Reed Pipe Scaling

[JWAnderson]

Hi everyone.

 

Over the last couple of days I have been trying to design a small two manual organ in more detail than usual working out pipe scales etc. I've managed to work out the flue stops, but my question is what sort of scale do organ builders use when trying to scale reeds?

 

I've had a search around the internet and various organ supply catalogues (Laukhuff etc.) but they only seem to have flue scales or the measurments of all the C pipes.

 

Cheers

 

Josh

 

P.s. Another thing I was going to mention was that I had seen some examples of reed pipes where the diameter at the top of the resonator stays the same right up to the top note, but also some where it progressively gets smaller. What would be the advantages of either of these methods?

[Pierre Lauwers]

The question of reed pipes scaling is a complex one, as there obtains

more freedom there than with flue pipes.

The bodies are there only for the tone, the relation note/lenght is

only secondary (you can build half-lenght, quarter-lenght or even

shorter bodies, for Regals like Vox humana etc). The same is true with

the diameters.

There are several referencies, for example Dom Bédos. This book is

one of the most important we have, written by a professionnal involved

with practical matters.

So he gives us data and facts.

But those are only an example, what was done in the second half of the 18th

century in southern France. This is NOT the organ for Couperin and de Grigny,

whose reeds were actually different. The Dom Bédos scales had at least as much

influence on the late baroque german organ as on the french one, and even

on Eberhard Friedrich Walcker.

 

A later reference was Töpfer, who gave a simpler way, with linear scalings.

He had not much influence on the german romantic organ, but more later,

during the 20th century, because his formulaes were practical for industrial

pipe-building (standardization).

 

The first edition of his main book is on-line for free here:

 

http://books.google.be/books?id=HCUWAAAAYA...;q=&f=false

 

After having downloaded the file, go to page 143 (169 for Adobe Acrobat).

 

If the link does not work, go to Google books and enter as search words:

 

"Die Orgel: Zweck und Beschaffenheit ihrer Theile, Gesetze ihrer Construction ...

Johann Gottlob Töpfer"

[JWAnderson]

The question of reed pipes scaling is a complex one, as there obtains

more freedom there than with flue pipes.

The bodies are there only for the tone, the relation note/lenght is

only secondary (you can build half-lenght, quarter-lenght or even

shorter bodies, for Regals like Vox humana etc). The same is true with

the diameters.

There are several referencies, for example Dom Bédos. This book is

one of the most important we have, written by a professionnal involved

with practical matters.

So he gives us data and facts.

But those are only an example, what was done in the second half of the 18th

century in southern France. This is NOT the organ for Couperin and de Grigny,

whose reeds were actually different. The Dom Bédos scales had at least as much

influence on the late baroque german organ as on the french one, and even

on Eberhard Friedrich Walcker.

 

A later reference was Töpfer, who gave a simpler way, with linear scalings.

He had not much influence on the german romantic organ, but more later,

during the 20th century, because his formulaes were practical for industrial

pipe-building (standardization).

 

The first edition of his main book is on-line for free here:

 

http://books.google.be/books?id=HCUWAAAAYA...;q=&f=false

 

After having downloaded the file, go to page 143 (169 for Adobe Acrobat).

 

If the link does not work, go to Google books and enter as search words:

 

"Die Orgel: Zweck und Beschaffenheit ihrer Theile, Gesetze ihrer Construction ...

Johann Gottlob Töpfer"

 

Thank you Pierre, this has made it clearer for me.

 

With regards to the diameter at the top of the pipe, would it be correct to say that if the scale was larger it would provide a darker tone and vice versa?

 

Joshua

[Pierre Lauwers]

Thank you Pierre, this has made it clearer for me.

 

With regards to the diameter at the top of the pipe, would it be correct to say that if the scale was larger it would provide a darker tone and vice versa?

 

Joshua

 

There are too much variables at play to allow for "this equals that" shortcuts.

Let us take the Arthur Harrison Tromba for example, as it is one of the preffered

chorus reed stop on this board ( ).

The darkness of its tone is due to a combination of heavy wind, tick tongues, nearly

closed shallots, and "harmonic" bodies, i.e., double lenght.

But the actual scales of those stops are narrower than those of many french

and belgian organs of the same period (or earlier, say 1870-1900), whose tone is

considerably "freer".

 

Pierre

[ajsphead]

and a different curve.

 

AJS

[CTT]

Are you planning what type and style of reed stop you want in the organ? Or have you decided that and are wanting the scale of each note so you can plan the layout of the soundboard?

CTT

[JWAnderson]

Are you planning what type and style of reed stop you want in the organ? Or have you decided that and are wanting the scale of each note so you can plan the layout of the soundboard?

CTT

 

I have decided there will be four reeds on the organ; Bassoon 16p on Pedal, Clarionet 8p on Great, Trumpet 8p and Hautboy 8p on Swell.

So yes I would like the scales to plan the layout.

 

JA

[CTT]

I have decided there will be four reeds on the organ; Bassoon 16p on Pedal, Clarionet 8p on Great, Trumpet 8p and Hautboy 8p on Swell.

So yes I would like the scales to plan the layout.

 

JA

As you were saying you had the measurements of the C's, it's a simple matter of then getting hold of a set of pipe scaling disks and finding the right progression in the series to match the measurements from the C's that you have with the 11 intermediate disks until your next definite measurement being the C an octave higher. That way you can lay out your soundboard on a one to one scale, which helps in planning slides, bearers, screws, access for little things like hands, fingers reed knives etc... and to also plan the positions of you stays.

 

CTT