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Tuning Precision & Accuracy

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#1 d.elliott

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Posted 14 March 2014 - 07:10 PM

Once upon a time, the accuracy and precision of tuning was all done by ear. I think we can all agree on this.

 

The accuracy was determined by the accuracy of tuning forks and how that was transferred to master reed sets. The precision or repeatability of a tuning being down to the skill and ear of the tuner.

 

When I first started in this game, I tried different meters, and looked for accuracy and repeatability in readings, I also looked at discrimination of displayed values, so if I was trying to tune to say +/- 5 cents, I needed to be able to measure at least 1/5th of the spread of the tolerance preferably 1/10th of the spread, or 1 cent in this case.

 

So,  Accuracy is in the actual value of the nominal value being achieved, assuming the meter shows no error for the note in question.So if the meter says  A= 440 Hz, it is  440 Hz not 441, or 442 Hz).

 

Precision = how close the the tuning technique, my skill and the repeatability of the meter allows me to get to the shown A= 440 Hz over, say 20 different occasions. 

 

All this is why engineers talk in tolerances.

 

My next quest was to establish my own tuning tolerance standard, assuming an accurate measurement and a repeatable meter which would allow me read with an appropriate level of discrimination. I read-up various medical and musical papers and came upon the statement that most people can determine an error of 5 cents between two 'same' notes, some can say which of two notes is sharp or flat to the other, many cannot. I was taken be the statement that people can hear a dime fall. I took me quite some time to realise that a dime was 5 cents, but we don't have dimes in Yorkshire. This 5 cents detection was hearing two continuous notes, I reasoned that musical notes are transitory, a MM of 60 beats would give each note 1 second if playing crotchets, 1/2 a second if playing quavers, clearly MM 120  halves all this again, So +/- 2.5 cents seamed reasonable, say +/- 2 cents to allow for drift etc.

 

Playing 3rds. 5ths & octaves I re-evaluated this to my current standard of +/- 1.5 cents from nominal across the range. The only exceptions being at a player's request or if a low pitched reed on an Anglo which can sometimes bend to flat when played above mp.

 

I raise this topic as a result of working on two  instruments for a certain player who could determine errors of less than 1 cent, by ear, and tell which note is the sharper of two , all this on an Anglo. The best I could manage was +/- 0.5 cents using a discrimination of 0.1 cents, and an instrumentation discrimination of probably 0.01 cents.

 

Whilst I am quite happy to work to +/- 1.5 cents from nominal, and my various customers and players (except 1) are also happy with this, I wonder what tolerance other repairers are using. I will add that I get instruments brought to me for tuning tweaks that have been known (or reported) to have been serviced, tuned, repaired by others or before acquisition that can have several 5 cents or more variations from nominal. Some probably as a result of drift, but much as a result of rushed and sloppy workmanship. I can understand an inaccurately tuned instrument, say all  notes 3 cents sharp, or say 2 cents flat, but not a wide spread in the overall precision of tuning.

 

It would be good to determine an agreed standard, to protect players provide a control standard to repairers and guide home restorers alike. 

 

So I have declared my standard, what does the rest of the world do?

 

Dave

 

 



#2 Don Taylor

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Posted 14 March 2014 - 07:38 PM

Dave:

 

FWIW (not much).  A dime is 10 cents, and a nickel is 5.

 

Don.



#3 Stephen Chambers

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Posted 14 March 2014 - 07:51 PM

Dave:

 

FWIW (not much).  A dime is 10 cents, and a nickel is 5.

 

So that's your "ten cents worth"... ;)



#4 Stephen Chambers

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Posted 14 March 2014 - 08:01 PM

Dave,

 

When I'm fine-tuning a concertina, I only accept results that are 0 or +1, but I'll try to improve on anything else - though we both know the difficulties and contradictory results that can ensue. But the penultimate measure is if it sounds acceptable to my ear, and the final one is if it sounds acceptable to the player - and sometimes they might bend a note more, or less, than myself.

 

I'd suspect that many of the "sloppy" tunings you mention are the result of people only "rough-tuning" a box, and not even attempting any "fine-tuning".



#5 Doug Barr

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Posted 14 March 2014 - 10:56 PM

Dave,

 

With all due respect, some of the things you said scare me.  I fortunately or unfortunately am very sensitive to tuning issues.  This statement really bothers me:

 

"This 5 cents detection was hearing two continuous notes, I reasoned that musical notes are transitory, a MM of 60 beats would give each note 1 second if playing crotchets, 1/2 a second if playing quavers, clearly MM 120  halves all this again, So +/- 2.5 cents seamed reasonable, say +/- 2 cents to allow for drift etc."

 

Reminds me of an old music joke: If you play fast the mistakes don't last as long.

 

I would think that you would want to do the best job you are capable of on each instrument regardless of whether or not the customer can hear the difference, i'm sure you can tell the difference!  What about the other musicians that listen to this instrument and might or might not want to know who tuned it!

 

I've tried my hand at tuning, and know it can be difficult, time consuming, and a PITA, but that is why I would send an instument to a proffesonal, not just a "repairer"

 

Not to sure I would be happy with your "tolerances"

 

I think it would be good to determine an agreed standard, to protect players. How about +/- 0

 

Sorry but your post moved me to respond,  I mean no disrespect.

 

Doug

 



#6 Terry McGee

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Posted 15 March 2014 - 01:27 AM

Doug's proposed +/- 0 reminds me of the old Cornish tin-worker.  When asked to what tolerances they worked, he responded: "We don't work to no tolerances!  We gets it right, and then it's near enough"!

 

Problem with specifying +/-0 though is how many decimal places are you prepared to take your zero?  Is +/- 0.1 cents good enough, or +/- 0.01 cents, or 0.001 cents.  There really isn't such a thing as zero.

 

I think Dave has really thought through the issues very well here, and it's a challenge to us to shake his faith in his assumptions.  I'm imagining, Dave, that either you're using a strobe type tuner that could get below the thickness of the needle in the analogue style tuner, or you're aware of them.  Strobe tuners can get down to around 0.01 cents precision, with typically 0.1cents or better accuracy, so we're certainly not limited by measurement precision.  We need to look at what other limitations we need to work within.

 

I'd imagine, following Doug's exhortation to get it right, that a limitation could be budgetary.  The quest for precision typically follows the Law of Diminishing Returns - it probably costs you a lot more time and patience to get from +/- 10 cents to +/- 1 cent than it did to get from +/- 100 cents to +/- 10cents.  It's not so much Dave's preparedness to slog on that's in question here, it's whether his customers are prepared to pay for it.  Paying for precision you can't hear doesn't make a lot of sense.

 

Another limitation we would need to consider is technical.  How long will the instrument keep its tuning?  No point in slogging on to within +/-0.1 cents if it will be outside that range by the time it reaches the customer, or whenever the temperature changes by 5º or the humidity by 10%, or after 10 minutes of normal playing.  And will it change linearly across the instrument or do big reeds change at a different rate to short ones?  Do we even have this information?

 

So, my initial impression is that Dave is on the right track to look for a tolerance that we could regard as "normal practice".  Customers can always opt to pay for better if they want.  I'd have thought within a few cents would be "good enough".  

 

Now this is not a question we have to leave up to the theorists.  We can all look for intervals on our instruments that we think are a little testy and measure the two notes and report back.  But don't expect anything other than unisons, fifths and octaves to sound smooth.  Even fifths are out by 2 cents, and thirds 14 cents from their natural relationships.

 

Perhaps a "perfect fifth" being 2 cents out but not normally making us knash our teeth confirms that a workaday tolerance of a few cents is pretty good?  For that matter, how many of us run screaming from the room if someone accidentally plays a third?

 

Terry



#7 Rod

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Posted 15 March 2014 - 03:06 AM

Terry, your Cornish tin-worker had the best answer. He was obviously living in the real world.

#8 JimLucas

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Posted 15 March 2014 - 03:14 AM

FWIW (not much).  A dime is 10 cents, and a nickel is 5.

 

So that's your "ten cents worth"... ;)

 

When I was young, the usual expression was "two cents worth"... but with inflation, who knows what that comes to in today's cents?  :unsure:



#9 Johann

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Posted 15 March 2014 - 03:48 AM

Terry, your Cornish tin-worker had the best answer. He was obviously living in the real world.

i also would put it this way, if a customer says a note is not as he wants this note then fix it, don't do more as asked, because changing to much my affect more as one my think. It is never a question how accurate a instrument is tuned to a special theoretical scale. 

I average it is normal to tolerate two cents of errors to the expected pitch, but i don't  say this is my standard. I also try to get it as good as possible but zero error is not possible.  0,5 cents tolerance is not possible if looked on it over time and after some time there is again some variation. I also noticed that instruments may even be more appealing to some costumers if there are some or variation in pitch. On diatonic instruments some notes in a scale may be even more of the equal tempered sale as others. Difficult are: tones that accrue more as one time on the instrument this tone must be more accurate and at the same pitch, 5ths and octaves are the second important to look at. Low notes have to be in tendency to high because of the pitch drift if air pressure is high wile played with more volume.

Notes in the upper range may also be tuned a bit sharp because of the human ear. In the higher range errors arr not as easily noticeable as in the middle range, and we tend to hear in this renege rather stretched, so it is better to use the ear in the final check. All in all one cant tell a standard for all notes, it depends on many factors way one note may tolerate an error even up to 10 cents and a different note on the same instrument must be as accurate in compaction to the other to 0,5 cents. Please keep also in mind that i don't talk about concertinas i only tune chromatic and diatonic instruments. Instruments with one reed on each tone or instruments with registers are also a bit different as Instruments with two or more reeds for each note.

 

As to the reference of the instruments, in most cases musicians here want the pitch set to 442Hz. i have now two instruments final tuned one to a reference of 442 the other to 443 and if both are planed by two musicians at the same time the advance cant tell the that there is a difference in pitch. 


Edited by Johann, 15 March 2014 - 03:55 AM.


#10 Terry McGee

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Posted 15 March 2014 - 04:02 AM

When I was young, the usual expression was "two cents worth"... but with inflation, who knows what that comes to in today's cents?   :unsure:

 

We might be able to extrapolate from the current cost of a pennywhistle?

 

Terry



#11 d.elliott

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Posted 15 March 2014 - 07:02 AM

Dave,

 

With all due respect, some of the things you said scare me.  I fortunately or unfortunately am very sensitive to tuning issues.  This statement really bothers me:

 

"This 5 cents detection was hearing two continuous notes, I reasoned that musical notes are transitory, a MM of 60 beats would give each note 1 second if playing crotchets, 1/2 a second if playing quavers, clearly MM 120  halves all this again, So +/- 2.5 cents seamed reasonable, say +/- 2 cents to allow for drift etc."

 

Reminds me of an old music joke: If you play fast the mistakes don't last as long.

 

I would think that you would want to do the best job you are capable of on each instrument regardless of whether or not the customer can hear the difference, i'm sure you can tell the difference!  What about the other musicians that listen to this instrument and might or might not want to know who tuned it!

 

I've tried my hand at tuning, and know it can be difficult, time consuming, and a PITA, but that is why I would send an instument to a proffesonal, not just a "repairer"

 

Not to sure I would be happy with your "tolerances"

 

I think it would be good to determine an agreed standard, to protect players. How about +/- 0

 

Sorry but your post moved me to respond,  I mean no disrespect.

 

Doug

 

 

Doug,

 

Actually your response is provocative, if not offensive,

 

 +/- 0 is impossible, and there are many variables, where +/- 1.5 cents appears an unattainable target. Practically there has to be a time where you finish converting a reed into baking foil. If a tolerance is +/- 1.5 cents, then the majority of reeds will lie between +/- 0.5 cents (66%), and 98% will  lie between +/- 1.0 cents, (Normal distribution). 

 

If you are implying that I cut corners, by not trying my best on each instrument then that is offensive. 

 

What I am trying to do is to establish some informal ground rules that players can expect form repairers, not just rough tuned instruments as commented by Stephen. .

 

I certainly take Johann's point that there are many variables in play, and I also do advise players, where practicable to take the concertina away, play it four a couple of weeks, then bring it back for tweaks and adjustments, I say this not because I expect problems, and not because I am using the player for my own Quality Control, but because things can settle, drift, move and everyone's ear is different and players play in different musical landscapes and have there own favorite chords and their own styles and playing pressures. Obviously testing octaves 3rds and 5ths is by ear as much as by instrumentation

 

Terry is right, I do not use an analogue tuner, for fear of parallax error. He is also right about time, costs and what people are prepared to pay for. Although I am more interested in a consensus about what people should be offered, and hence expected to accept. 

 

Stephen targets 0 to +1 cent, plus ear over tune; and I thank him for being brave enough to declare his working standards. I would like to hear what others are doing, including some manufacturers. As Stephen comments, reeds an be unstable and I know that getting a reference value can be 'problematical' but we all have an approach and what we consider acceptable.

 

 

 

Dave



#12 Terry McGee

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Posted 15 March 2014 - 07:15 AM

I wonder if there is any argument to be made that Duet and English concertinas should be subject to a tighter tuning specification than Anglos?  Could it be argued that the Anglo is primarily a melody instrument with occasional sparse chords thrown in, and so there is not so much scope for detecting mild tuning anomalies.  While perhaps at the other extreme, the Duet is an instrument designed to accompany itself or argue with itself, allowing much more chance to be offended by testy intervals.  With the English nervously occupying the centre ground?

 

If we did swallow that argument, how would we weight the specifications?  Should the Duet be twice as tight as the Anglo?  And the English √2?

 

Terry



#13 Stephen Chambers

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Posted 15 March 2014 - 07:32 AM

+/- 0 is impossible, and there are many variables, where +/- 1.5 cents appears an unattainable target. Practically there has to be a time where you finish converting a reed into baking foil.

 

I totally agree, and only someone who has never tuned a concertina would suggest otherwise.



#14 d.elliott

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Posted 15 March 2014 - 08:15 AM

I wonder if there is any argument to be made that Duet and English concertinas should be subject to a tighter tuning specification than Anglos?  Could it be argued that the Anglo is primarily a melody instrument with occasional sparse chords thrown in, and so there is not so much scope for detecting mild tuning anomalies.  While perhaps at the other extreme, the Duet is an instrument designed to accompany itself or argue with itself, allowing much more chance to be offended by testy intervals.  With the English nervously occupying the centre ground?

 

If we did swallow that argument, how would we weight the specifications?  Should the Duet be twice as tight as the Anglo?  And the English √2?

 

Terry

 

Terry,

 

When Tuning English and duet concertinas there are two additional dimensions to the set up of the reeds, whilst evident on Anglos these two features become more critical on instruments that play the same note in both directions of bellows operation.

 

1. Balancing the note pitch, you have to be able to change direction of bellows without any discernible difference in note pitch, including chords.

2. Equalising responsiveness: you have to be able to  to sound a note in either direction of bellows travel, at precisely the same apparent bellows pressure, usually one as close to playing pppp as possible, even on a metal ended instrument.

 

I refer to 'apparent bellows pressure' because the physics of air movement and way bellows are constructed/ stored/ 'matured' all have a part to play in this

 

When you have got that as right as practicable, then normal tuning tolerances will still apply, but in final tuning the above two characteristics for each key must always be maintained. The goal of responsiveness also brings in elements such as  valve condition, and matching as well as reed set etc.

 

Dave 



#15 Johann

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Posted 15 March 2014 - 09:16 AM

When Tuning English and duet concertinas there are two additional dimensions to the set up of the reeds, whilst evident on Anglos these two features become more critical on instruments that play the same note in both directions of bellows operation.

 

It is not that easy, if a diatonic box has more as one row you find some notes doubled on different rows as alpine type boxes do have a few notes as Gleichtones and extra accidentals as well. I tune in most cases chromatic b-griff or diatonic boxes and in most cases it is easier to tune a chromatic box as a diatonic box. And don't forget it is not us that make's the standard it is the musician who demands special criteria. Most professional musicals do have very individual likes or dislikes. 

More important as the actual pitch is often that the reeds do respond at a equal level of pressure and the way the player wants the reed in respect of punch and power. One cant have all, reeds that can be sounded at very low pressure are in most cases not wanted because many musicians also want to play with more power. I personalty like the reeds to be very easy to sound and no or very little tremolo for use indoors, but that's me. For instruments with wet musette tremolo the tolerance in pitch is much more anyway. If the instrument is one of the expensive types with best quality reeds and register switches it is again more critical and also achievable to tone to more accuracy, but also in this case it is the musician who demands the the amount accuracy and the person who tuns must be able to explain to musician all aspects the musician wants to discuss. The musician mast be comfortable with the result not by looking of the readout of a electronic tuner. People should not be encouraged to check instrument with electronic tools, Better ask the the reader of the book, you are writing, is his ear trained enough to hear the differences? Or ask is he happy with the sound of this box at all by just subjectively checking when someone else is playing the box. Using electronic tuners is of some help for a tuner the final check always is made by ear. So it a customer is not trained enough, cheeking instruments with electronic tuners leads in the wrong direction. Or put it the other way if it would be possible to tune a box exactly to 0 cent offset with the equal temperament scale than the outcome would be disappointing, and the instrument would sound misstuned and liveliness.  



#16 Greg Jowaisas

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Posted 15 March 2014 - 09:27 AM

I use a Peterson Auto Strobe.  In general it takes me 5-6 passes to tune an instrument.   The last two passes get everything from 1 or 2 cents down to zero.

 

Differences in pressure can cause a note to vary several cents.  I usually try and get an idea how each customer plays (loud, soft, aggressive, laid back) and use that kind of pressure to tune a concertina.

 

Then the fun begins.  The pressure differential of individual notes when forming chords begins to rear its ugly head.  So double checking on whether the notes are in tune with each other when played as a chord merits another pass or two.

 

The imperfect 3rds in equal temper tuning can be especially annoying on a concertina.  I find it is very important to my ear that they are not the least bit sharp on the meter.

 

Occasionally I tune a concertina to 1/4 comma mean tone.  The perfect thirds are music to my ears and the compromised 5ths at least tolerable.

 

I also find it is not a bad idea to wait a day or two between the 3rd and 4th and 5th and 6th tunings.  Reeds seem to "heal themselves" between tunings and can go a half to a couple of cents sharp.  (Perhaps someone can explain if there is a metallurgical reason?)

 

Greg



#17 Rod

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Posted 15 March 2014 - 12:45 PM

My experience is restricted solely to the Anglo. Would I be correct in assuming that a reed consists of two distinct characteristics.....pitch and tone ? For an English Concertina, with it's pairs of reeds, it must require enormous skill to ensure that not only is the pitch of each pair precisely the same but the tone also. It sounds as though pitch can be 'measured' electronically with extreme accuracy but does the same, or something similar, apply to the the equally important measurement or analysis of tone ?

#18 Stephen Chambers

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Posted 15 March 2014 - 12:53 PM

Gosh Greg, I think your customers must be a lot more patient than mine, who usually want their instrument back the same day (or even within a couple of hours!) because they've got gigs to play, and/or they're teaching, have to be back at Limerick University on Monday and need the concertina for their course, or they're going in for a competition in a couple of days time - though he did win it! :rolleyes:

 

Mind you, I'd say all those extra "passes" are a helluva-lot easier and less time-consuming on your Peterson Auto Strobe than my trusty old Yamaha PT-4, even if it was "state-of-the-art" (and £1,000! :blink: ) back in the mid-'70s. I've sometimes done mean-tone on the Yamaha too - but the mental arithmatic it requires is painful.

 

I have thought about getting a Peterson though...

 

Is it the 490 you've got?







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