Welcome to the Piano World Piano Forums
Over 2 million posts about pianos, digital pianos, and all types of keyboard instruments
Join the World's Largest Community of Piano Lovers (it's free)
It's Fun to Play the Piano ... Please Pass It On!

Gifts and supplies for the musician
SEARCH
the Forums & Piano World

This custom search works much better than the built in one and allows searching older posts.
Ad (Piano Sing)
How to Make Your Piano Sing
(ad) Pearl River
Pearl River Pianos
(ad 125) Sweetwater - Digital Keyboards & Other Gear
Digital Pianos at Sweetwater
(ad) Pianoteq
(ad) P B Guide
Acoustic & Digital Piano Guide
Who's Online
171 registered (accordeur, 36251, ajames, A-Tom, A Guy, 42 invisible), 1828 Guests and 18 Spiders online.
Key: Admin, Global Mod, Mod
Quick Links to Useful Piano & Music Resources
Our Classified Ads
Find Piano Professionals-

*Piano Dealers - Piano Stores
*Piano Tuners
*Piano Teachers
*Piano Movers
*Piano Restorations
*Piano Manufacturers
*Organs

Quick Links:
*Advertise On Piano World
*Free Piano Newsletter
*Online Piano Recitals
*Piano Recitals Index
*Piano & Music Accessories
*Music School Listings
* Buying a Piano
*Buying A Acoustic Piano
*Buying a Digital Piano
*Pianos for Sale
*Sell Your Piano
*How Old is My Piano?
*Piano Books
*Piano Art, Pictures, & Posters
*Directory/Site Map
*Contest
*Links
*Virtual Piano
*Music Word Search
*Piano Screen Saver
*Piano Videos
*Virtual Piano Chords
(ad) Estonia Piano
Estonia Pianos
Topic Options
#2361342 - 12/13/14 03:52 PM Another check for the low bass-the 7th harmonic
GMG Offline
Junior Member

Registered: 06/22/12
Posts: 7
Loc: Victoria, Australia
Hi all,
the last few years I've been using the interval of a minor 7th to tune in the bottom octave. I usually start from A1 descending to C1 before it starts to become murky. I listen for the 7th harmonic of the bottom note and where it coincides with the 4th harmonic of the top note. Eg: for the minor 7th interval A1-G1, theoretically the bottom note is 55H2 and the top note is approx. 98Hz, the 7th harmonic of A1 is 385Hz and the 4th harmonic of G2 is close to 392Hz giving a beat rate of 7BPS. It's easy to hear these two coincident partials in this area and gives another check to see if you are on track heading into the bottom octave. I then aim to get a nice smooth progression of ever slower beating minor 7ths as I'm descending. It's also good to have an interval that fits easily in the LH while the other hand can stay on the hammer. It becomes too murky for me around B0 but it really helps avoid tuning either too sharp or too flat in this region. It's also helpful to have a fast beating test in this region. I'm a big fan of the min3rd/maj6th test down through the tenor and bass but it gets slower and harder to hear in the low bass, especially on pianos that aren't great. I'm also checking with 10ths, 17ths and octaves lower down. Anyway I hadn't come across this check anywhere else and was wanting to know if others are using this too. I'm an aural tuner so I'm always looking at new ways to listen and new checks. A few years ago I started using Bill Bremmer's "Mindless Octaves" in the treble and found it invaluable. Thanks
_________________________
muso, part time tech.

Top
(ad PTG 757) The Value of PTG Membership
The Value of a PTG Membership
#2361486 - 12/14/14 08:31 AM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
gynnis Offline
Full Member

Registered: 02/16/14
Posts: 250
Loc: Florida, Connecticut
Sounds like a good idea. I use 17th and higher odd harmonics as a final check. If you have a piano with rich odd harmonic structure it really improves the integration of the bass.
_________________________
Seiler 206, Chickering 145, Estey 2 manual reed organ, Fudge clavichord, Zuckerman single harpsichord, Technics P-30, Roland RD-100.

Top
#2361595 - 12/14/14 02:33 PM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
SMHaley Offline
500 Post Club Member

Registered: 05/06/13
Posts: 847
Loc: Seattle
I use various harmonics tuning the bass depending on the scale and quality of that part of the compass. Some pianos are pretty lousy down there and sometimes an educated guess is about is good as it can get.
_________________________
AA Music Arts 2001, BM 2005
Pipe Organ Builder
Chief Instrument Technician, Chancel Arts
Church Music Professional

Baldwin F 1960 (146256)
Zuckermann Flemish Single

Top
#2361638 - 12/14/14 05:01 PM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
rxd Offline
1000 Post Club Member

Registered: 03/11/09
Posts: 1801
Loc: London, England
For me and other colleagues, tuning is, first and foremost about creating musically useable intervals. Compromising some in order to ameliorate others. Usually Subtly compromising sbi's a little more in order to slow down the rbi's.

The minor seventh is one of the really embarrassing intervals of equal temperament and also in string and wind ensembles with more flexible intonation. A minor seventh or its compounds in the mix, particularly a series of chords containing minor sevenths creates a situation where melodic intonation is difficult to reconcile withe harmonic intonation. When coaching groups, I mention that it is difficult unless one resorts to early music type intonation and invariably modern musicians reject that idea. Flattening the bass makes the situation worse.

It is wise to keep control over the potentially worst sounding intervals by using them in tuning but never exclusively.

In going into the bass I'll tune a good octave first (this is easy in a large piano and everything else falls in line but well nigh impossible in some smaller pianos, including some seven foots) then i check 5th and M3, changing the M3 to M10 or 17 for convenience as I progress.
Further toward the single strings I begin to lose interest in the finer points of smooth progression but take each interval on its own individual merits. It usually finishes up quite even but it is not my priority.

Small pianos are a whole different matter. It is even more about intervals for me. I see no point at all in matching only one pair of coincidental partials at the expense of all others. Particularly when it involvs sticking doggedly to one type of octave no matter how it makes other intervals sound. Might just as well have none of them match .... but that's heresy.

Bass string making has improved greatly over the past few decades but there are sometimes impossible tuning situations, even in better pianos.

I will use every test I can think of including the tests for 6.3, 4.2 and 2.1, usually finding that none of them are anywhere near each other then finally, once I'm in the ballpark, tune to the octave above to where it sounds cleanest. Often this isn't much. All too often I have found a lower unison in tune but the pitch unacceptable when played as an octave. After reconciling all the intervals then finally putting the octave where it sounds best globally, I find that when I take the wedge out to put the unison in, I haven't changed the pitch very much at all yet the octave sounds 1000% better. The audible partials are so close together that the slightest change will make a huge difference. I'll usually sound the octave when putting in the unison then finally testing it alone.

Short story, two days ago I tuned one of the retired Elton John 7' Yamahas that resides now in a BBC pop music studio. It is typically Yamaha bright and a bit neglected tonally, now and I have to stretch the bass more than I normally would. For some reason, the piano was to be used for a classical piano trio promo spot. I wasnt aware of this ehen i tuned it (they never tell us much)The pianist, a well known session player and friend of mine was, amazingly, even to me, playing with a perfectly covered sound. I hardly recognised the piano tone when I caught the end of the rehearsal when I went back for the second tuning. I could hear that I had room to tune the bass as i would have preferred, interval wise for a piano trio but there wasn't time. It's spectacular the difference a great player can make.
_________________________
Concert & Recording tuner-tech, London, England.
"in theory, practice and theory are the same thing. In practice, they're not." - Lawrence P. 'Yogi' Berra.

Eschew obfuscation.



Top
#2361804 - 12/15/14 08:31 AM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
Mark Cerisano, RPT Offline
1000 Post Club Member

Registered: 01/24/10
Posts: 1483
Loc: Montreal, Quebec, Canada
Those are good but keep in mind where these suggestions come from.

For example, often technicians recommend keeping a smoothly increasing beat speed of M17 in the treble, but why? Because that's ET? But beating 17ths are not musically appealing on their own.

However, if one thinks of the M6/M17 test, you can see that as we tune consistently pure 12ths (or consistently tempered 12ths which allow pure 22nds to evolve) we are mirroring the smoothly increasing M6 in the temperament AND creating superior compound SBI.

It is dangerous to create smooth RBI for their own sake and not know why.

If you like Bremmer's mindless octaves for the treble, read up on Virgil Smith's Natural Beat for the bass. He advocates listening to the beating of the fundamental of the lower bass note and tuning that pure. There's no published proof, that I've found, that scientifically explains why that would work, but I use it with success.
_________________________
Mark Cerisano, RPT
www.howtotunepianos.com

Top
#2361832 - 12/15/14 09:33 AM Re: Another check for the low bass-the 7th harmonic [Re: Mark Cerisano, RPT]
rxd Offline
1000 Post Club Member

Registered: 03/11/09
Posts: 1801
Loc: London, England
Originally Posted By: Mark Cerisano, RPT


........ read up on Virgil Smith's Natural Beat for the bass. He advocates listening to the beating of the fundamental of the lower bass note and tuning that pure. There's no published proof, that I've found, that scientifically explains why that would work, but I use it with success.


Are you sure you mean listen to the fundamental of the lower bass note and tuning that pure....
To what??? What else is down there to tune it to?

I had many a conversation with Virgil and he always made sense.
the way this reads doesn't make sense to me. Please clarify.

'Listen to the fundamental of the upper note and tune to that' sounds more like something Virgil would have said. Of course, this would imply a 2-1 octave
_________________________
Concert & Recording tuner-tech, London, England.
"in theory, practice and theory are the same thing. In practice, they're not." - Lawrence P. 'Yogi' Berra.

Eschew obfuscation.



Top
#2362123 - 12/15/14 09:43 PM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
Mark Cerisano, RPT Offline
1000 Post Club Member

Registered: 01/24/10
Posts: 1483
Loc: Montreal, Quebec, Canada
I believe he advocated a "natural beat" at the fundamental of the lowest note. I read it in his book "New Techniques for Superior Aural Tuning", but that was a while ago.

If he didn't, that's how I understood it and that's one way I'm tuning bass octaves. I am very happy with result whereas before I wasn't. I rationalize that it may be a combination of all the neighbouring partials, which produce difference tones equal to the fundamental. (8-7=7-6=6-5=5-4=4-3=3-2=2-1=1, the natural beat).

I find it easier to hear when playing the octave loudly.

Surely someone must have this same experience.
_________________________
Mark Cerisano, RPT
www.howtotunepianos.com

Top
#2362260 - Yesterday at 08:34 AM Re: Another check for the low bass-the 7th harmonic [Re: Mark Cerisano, RPT]
prout Online   content
500 Post Club Member

Registered: 11/14/13
Posts: 898
Originally Posted By: Mark Cerisano, RPT
I believe he advocated a "natural beat" at the fundamental of the lowest note. I read it in his book "New Techniques for Superior Aural Tuning", but that was a while ago.

If he didn't, that's how I understood it and that's one way I'm tuning bass octaves. I am very happy with result whereas before I wasn't. I rationalize that it may be a combination of all the neighbouring partials, which produce difference tones equal to the fundamental. (8-7=7-6=6-5=5-4=4-3=3-2=2-1=1, the natural beat).

I find it easier to hear when playing the octave loudly.

Surely someone must have this same experience.





The 'natural beat' you refer to sounds as if it is the 'resultant', a beat we hear that is produced by the brain, but is not actually measurable.

Obviously, with iH, 8-7 does not equal 7-6 nor any other difference of sequential partials. That only works with harmonics.

Given inharmonicity, the only way to tune the octave 'pure' using that technique, would be to tune the octave narrow, using the loudest set of sequential partials as a reference.

Edit reason: Attempt at improved clarity.


Edited by prout (Yesterday at 08:38 AM)

Top
#2362262 - Yesterday at 08:43 AM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
Mark Cerisano, RPT Offline
1000 Post Club Member

Registered: 01/24/10
Posts: 1483
Loc: Montreal, Quebec, Canada
As with many things piano tuning related, they often go unexplained yet practiced with acceptable results.

I'm still burning with curiosity. Hasn't anybody else read about this bass octave technique by Smith, and doesn't anybody else use it?

I'm going to have to look for my copy of his book. I'll get back to you.
_________________________
Mark Cerisano, RPT
www.howtotunepianos.com

Top
#2362267 - Yesterday at 08:53 AM Re: Another check for the low bass-the 7th harmonic [Re: Mark Cerisano, RPT]
prout Online   content
500 Post Club Member

Registered: 11/14/13
Posts: 898
Originally Posted By: Mark Cerisano, RPT
As with many things piano tuning related, they often go unexplained yet practiced with acceptable results.

I'm still burning with curiosity. Hasn't anybody else read about this bass octave technique by Smith, and doesn't anybody else use it?

I'm going to have to look for my copy of his book. I'll get back to you.


It is actually a very cool idea - that of using the fundamental as a reference. There are a number of papers describing how we 'fill in', that is to say 'hear' the missing fundamental of a note.

We do this easily when listening to music on a tinny radio. We still hear the the low notes of the orchestra or piano as being 'low', even though the speaker can't produce useable sound below C3.

Top
#2362285 - Yesterday at 09:57 AM Re: Another check for the low bass-the 7th harmonic [Re: Mark Cerisano, RPT]
Kent Swafford Offline
Full Member

Registered: 06/06/07
Posts: 81
Loc: Kansas City
Please note that there are two editions of Virgil's book, and the two editions differ significantly.

Top
#2362297 - Yesterday at 10:53 AM Re: Another check for the low bass-the 7th harmonic [Re: prout]
rxd Offline
1000 Post Club Member

Registered: 03/11/09
Posts: 1801
Loc: London, England
Originally Posted By: prout
Originally Posted By: Mark Cerisano, RPT
I believe he advocated a "natural beat" at the fundamental of the lowest note. I read it in his book "New Techniques for Superior Aural Tuning", but that was a while ago.

If he didn't, that's how I understood it and that's one way I'm tuning bass octaves. I am very happy with result whereas before I wasn't. I rationalize that it may be a combination of all the neighbouring partials, which produce difference tones equal to the fundamental. (8-7=7-6=6-5=5-4=4-3=3-2=2-1=1, the natural beat).

I find it easier to hear when playing the octave loudly.

Surely someone must have this same experience.





The 'natural beat' you refer to sounds as if it is the 'resultant', a beat we hear that is produced by the brain, but is not actually measurable.

Obviously, with iH, 8-7 does not equal 7-6 nor any other difference of sequential partials. That only works with harmonics.

Given inharmonicity, the only way to tune the octave 'pure' using that technique, would be to tune the octave narrow, using the loudest set of sequential partials as a reference.

Edit reason: Attempt at improved clarity.

This is nearest to what I was going to say. Wasn't it Helmholtz who said these things were constructed in the ear?

There is another rationale for the appearance of the fundamental from short strings and small speakers and earpieces that cannot physically produce the fundamental. That is, very simply and ignoring iH; in a note with a frequency of 100 Hz., the second partial is 200hz., the 3rd, with elegant inevitability is 300Hz and so on. The difference tones between all the adjacent partials all have a frequency of 100hz. So, even though the string or speaker cannot produce 100Hz., it can produce many of the partials associated with 100Hz. and it is all those resultants that actually exist and are very real that we hear.

Bring In inharmonicity and the complex tone probably would have its own natural beat. I don't seem to hear any beat but I can't discount it either because it might just be the phenomenon that allows me to do what I described earlier. I just heard a live broadcast of a 7' I tuned that way this morning and specifically asked my girlfriend who has phenomenal hearing acuity if she heard the bass as sharp on my car radio speakers. Neither of us did.
_________________________
Concert & Recording tuner-tech, London, England.
"in theory, practice and theory are the same thing. In practice, they're not." - Lawrence P. 'Yogi' Berra.

Eschew obfuscation.



Top
#2362316 - Yesterday at 11:25 AM Re: Another check for the low bass-the 7th harmonic [Re: rxd]
prout Online   content
500 Post Club Member

Registered: 11/14/13
Posts: 898
Originally Posted By: rxd
Originally Posted By: prout
Originally Posted By: Mark Cerisano, RPT
I believe he advocated a "natural beat" at the fundamental of the lowest note. I read it in his book "New Techniques for Superior Aural Tuning", but that was a while ago.

If he didn't, that's how I understood it and that's one way I'm tuning bass octaves. I am very happy with result whereas before I wasn't. I rationalize that it may be a combination of all the neighbouring partials, which produce difference tones equal to the fundamental. (8-7=7-6=6-5=5-4=4-3=3-2=2-1=1, the natural beat).

I find it easier to hear when playing the octave loudly.

Surely someone must have this same experience.





The 'natural beat' you refer to sounds as if it is the 'resultant', a beat we hear that is produced by the brain, but is not actually measurable.

Obviously, with iH, 8-7 does not equal 7-6 nor any other difference of sequential partials. That only works with harmonics.

Given inharmonicity, the only way to tune the octave 'pure' using that technique, would be to tune the octave narrow, using the loudest set of sequential partials as a reference.

Edit reason: Attempt at improved clarity.

This is nearest to what I was going to say. wasn't it Helmholtz eh said these things were constructed in the ear
There is another rationale for the appearance of the fundamental from short strings and small speakers and earpieces that cannot physically produce the fundamental. That is, very simply and ignoring iH; in a note with a frequency of 100 Hz., the second partial is 200hz., the 3rd, with elegant inevitability is 300 and so on. The difference tones between all the adjacent partials all have a frequency of 100hz. So, even though the string of speaker cannot produce 100Hz., it can produce many of the partials associated with 100Hz. And it is all those resultants that actually exist that we hear. Bring In inharmonicity and the complex tone probably would have its own natural beat. I don't seem to hear any beat but I can't discount it either because it might just be the phenomenon that allows me to do what I described earlier. I just heard a live broadcast of a 7' I tuned that way this morning and specifically asked my girlfriend who has phenomenal hearing acuity if she heard the bass as sharp on my car radio speakers. Neither of us did.


The brain is capable doing precisely what you wrote above.

It is especially audible when playing M3s in the C5 and up range. We clearly hear the resultant P4 below, forming a second inversion Major triad. It hurts my ears when singers and flautists, working in any combination, produce M3s in that range.

Just so people understand that the resultant doesn't exist, I have recorded and analyzed M3s and there is no energy at any of the difference frequencies, only the partials of both notes, all above the first partials (obviously).

Top
#2362325 - Yesterday at 11:46 AM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
Mark Cerisano, RPT Offline
1000 Post Club Member

Registered: 01/24/10
Posts: 1483
Loc: Montreal, Quebec, Canada
I composed a piece of music in university using a synthesizer and lots of m2 and M2 up high. The resultant was very audible. The piece moved from playing the high small intervals, and then answering the resultant with the actual note played on the keyboard.

The other day, I was keenly aware, while playing a M3, of a low hum occurring at the fundamental of that series which contained the M3 I was playing. (5 - 4 = 1). I wasn't listening for it. I haven't ever thought it would be useful for tuning a piano, and I've never had and still don't have any interest in pursuing research in this area. I.e. I wasn't trying to hear it, it just popped out.

Nobody else has ever heard those resultant tones while tuning?
_________________________
Mark Cerisano, RPT
www.howtotunepianos.com

Top
#2362339 - Yesterday at 12:48 PM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
rxd Offline
1000 Post Club Member

Registered: 03/11/09
Posts: 1801
Loc: London, England
Yes, I hear them all the time. As trumpet players, we both hear them in a section bu particularly when only two instruments are playing. Beginning violinists are taught to hear the resultants when tuning their fifths.

This subject is currently on the UK pianopages. Some tuners readily admit to being puzzled by the whole thing.

As a teenageri was given a selection of old organ pipes. I connected two of them together on a piece of tubing and tuned them to get a resultant. This resultant was just as powerfull as the sounds from the two pipes. My trick, as a kid was to ask people which of the three notes were "real". Nobody ever said they couldn't hear three notes. In ET they are mostly too far off pitch to be of any use in tuning but I use M3's, fourths and fifths all the way up the treble into the sixth octave along with other checks so I hear them and ignore them all the time.

I consider it to be of absolutely no consequence where they come from but the fundamental can be heard coming from short bass strings. On the small uprite in my London flat they are very sonorous and easier to tune than they have any right to be.
_________________________
Concert & Recording tuner-tech, London, England.
"in theory, practice and theory are the same thing. In practice, they're not." - Lawrence P. 'Yogi' Berra.

Eschew obfuscation.



Top
#2362347 - Yesterday at 01:02 PM Re: Another check for the low bass-the 7th harmonic [Re: prout]
Mark Cerisano, RPT Offline
1000 Post Club Member

Registered: 01/24/10
Posts: 1483
Loc: Montreal, Quebec, Canada
Originally Posted By: prout


Just so people understand that the resultant doesn't exist, I have recorded and analyzed M3s and there is no energy at any of the difference frequencies, only the partials of both notes, all above the first partials (obviously).


Prout, I think I must have misunderstood you here. Are you saying resultant tones don't exist? Obviously they do or we wouldn't be able to hear beats, which are just really low resultant tones.

Here's a video I made showing how we can produce a major triad from only two notes.

Enjoy!

http://howtotunepianos.com/2014/12/16/resultant-tones/
_________________________
Mark Cerisano, RPT
www.howtotunepianos.com

Top
#2362378 - Yesterday at 02:27 PM Re: Another check for the low bass-the 7th harmonic [Re: Mark Cerisano, RPT]
prout Online   content
500 Post Club Member

Registered: 11/14/13
Posts: 898
Originally Posted By: Mark Cerisano, RPT
Originally Posted By: prout


Just so people understand that the resultant doesn't exist, I have recorded and analyzed M3s and there is no energy at any of the difference frequencies, only the partials of both notes, all above the first partials (obviously).


Prout, I think I must have misunderstood you here. Are you saying resultant tones don't exist? Obviously they do or we wouldn't be able to hear beats, which are just really low resultant tones.

Here's a video I made showing how we can produce a major triad from only two notes.

Enjoy!

http://howtotunepianos.com/2014/12/16/resultant-tones/


They exist as a result of your brain processing the TWO pitches. The third (resultant) does not exist as an acoustic phenomenon in the air and is not detectable by Fourier analysis. It is, nevertheless, 'real' and hurts my ears upon occasion.

In electronics, the difference frequency resulting from mixing two frequencies is an actual, measurable frequency. I know, I am building a Theremin this afternoon which mixes two frequencies of about 360kHz and produces an audible range of 20Hz to about 5KHz. I am seeing, as we speak, the resultant frequency on the oscilloscope.

Top
#2362464 - Yesterday at 06:49 PM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
Mark Cerisano, RPT Offline
1000 Post Club Member

Registered: 01/24/10
Posts: 1483
Loc: Montreal, Quebec, Canada
But if our ears hear it, i.e. the ear drum is moving in and out with a resultant component, then the microphone diaphragm will have the resultant component in it, and that should be picked up in a Fourier transform. I was able to apply a 100 Hz bandpass filter on the audio of my video and out came the 100hz sound. If it wasn't there, I couldn't filter it.

I feel you have a superior knowledge in this area but I would like to understand it a bit more.

Are you saying, if I take a 440 and 441hz signal and combine them, then filter out the 440 and 441 signal, the 1hz beat will not be there any more? It would make sense, but at the same time it seems to defy my common understanding.
_________________________
Mark Cerisano, RPT
www.howtotunepianos.com

Top
#2362489 - Yesterday at 07:51 PM Re: Another check for the low bass-the 7th harmonic [Re: Mark Cerisano, RPT]
prout Online   content
500 Post Club Member

Registered: 11/14/13
Posts: 898
Originally Posted By: Mark Cerisano, RPT
But if our ears hear it, i.e. the ear drum is moving in and out with a resultant component, then the microphone diaphragm will have the resultant component in it, and that should be picked up in a Fourier transform. I was able to apply a 100 Hz bandpass filter on the audio of my video and out came the 100hz sound. If it wasn't there, I couldn't filter it.

I feel you have a superior knowledge in this area but I would like to understand it a bit more.

Are you saying, if I take a 440 and 441hz signal and combine them, then filter out the 440 and 441 signal, the 1hz beat will not be there any more? It would make sense, but at the same time it seems to defy my common understanding.


There are a bunch of issues involved. The acoustic reproducers - speakers, headphones - introduce harmonic distortion that can produce the sounds you hear.

I will publish a wave-file and the Fourier transform that shows the non-existence of the clearly heard resultant. Give me a day or so.

I'm off to New York tomorrow. During the day I can find the papers that I mentioned earlier. They may help explain the phenomenon.

Cheers

Top
#2362524 - Yesterday at 10:15 PM Re: Another check for the low bass-the 7th harmonic [Re: Mark Cerisano, RPT]
DoelKees Offline
1000 Post Club Member

Registered: 05/01/10
Posts: 1766
Loc: Vancouver, Canada
Originally Posted By: Mark Cerisano, RPT
But if our ears hear it, i.e. the ear drum is moving in and out with a resultant component, then the microphone diaphragm will have the resultant component in it, and that should be picked up in a Fourier transform. I was able to apply a 100 Hz bandpass filter on the audio of my video and out came the 100hz sound. If it wasn't there, I couldn't filter it.

I feel you have a superior knowledge in this area but I would like to understand it a bit more.

Are you saying, if I take a 440 and 441hz signal and combine them, then filter out the 440 and 441 signal, the 1hz beat will not be there any more? It would make sense, but at the same time it seems to defy my common understanding.


Try mixing a 400Hz sine wave and a 300Hz and do a spectral analysis. You will not see the difference tone at 100Hz. Beats are not pressure waves, though they both are measured in Hz! Same for 440 and 441 of course.

Feed the 400+300 sound to a non-linear distortion device and record the result and you will see the difference tone (beat) in the Fourier analysis.

Your ear+brain is non-linear.

Kees

Top
#2362528 - Yesterday at 10:26 PM Re: Another check for the low bass-the 7th harmonic [Re: GMG]
prout Online   content
500 Post Club Member

Registered: 11/14/13
Posts: 898
Here is a view of the partials of a M3. The wave-file can be heard here - M3 resultant

You can hear the resultant, using headphones, starting at about 2 seconds into the recording. The resultant is at 66.6309Hz, but does not show up in the Fourier Analysis screen. The beats you hear (3.0bps, Young temperament) is the beating of the 5th and 4th partials.



The analysis screen shows power line artifacts at 60 and 120Hz. They can be ignored.


Edited by prout (Yesterday at 10:32 PM)

Top
#2362861 - Today at 03:59 PM Re: Another check for the low bass-the 7th harmonic [Re: DoelKees]
prout Online   content
500 Post Club Member

Registered: 11/14/13
Posts: 898
Originally Posted By: DoelKees
Originally Posted By: Mark Cerisano, RPT
But if our ears hear it, i.e. the ear drum is moving in and out with a resultant component, then the microphone diaphragm will have the resultant component in it, and that should be picked up in a Fourier transform. I was able to apply a 100 Hz bandpass filter on the audio of my video and out came the 100hz sound. If it wasn't there, I couldn't filter it.

I feel you have a superior knowledge in this area but I would like to understand it a bit more.

Are you saying, if I take a 440 and 441hz signal and combine them, then filter out the 440 and 441 signal, the 1hz beat will not be there any more? It would make sense, but at the same time it seems to defy my common understanding.


Try mixing a 400Hz sine wave and a 300Hz and do a spectral analysis. You will not see the difference tone at 100Hz. Beats are not pressure waves, though they both are measured in Hz! Same for 440 and 441 of course.

Feed the 400+300 sound to a non-linear distortion device and record the result and you will see the difference tone (beat) in the Fourier analysis.

Your ear+brain is non-linear.

Kees


As Kees has stated above, the ear+brain is non linear.

Here is an analysis of two tones down mixed to a single channel and played simultaneously. As you can see, only two frequencies are detected - 660Hz and 825Hz.

Listen to the wave file.

660-825Hz test

Depending on your equipment/ears/brain, you will hear at least four pitches - 660Hz, 825Hz, 165Hz (825-660), and 495Hz (660-165). It may be possible to detect 330Hz as well (495-165).

Prout

(p.s. - The wave file was recorded with 660Hz in the left channel and 825Hz in the right channel. If you open the file in Audacity and mute one channel or pan the volume fully left or right, the effect will disappear.)


Top
#2362863 - 54 minutes 18 seconds ago Re: Another check for the low bass-the 7th harmonic [Re: GMG]
pyropaul Online   content
Full Member

Registered: 11/16/10
Posts: 194
Loc: Montreal
I hear only two tones, one in the left ear and one in the right. If I mix it down to mono, or play it on my computer's speakers and don't sit very close, then I hear the sum and difference tones. It is the ear drums that are the non-linear element where the mixing takes place, not the brain.

Paul.

Top
#2362871 - 46 minutes 57 seconds ago Re: Another check for the low bass-the 7th harmonic [Re: prout]
prout Online   content
500 Post Club Member

Registered: 11/14/13
Posts: 898
Originally Posted By: prout
Originally Posted By: Mark Cerisano, RPT
But if our ears hear it, i.e. the ear drum is moving in and out with a resultant component, then the microphone diaphragm will have the resultant component in it, and that should be picked up in a Fourier transform. I was able to apply a 100 Hz bandpass filter on the audio of my video and out came the 100hz sound. If it wasn't there, I couldn't filter it.

I feel you have a superior knowledge in this area but I would like to understand it a bit more.

Are you saying, if I take a 440 and 441hz signal and combine them, then filter out the 440 and 441 signal, the 1hz beat will not be there any more? It would make sense, but at the same time it seems to defy my common understanding.


There are a bunch of issues involved. The acoustic reproducers - speakers, headphones - introduce harmonic distortion that can produce the sounds you hear.

I will publish a wave-file and the Fourier transform that shows the non-existence of the clearly heard resultant. Give me a day or so.

I'm off to New York tomorrow. During the day I can find the papers that I mentioned earlier. They may help explain the phenomenon.

Cheers


Try this site or just Google "missing fundamentals"

http://auditoryneuroscience.com/topics/missing-fundamental

Top

Moderator:  Piano World 
What's Hot!!
Christmas Header
- > Gift Ideas for Music Lovers < -
From PianoSupplies.com a division of Piano World.
-------------------
The December Free Piano Newsletter
-------------------
Forums Rules & Help
-------------------
ADVERTISE
on Piano World

The world's most popular piano web site.
-------------------
PIANO BOOKS
Interesting books about the piano, pianists, piano history, biographies, memoirs and more!
(ad) Yamaha CP Music Rest Promo
Yamaha CP Music Rest Promo
(ad) HAILUN Pianos
Hailun Pianos - Click for More
Ad (Seiler/Knabe)
Seiler Pianos
(125ad) Dampp Chaser
Dampp Chaser Piano Life Saver
(ad) Lindeblad Piano
Lindeblad Piano Restoration
(ad) Piano Music Sale - Dover Publications
Piano Music Sale
Sheet Music Plus (125)
Sheet Music Plus Featured Sale
New Topics - Multiple Forums
Good Practice Amp for Roland FP7F?
by TheloniousPunk
12/17/14 04:24 PM
Kawai
by daz100
12/17/14 04:10 PM
New at the forum and some questions
by Kua
12/17/14 03:31 PM
It's Beethoven's birthday today...
by Polyphonist
12/17/14 03:12 PM
Elbow pain
by acollins
12/17/14 12:49 PM
Forum Stats
77325 Members
42 Forums
159942 Topics
2348826 Posts

Max Online: 15252 @ 03/21/10 11:39 PM
Gift Ideas for Music Lovers!
Find the Perfect Gift for the Music Lovers on your List!
Visit our online store today.

Visit our online store for gifts for music lovers

 
Help keep the forums up and running with a donation, any amount is appreciated!
Or by becoming a Subscribing member! Thank-you.
Donate   Subscribe
 
Our Piano Related Classified Ads
|
Dealers | Tuners | Lessons | Movers | Restorations | Pianos For Sale | Sell Your Piano |

Advertise on Piano World
| Subscribe | Piano World | PianoSupplies.com | Advertise on Piano World | Donate | Link to Us | Classifieds |
| |Contact | Privacy | Legal | About Us | Site Map | Free Newsletter | Press Room |


copyright 1997 - 2014 Piano World ® all rights reserved
No part of this site may be reproduced without prior written permission