Tunelab 97 tuning curve

Ron Koval drwoodwind@hotmail.com
Fri, 16 Jan 2004 15:00:48 +0000


Hi Charles,

Looks like Bob found out what was going on.  I had my copy set to "beats", 
so that's why I saw it flat.

As for a way to manipulate tl97, I'll have to go the "Star Wars" route, and 
tell you to "trust the Force, Luke".  No, really...  This might get a little 
long, but here goes:

We make a few key assumptions when using this type of tuning gear:

1. The piano maker has produced a scale that is fairly consistant in 
inharmonicity changes from end to end of the scale.

2.  If we set the machine to listen to one partial, and then make a smooth 
curve with that partial, the other partials will follow a predictable 
pattern to make the "whole sound" work.

In some pianos, these assumptions are pretty close, but in many pianos, 
especially the "challenging" pianos, these assumptions are far from true.  
So what's a tuner to do?  Combine the best talents from the technician, and 
the machine.  We are best at judgements, or comparing.  That is, what note 
sounds better?  A machine could tell you all sorts of things about the 
notes, but it has a harder time telling which one sounds better.  Machines, 
on the other hand, are great at manipulating numbers.   So splitting the 
octave into 12 little pieces is no sweat.  In fact you may hear someone 
claiming how good a machine can set the temperament; well, duh, that's what 
they do best.  But when you ask a machine to tell how wide to set the 
octaves.... that's where it struggles.  It could easily set it to a 6:3, 
4:2, or a 2:1, or any amount above or below, but you just want it where it 
sounds best.  News flash: That "sweet spot" will be different depending on 
the instrument in front of you.

So try this:

Open the "average piano" file in tl97.  This gives you a starting point.  
You will be tuning and notating the placement of all of the A's.  I'm asking 
you to "trust your ears, Luke".  Think like a symphony player, ignore 
specific octave types, or partials at this point.  You are looking for the 
smoothest placement of the octave, without using any other checks.  Set A4 
to the machine, just work with one string, so bring a bunch of mutes.  Tune 
A3 to the machine.  Play them together.  Shift A3 a little sharp, a little 
flat, find the best spot.  Did you end up where you started?  The machine 
makes a great "bookmark".  If not, find the offset and either add or 
subtract to find the new stretch, or use ctrl E to transfer the offset to 
the stretch. (changing the tuning curve)

See where I'm going?  This really goes fast, about the same time it would 
take to sample all the notes you need to have the machine calculate a 
tuning.  Next tune A5 to the machine.  Repeat the offset and stretch, but 
this time make sure you check A3 against A5.  Find the "best" location.  
Continue out to the ends, checking the doubles, triples and more as you 
extend out to the ends.  You will now either have written down where the A's 
belong, or have a curve with the A's out of place, allowing you to copy down 
the numbers for the A's

You need to write down the numbers and then reload the file (without 
saving!) to get back to the smooth curve.  Now use the linear dragging 
function to move the curve while anchoring from what your ears have found to 
be "best".  So, anchor A4, and put the curser on A5 so you can watch the 
numbers move to the selected spot.  Next, right click on A5 to move the 
arrow, then drag A6 to where it wants to be.  Finish the top with A7.  It 
will probably be much higher that where it started.
Going down through the break and into the bass is where things usually get 
interesting.  If you really wanted the tuning curve to match the piano more 
closely, you might have to tune and set intemediate notes at the stringing 
break to push and pull the curve around.  So you end up with a curve that 
doesn't look like anything you've seen before.  Hmmmm... what's going on?  
It's because the automated curves tend to use the assumptions from above, 
which may not apply to the piano in front of you.  Once again, trust your 
ears to do what they do best:  compare and find the "best" spot for the 
octave(s).

This method can also work with any machine that has a customizing function 
to let the user have some control over the octave widths.  Also, if you only 
have a few options to choose from, you can simply cycle through the options 
untill you find one that most closely matches the placement of the A's 
pre-set by your ears.

Happy tuning!

Ron Koval
Chicagoland

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