (google "Applying Physics Makes Auditory Sense"), the brain doesn't make it up, rather it is actually there because the ear physically creates tons of IMD *before* the signals hit the hearing cells.
Their theory (the ear's construction differentiates and squares the incoming SPL signal) also offers a lot of explanations to hearing phenomena that can't be explained otherwise, as of yet. Everybody can recreate their experiements, they even provide a piece of helper software for generating the test signals. I did, and it's quite embarassing at first and left me puzzled but after a while I got what it really means for audio (re-)production....
I've been on the lookout for a standalone unit that'll do this for a while. Figure it'll be useful for small-ish PA systems where they want bass, but no subs.
I think Peavey's IPR amps have some DSP in there that can do it, called MaxxBass
https://peavey.com/products/index.cfm/item/667/116956
Chris
I think Peavey's IPR amps have some DSP in there that can do it, called MaxxBass
https://peavey.com/products/index.cfm/item/667/116956
Chris
It works in a very simple way:
Split the original signal into high and low sections.
Distort the lowpass section.
Bandpass the distorted lowpass section.
Mix the high section of the original signal with the distorted and bandpassed lowpass section.
The difficulty is in what filters to use and what kind of distortion to use.
There's a AES paper on it, I'll try to find it.
Edit: Found.
http://www.aes.org/e-lib/browse.cfm?elib=8288
http://www.aes.org/e-lib/browse.cfm?elib=17281
Split the original signal into high and low sections.
Distort the lowpass section.
Bandpass the distorted lowpass section.
Mix the high section of the original signal with the distorted and bandpassed lowpass section.
The difficulty is in what filters to use and what kind of distortion to use.
There's a AES paper on it, I'll try to find it.
Edit: Found.
http://www.aes.org/e-lib/browse.cfm?elib=8288
http://www.aes.org/e-lib/browse.cfm?elib=17281
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There was even a newer article in the JAES dealing with this. They made subjective tests with different nonlinearities. IIRC the prefered one was an e-function with offset.
There was also a WW article (of which I have a copy somewhere) from the fifties, where they used a triode with the bias intentionally chosen such that it generates a lot of harmonics.
Regards
Charles
There was also a WW article (of which I have a copy somewhere) from the fifties, where they used a triode with the bias intentionally chosen such that it generates a lot of harmonics.
Regards
Charles
yes, they call it MaxxBass too now.
Not being an AES member I don't have direct access to the paper(s). 🙁
If magic happened and privately copies somehow appeared, how great would that be? 😀
I did understand that they take the higher harmonics. My interest in as far as what ratios and amplitudes cause the effect to appear? That may be in the papers?
Perhaps I ought not share this conjecture/speculation, but I thought I would look at this to see if there might be a relationship or correlation between the way this works and the way in some cases amplification with "higher" levels of low order harmonic distortion (and usually nil higher order) often do sound more euphonic and pleasing compared to amplification with merely nil harmonic distortion...
...doing only mental gymnastics it occurred to me that on the face of it, more 2nd, 3rd,4th order distortion ought to accentuate (more annoying) and not reduce the subjective perception of things like sibilence and cymbals, thin guitar notes, upper tones of harpsichords... I was thinking why?
_-_-
Not being an AES member I don't have direct access to the paper(s). 🙁
If magic happened and privately copies somehow appeared, how great would that be? 😀
I did understand that they take the higher harmonics. My interest in as far as what ratios and amplitudes cause the effect to appear? That may be in the papers?
Perhaps I ought not share this conjecture/speculation, but I thought I would look at this to see if there might be a relationship or correlation between the way this works and the way in some cases amplification with "higher" levels of low order harmonic distortion (and usually nil higher order) often do sound more euphonic and pleasing compared to amplification with merely nil harmonic distortion...
...doing only mental gymnastics it occurred to me that on the face of it, more 2nd, 3rd,4th order distortion ought to accentuate (more annoying) and not reduce the subjective perception of things like sibilence and cymbals, thin guitar notes, upper tones of harpsichords... I was thinking why?
_-_-
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By the way, this is how some musical instruments work. They actually have very little output at the perceived fundamental. I remember (ages ago!) Dr. Leach talking about working with a high school student to analyze the output of an instrument. Perhaps a sax? I can't remember the specifics. They were quite surprised to discover the main output was in overtones and not the fundamental.
Cool to see this being used.
Best,
Erik
Cool to see this being used.
Best,
Erik
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well I bit the bullet and joined AES for a year - but the website won't let me login. heh.
...no telling what's up, I can change my password, but not login. Hmmm.
figured I'd get enough pdfs out of the deal to make it worth it, if only for reading material...
...maybe I'd have been better off buying more Linear Audio issues?? 🙄
...no telling what's up, I can change my password, but not login. Hmmm.
figured I'd get enough pdfs out of the deal to make it worth it, if only for reading material...
...maybe I'd have been better off buying more Linear Audio issues?? 🙄
The effect you are talking about Bear is well known by mastering engineer, broadcaster, etc, etc,...
The Israelian Wave company (professional plug ins for daw) actually produced the maxbass plug ins and harware and other dedicated units and made a name with it (and some mastering limiters in harware you ll find in nearly every mastering facility, the L1 ultramaximizer but it s an other story).
The principle at work are already been described in previous post for this units.
An other brand that make same kind of treatment is SPL a deutsch brand specialized in this kind of treatment too. There own harware unit use tubes and some passive eq to produce the effect, it s the Tube Vitalizer. Try to find the user manual there is some explanations about thir own way of doing the effect and its quite interesting (and inspired by studio units from the 50's/ 60's so nothing really new).
To find ratio and level of differents harmonics and their effects try to find an additive synthesis synthesizer this is all about this. Some hardware one's can be found at Kawai, the K5000 especially but it s a nightmare to program (not really ergonomicaly optimised given the number of parameters involved). Nowadays some plug or software additive synthesizer should exist probably easier to program but i don't know them: you'll have to search for them. Or find an hammond b3 which is some crude version of additive synthesis. 🙂
What your talking about for the high uing this kind of effects is called an exciter. Aphex was the first brand to exploit the principle with the Aural Exciter in the end of 70's beginning of 80's. Many brands used the principle including Bbe, Spl, dbx,... for the treble it is usual to have some action on phase relationship with level and harmonics.
It is difficult to use because you will be accustomed rapidly to the effect and this is difficult not o be heavy handed with it.
try to find Ozone soft/plug if you want to try these effect by yourself.
The Israelian Wave company (professional plug ins for daw) actually produced the maxbass plug ins and harware and other dedicated units and made a name with it (and some mastering limiters in harware you ll find in nearly every mastering facility, the L1 ultramaximizer but it s an other story).
The principle at work are already been described in previous post for this units.
An other brand that make same kind of treatment is SPL a deutsch brand specialized in this kind of treatment too. There own harware unit use tubes and some passive eq to produce the effect, it s the Tube Vitalizer. Try to find the user manual there is some explanations about thir own way of doing the effect and its quite interesting (and inspired by studio units from the 50's/ 60's so nothing really new).
To find ratio and level of differents harmonics and their effects try to find an additive synthesis synthesizer this is all about this. Some hardware one's can be found at Kawai, the K5000 especially but it s a nightmare to program (not really ergonomicaly optimised given the number of parameters involved). Nowadays some plug or software additive synthesizer should exist probably easier to program but i don't know them: you'll have to search for them. Or find an hammond b3 which is some crude version of additive synthesis. 🙂
What your talking about for the high uing this kind of effects is called an exciter. Aphex was the first brand to exploit the principle with the Aural Exciter in the end of 70's beginning of 80's. Many brands used the principle including Bbe, Spl, dbx,... for the treble it is usual to have some action on phase relationship with level and harmonics.
It is difficult to use because you will be accustomed rapidly to the effect and this is difficult not o be heavy handed with it.
try to find Ozone soft/plug if you want to try these effect by yourself.
tnx, I don't need to try the effect myself - quite familiar with Waves/MaxxBass as it sounds, having seen it and heard it when it was first introduced.
I'm looking for a potential correlation as per my more recent post. Perhaps it exists, perhaps not.
I'm looking for a potential correlation as per my more recent post. Perhaps it exists, perhaps not.
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