plans/ schematic for a guitar/ instrument string sustaining

[Allan Herriman]

On Wed, 27 Oct 2004 13:21:28 GMT, "Kevin Aylward"
<salesEXTRACT@anasoft.co.uk> wrote:

Allan Herriman wrote:
On 27 Oct 2004 09:21:17 GMT, chrisgibbogibson@aol.com
(ChrisGibboGibson) wrote:

(Ronald H. Nicholson Jr.) wrote:


In article <251020040117453752%justin.c@se.net>,
justin <justi nüc@se.net> wrote:
It is
well known to me that string frequency will vary over the duration
of a note because of a nonlinear mechanics of a string. After all,
if it wasn't for that - a string would be unusable. But this side
effect anomaly is so subtle and irrelevant to a musician ...

Not necessarily true. Ask a musician to play a piano that is
perfectly tuned in equal temperament, rather than "stretch" tuned,
as is usually done to take into account these real physical and
inharmonic effects, and they might think the piano is unpleasantly
out-of-tune. Makes it quite relevant.


"Stretch tuning" and "equal temperament" have *nothing* to do with
the phenomena of a string changing pitch throughout the duration of
the note and dependant upon how hard it is plucked or hit.

Equal temperament tuning means quite simply that all semitone
intervals on the keyboard are an equal fraction up on the previous
note and all octaves are exactly double the frequency of the next
lower octave.

Stretch tuning is where the top of the keyboard is deliberately made
sharp with respect to the centre and the lower part of the keyboard
is deliberately made flat.

This is to compensate for the way the human ear perceives tone. ie
although 4000 Hz is exacty 2 octaves above 1000Hz the human ear will
perceive it as being flat.

Oh. I thought it was because the harmonics of a real, physical
instrument aren't exactly at integer multiples of the frequency of the
fundamental - they're a little sharp.
So you make the low notes a little flat, so that their harmonics are
in tune with the middle notes, and you make the high notes a little
sharp, so that they're in tune with the harmonics of the middle notes.

This may be completely wrong.


Some true facts, but unlikely, imo, to be the reason for tuning
stretching. This would suggest that the ear is more sensitive to lower
level harmonics then the main dominant frequency. Why would the
fundamental not sound out of tune, its much larger?

I found this web site:
http://www.harpcolumn.com/bboard/q-and-a-fetch-msg.tcl?msg_id=0000yn

which contained this quote:

"Stretching means you tune it slightly greater than an octave so the
"beats" disappear in the octaves. This is because the strings will
never be able to beat perfectly mathematically because of the physical
attributes, such as the thickness and length of the string, etc."


I assume that these beats come from some non-linear processing - in
the ear or brain. I thought this happened after the frequency
selectivity, though. Would this indicate that the harmonics of the
lower note are mixing with the fundamental of the higher note?

Regards,
Allan

 

[Kevin Aylward]

ChrisGibboGibson wrote:

"Dan" wrote:

[snip]

Or better yet, a fretboard build into the body and use a compressor
and better pickups. How do you think Carlos gets his sustain?


By distorting the shit out of it so it no longer sounds like a
guitar. Which I suppose does have the advantage that it helps hide
the fact that he plays like somone broke his fingers.

Living on a reputation. That he never earned anyway.

Well, I wouldnt go that far. Carlos plays some tunefull stuff. Now if
you were talking about Eric Crapton, I would agree.

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[ChrisGibboGibson]

"Kevin Aylward" wrote:

ChrisGibboGibson wrote:
"Dan" wrote:

[snip]

Or better yet, a fretboard build into the body and use a compressor
and better pickups. How do you think Carlos gets his sustain?


By distorting the shit out of it so it no longer sounds like a
guitar. Which I suppose does have the advantage that it helps hide
the fact that he plays like somone broke his fingers.

Living on a reputation. That he never earned anyway.


Well, I wouldnt go that far. Carlos plays some tunefull stuff.

Yeah, tuneful stuff, just badly played.

Now if
you were talking about Eric Crapton, I would agree.

What was his old nickname? Clubhand?

Gibbo

 

[Clifford Heath]

Kevin Aylward wrote:

behavior of the string is surprisingly strongly affected by the
mechanical impedance and frequency response of the guitar as a
whole,
This makes an either very badly formulated or simply _not true_
statement.
Yep. The statement is fundamentally wrong.

The statement was carefully formulated so it cannot be claimed
to be right or wrong. But perhaps you've done a convincing empirical
study of the degree of surprise in subjects when they're told of
the actual magnitude of the effect?

Just bug off Aylward, you're out of line.

 

[Rich Grise]

On Wed, 27 Oct 2004 04:44:12 +0000, Ronald H. Nicholson Jr. wrote:

In article <251020040117453752%justin.c@se.net>,
justin <justi nüc@se.net> wrote:
It is
well known to me that string frequency will vary over the duration of a
note because of a nonlinear mechanics of a string. After all, if it
wasn't for that - a string would be unusable. But this side effect
anomaly is so subtle and irrelevant to a musician ...

Not necessarily true. Ask a musician to play a piano that is perfectly
tuned in equal temperament, rather than "stretch" tuned, as is usually
done to take into account these real physical and inharmonic effects,
and they might think the piano is unpleasantly out-of-tune. Makes it
quite relevant.

Well, unless your piano is preternaturally stable, avoid a piano tuner
named "Oppernockity".

Oppernockity only tunes once.

Cheers!
Rich

 

[Rich Grise]

On Wed, 27 Oct 2004 09:21:17 +0000, ChrisGibboGibson wrote:

This is to compensate for the way the human ear perceives tone. ie
although 4000 Hz is exacty 2 octaves above 1000Hz the human ear will
perceive it as being flat.

Where do you get this crap?

 

[Clifford Heath]

ChrisGibboGibson wrote:

Stretch tuning is where the top of the keyboard is deliberately made sharp with
respect to the centre and the lower part of the keyboard is deliberately made
flat.

This is to compensate for the way the human ear perceives tone. ie although
4000 Hz is exacty 2 octaves above 1000Hz the human ear will perceive it as
being flat.

Not quite. The problem is that a string at say 500Hz will have a 2nd
harmonic slightly above 1000Hz (say 1000.N Hz), a 3rd even further
above 1500, etc. The effect is due mostly to end effects, as it
varies with the gauge (stiffness/mass ratio) of the string itself.
The ear hears many of the harmonics and "blends" them, so when you play
a 1000.N Hz note over the previous, the ear hears that the fundamental
agrees with the 2nd harmonic, but now the new note's 2nd harmonic is
flat wrt the original's 4th. Some folk notice that, some don't.

So depending on the individual's preferences and hearing, some will
still hear the octave as flat *even though it's stretched*. The effect
is quite noticable to a trained ear. A friend who's a prominent keyboard
teacher and performer likes his pianos stretched *two full semitones*
across the range. It's a matter of preference as to how much to stretch.

Clifford Heath.

 

[ChrisGibboGibson]

"Sam Waterston" wrote:

On Sat, 23 Oct 2004 18:10:04 +0000, ChrisGibboGibson wrote:

"Sam Waterston" wrote:

I'm trying to locate a schematic for a circuit that allows a sustained
resonance of guitar or instrument strings. There is already such a
device called an Ebow, found here:

http://www.ebow.com/ebow/brochure.htm

However, this unit doesn't allow the oscillator to be varied, and I'd
like to vary the string frequency this way.


Varying the frequency of the e-bow will not vary the frequency of the
string so the note will remain the same. The tonality will change though.

You have to appreciate how the e-bow works. It is *not* a feedback device.
It's a very fast, very mild plucking device. It's more like *very* quickly
plucking the string with a *very* soft plectrum.

It effectively, magnetically, gives the string a lil gentle thump at a
lowish frequency.

Thank you. I didn't know this - I just assumed it was all the parts of a
tuning fork oscillator except the fork, which would be the string.

Are they normally variable,

No you have to pull it apart.

or is it _so_ sharp that any variation
makes it sound worse? 'cause you could spread out a pot to cover, say,
+- 3Hz or something.

3Hz wouldn't make much difference. It's a case of getting a balance between
physically strumming a string too fast (which introduces it's own note) or too
slow (which just sounds like strumming a string really fast).

Back to....

Thank you. I didn't know this - I just
assumed it was all the parts of a
tuning fork oscillator except the fork,
which would be the string.

Yes you're right the earlier e-bows were an oscillator that used the string as
the resonant element (actually the very first ones were purely mechanical but I
think they were sold under a different name). This causes problems when bands
start playing at horrendous volumes (obviously quite common) and also they're
difficult to control. The later ones use a gated oscillator and are much easier
to control and less susceptible to outside interference.

I have just been informed that the resonant ones are still available but they
now have cross lined lasers to align them perfectly over the string. How much
trouble will people go to in order to get a sound? !!!

Gibbo

 

[Kevin Aylward]

Rich Grise wrote:

On Wed, 27 Oct 2004 04:44:12 +0000, Ronald H. Nicholson Jr. wrote:

In article <251020040117453752%justin.c@se.net>,
justin <justi nüc@se.net> wrote:
It is
well known to me that string frequency will vary over the duration
of a note because of a nonlinear mechanics of a string. After all,
if it wasn't for that - a string would be unusable. But this side
effect anomaly is so subtle and irrelevant to a musician ...

Not necessarily true. Ask a musician to play a piano that is
perfectly tuned in equal temperament, rather than "stretch" tuned,
as is usually done to take into account these real physical and
inharmonic effects, and they might think the piano is unpleasantly
out-of-tune. Makes it quite relevant.

I think you got this upside-down. The "tempered" scale, which is used
on pianos these days, was invented to avoid the effects that you note,

No it wasn't. Equal temperament has nothing whatsoever to do with side
effects of string mechanics. It was invented to avoid a fundamental 1st
order problem.

which show up when you try to transpose a piece that's written on
a truly diatonic/harmonic scale.

Yes.

Equal temperament was invented to allow for instruments to be played in
any key and with other instruments and essentially sound the same.

However, this does highlight one of my pet peeves. You often get those
pretentious dudes using harmonics to tune to. That is, tuning the
harmonic at the 5th fret to the harmonic on the next string at the 7th
fret. This is wrong as the notes are not the same, only close in equal
temperament tuning. Try as one might, one can't convince them otherwise.
Unfortunately most guitar players are as thick as a plank of wood.

i.e. a major third, a minor third, and a major fourth don't add up to
an octave, so they bend them _all._

All 5ths are flattened. You can manually tune a piano by doing a "circle
of 5ths". That is you start at one note and tune the 5th above by
measuring the time between (harmonic) beats (3-15 bps). You can
construct a beat table from the knowledge that each semitone is the
twelfth root of 2 times the next. You usually try and remain in the same
octave, so the 5th above might be played an octave lower. So, a so
called "perfect 5th" isn't.

I used to tune organs that way when I was 16. I use to wait for the TV
test card as it outputed an A at 440Hz.


Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Kevin Aylward]

Rich Grise wrote:

On Wed, 27 Oct 2004 13:23:32 +0000, Kevin Aylward wrote:

Rich Grise wrote:

I'd submit that the frequency will be measurably different from an
acoustic than from a string with the exact same bridge and nut, and
exact same tension, mounted on a marble base, because the the top of
the guitar will be part of the resonating mass.

And your submission would be wrong. The resonating mass has nothing
to do with the problem.

Then, apparently, you and I are looking at different "problems". The
point of my post was simply that a string on a marble base _with the
same tenion_ will resonate at a different frequency than if it's
mounted on a base that can vibrate along with it, because there's
different stuff vibrating.

Now your weaselling out. Of course, if the ends of the string are not
fixed the frequency will change. For any credible and usable guitar the
nut and bridge are fixed, by design.

Lord, deliver me from linear thinkers.

Some of us have actually done this "vibrating
string" problem in formal courses. Sure, there are a few minor
subtleties, but as I already stated, the frequency of the string is
essentially determined by the mass per unit length and the tension. A
^^^^^^^^^^^^^^^^^^^^

Which is different for a compliant mounting, was my point.

The mass per unit length is the mass per unit length of the *string*,
not the guitar!

The basic assumption here is that the guitar has been made correctly.
The initial post was about varying the frequency of the string in some
fundamental way. Nothing has changed. This cant be done. All of this
extra stuff is flogging a dead horse. Sure, 2nd order effects might come
in, but that is not relevant to the basic point.

point on the string goes up and down with acceleration force =
dl.rho.d^2y/dx^2, the tension can be resolved into x and y planes
etc...all from memory...

The obvious subtlety is that the tension changes a little as the
string moves, so this changes the frequency a little, but this is
very minor. If it were too drastic, guitars would sound out of tune
when hit hard. They don't.

You'd be surprised. ;-)

All I was saying is that there's more to the experiment than first
meets the eye. The "STRING" is the same, but the "MOUNTING" is
different. This can affect the resonant frequency of the "SYSTEM"

In principle, in general systems, yes. In this particular case, not that
it matters.

Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Kevin Aylward]

ChrisGibboGibson wrote:

"Kevin Aylward" wrote:

[snip]

The obvious subtlety is that the tension changes a little as the
string moves, so this changes the frequency a little, but this is
very minor. If it were too drastic, guitars would sound out of tune
when hit hard. They don't.


They do if you put poof gauge strings on like .008 s

Not at all. I presume this is in referance to my standard use of a 0.007
set? e.g.

0.007, 0.009, 0.011, 0.016 (wound), 0.022, 0.028.

Stays in tune and I haven't broke a string for 30 years. I also don't
have calluses as the string action is also extremly low. Just skims
above the frets.


Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[ChrisGibboGibson]

Rich Grise wrote:

On Wed, 27 Oct 2004 09:21:17 +0000, ChrisGibboGibson wrote:

This is to compensate for the way the human ear perceives tone. ie
although 4000 Hz is exacty 2 octaves above 1000Hz the human ear will
perceive it as being flat.

Where do you get this crap?

Yamaha, Roland, Korg, oh and 30 years as a musician.

I posted a link to Roland's website where it tells you what stretch tuning is
for.

It isn't crap Rich. It's fact. Just because *you* didn't know it doesn't make
it crap.

Gibbo

 

[ChrisGibboGibson]

"Kevin Aylward" wrote:

ChrisGibboGibson wrote:
"Kevin Aylward" wrote:

[snip]

The obvious subtlety is that the tension changes a little as the
string moves, so this changes the frequency a little, but this is
very minor. If it were too drastic, guitars would sound out of tune
when hit hard. They don't.


They do if you put poof gauge strings on like .008 s


Not at all. I presume this is in referance to my standard use of a 0.007
set? e.g.

No. I didn't know what you used.

0.007, 0.009, 0.011, 0.016 (wound), 0.022, 0.028.

Stays in tune and I haven't broke a string for 30 years. I also don't
have calluses as the string action is also extremly low. Just skims
above the frets.

Well I use 11 to 48 on 25 1/2" scale and 12 to 56 on 24 3/4" scale.

I do know that when I play other guitars with 8s on them, and hit the bass
strings *very* hard there is a distinct change in pitch as the note decays.

Gibbo

 

[Rich Grise]

On Thu, 28 Oct 2004 10:19:54 +0000, ChrisGibboGibson wrote:

Rich Grise wrote:

On Wed, 27 Oct 2004 09:21:17 +0000, ChrisGibboGibson wrote:

This is to compensate for the way the human ear perceives tone. ie
although 4000 Hz is exacty 2 octaves above 1000Hz the human ear will
perceive it as being flat.

Where do you get this crap?


Yamaha, Roland, Korg, oh and 30 years as a musician.

I posted a link to Roland's website where it tells you what stretch tuning is
for.

It isn't crap Rich. It's fact. Just because *you* didn't know it doesn't make
it crap.

Well, I do know that 4000 Hz is exactly two octaves from 1000 Hz. And

they've always sounded like octaves to me.

Sorry.
Rich

 

[ChrisGibboGibson]

Rich Grise wrote:

On Thu, 28 Oct 2004 10:19:54 +0000, ChrisGibboGibson wrote:

Rich Grise wrote:

On Wed, 27 Oct 2004 09:21:17 +0000, ChrisGibboGibson wrote:

This is to compensate for the way the human ear perceives tone. ie
although 4000 Hz is exacty 2 octaves above 1000Hz the human ear will
perceive it as being flat.

Where do you get this crap?


Yamaha, Roland, Korg, oh and 30 years as a musician.

I posted a link to Roland's website where it tells you what stretch tuning
is
for.

It isn't crap Rich. It's fact. Just because *you* didn't know it doesn't
make
it crap.

Well, I do know that 4000 Hz is exactly two octaves from 1000 Hz. And
they've always sounded like octaves to me.

I guess this crew are also taking crap then.....

http://www.lafavre.us/tuning-marimba.htm

<QUOTE>

Unfortunately, we are not finished yet with the details! Apparently, human
hearing is a bit quirky. We tend to hear high notes a bit flat. To compensate
for this, an instrument with a wide compass can be tuned with the high notes
slightly sharp.

</QUOTE>

http://www-math.cudenver.edu/~jstarret/tuninghist.html

<QUOTE>

In practice, even equally tempered instruments, such as the piano, sound flat
in their upper octaves when they are tuned in strict accordance with the equal
tempered scale. Piano-tuners employ a trick called, 'brightening the treble' or
'stretch tuning', which means that the top one and a half to two octaves are
sharpened slightly; the low bass octaves are also lowered in a similar fashion.

The need for this technique seems to arise partly from anomalies with our aural
perception at high and low frequencies and partly with mechanical inadequacies
in the piano itself; outside of the range 64 Hz to 4100 Hz, we lose our ability
to distinguish intervals correctly.

</QUOTE>

http://www.rolandus.com/glossary_main.asp

<QUOTE>

Stretch tuning
Traditional acoustic piano tuning that slightly sharpens the highest keys and
slightly flattens the lowest keys for psychoacoustic purposes.

</QUOTE>

http://www.nzmusician.co.nz/index.php/ps_pagename/printversion/pi_articleid/299

<QUOTE>

To make high and low notes on the same instrument sound good when played
together, they would 'stretch' the overall tuning - making bass-end notes a
little flat, and high-end notes a little sharp.

Partly, this is due to string imperfections, and partly... because the human
ear seems to like it that way! (Neuroscientists are still trying to explain
why.) Even the tuned percussion bars used in junior schools need their tuning
tweaked by a few cents, for notes above or below the middle octave.

</QUOTE>

Maybe the whole world's talking crap. Which I have often wondered sometimes.



Gibbo

 

[Kevin Aylward]

ChrisGibboGibson wrote:

Rich Grise wrote:

On Thu, 28 Oct 2004 10:19:54 +0000, ChrisGibboGibson wrote:

Rich Grise wrote:

On Wed, 27 Oct 2004 09:21:17 +0000, ChrisGibboGibson wrote:

This is to compensate for the way the human ear perceives tone. ie
although 4000 Hz is exacty 2 octaves above 1000Hz the human ear
will perceive it as being flat.

Where do you get this crap?


Yamaha, Roland, Korg, oh and 30 years as a musician.

I posted a link to Roland's website where it tells you what stretch
tuning
is
for.

It isn't crap Rich. It's fact. Just because *you* didn't know it
doesn't
make
it crap.

Well, I do know that 4000 Hz is exactly two octaves from 1000 Hz. And
they've always sounded like octaves to me.


I guess this crew are also taking crap then.....

http://www.lafavre.us/tuning-marimba.htm

QUOTE

Unfortunately, we are not finished yet with the details! Apparently,
human hearing is a bit quirky. We tend to hear high notes a bit flat.
To compensate for this, an instrument with a wide compass can be
tuned with the high notes slightly sharp.



To make high and low notes on the same instrument sound good when
played together, they would 'stretch' the overall tuning - making
bass-end notes a little flat, and high-end notes a little sharp.

Partly, this is due to string imperfections, and partly... because
the human ear seems to like it that way! (Neuroscientists are still
trying to explain why.)
Even the tuned percussion bars used in junior
schools need their tuning tweaked by a few cents, for notes above or
below the middle octave.

/QUOTE

Well I will disagree with "need". Sure, this is a well known effect, but
today, its pretty much irrelevant. Essentially this stretch tuning is
never done with modern instruments. Its hard to say just what the ratio
is of real piano verses PCM synth piano is, but I'd wager that its 99.9%
electronic nowadays. Sure, modern keyboard can often be set to have many
different tunings (digitally) but the reality is that no one does it,
and no one notices. One should note that the piano is being played with
other instruments, so having its tuning slightly off when others are not
will cause a problem.


Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.

 

[Kevin Aylward]

Allan Herriman wrote:

On 27 Oct 2004 09:21:17 GMT, chrisgibbogibson@aol.com
(ChrisGibboGibson) wrote:

(Ronald H. Nicholson Jr.) wrote:


In article <251020040117453752%justin.c@se.net>,
justin <justi nüc@se.net> wrote:
It is
well known to me that string frequency will vary over the duration
of a note because of a nonlinear mechanics of a string. After all,
if it wasn't for that - a string would be unusable. But this side
effect anomaly is so subtle and irrelevant to a musician ...

Not necessarily true. Ask a musician to play a piano that is
perfectly tuned in equal temperament, rather than "stretch" tuned,
as is usually done to take into account these real physical and
inharmonic effects, and they might think the piano is unpleasantly
out-of-tune. Makes it quite relevant.


"Stretch tuning" and "equal temperament" have *nothing* to do with
the phenomena of a string changing pitch throughout the duration of
the note and dependant upon how hard it is plucked or hit.

Equal temperament tuning means quite simply that all semitone
intervals on the keyboard are an equal fraction up on the previous
note and all octaves are exactly double the frequency of the next
lower octave.

Stretch tuning is where the top of the keyboard is deliberately made
sharp with respect to the centre and the lower part of the keyboard
is deliberately made flat.

This is to compensate for the way the human ear perceives tone. ie
although 4000 Hz is exacty 2 octaves above 1000Hz the human ear will
perceive it as being flat.

Oh. I thought it was because the harmonics of a real, physical
instrument aren't exactly at integer multiples of the frequency of the
fundamental - they're a little sharp.
So you make the low notes a little flat, so that their harmonics are
in tune with the middle notes, and you make the high notes a little
sharp, so that they're in tune with the harmonics of the middle notes.

This may be completely wrong.

Some true facts, but unlikely, imo, to be the reason for tuning
stretching. This would suggest that the ear is more sensitive to lower
level harmonics then the main dominant frequency. Why would the
fundamental not sound out of tune, its much larger?


Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.