Diapason Strength

[Guest]

A post referred to the fact that a single unified Diapason is not "correct" since the higher pitches need to be voiced louder. It would seem that equal volume over the keyboard range would be the most desireable. Thus 8', 4', 2' pitches would be roughly equal in volume. The comment stated that the higher pitch ranks should be louder or scaled differently.

If anyone can shed light on this question, please post an answer as this issue is not clear to me. Thanks in advance for any answers.

[odellorgans]

Re: Diapason Strength

Generally speaking, one looks for a certain amount of mild ascendancy in the volume of the pipes as one goes upwards in the compass. The effect is subtle, and to the "lay" listener shouldl actually seem transparent. These and other elements are the crux of a good tonal finishing.

This is not a had and fast rule, however. The use of ascendancy (or the absence of it) will vary according to acoustical and muscial requirements.

When a chorus (8-4-2, for example) is present, often successive voices in the chorus are voiced at lesser power, so as not to create an overwhelming effect. Practices vary by builder and voicer. Without proper scaling relationships and voicing technique, the stops of the chorus will not blend, but fight each other for dominance.

Using unification of a single rank as oppposed to the use of a properly scaled and voiced chorus creates a result that lacks depth; in counterpoint, inner voices often are lost.

I should point out that the use of unification is not "incorrect" but more a musical compromise. Unification can be done carefully and creatively to achieve very rewarding results when space and/or financial constraints exist.

[Guest]

Re: Diapason Strength

Thank you for the explanation.

[odellorgans]

Re: Diapason Strength

You are more than welcome!

[Bombarde32]

Re: Diapason Strength



I would like to second Mr. Odell's opinions. But I speak from personal experience rather than knowledge of building or tonal finishing. Our church has an unenclosed 8' Principal out as the facade and an extended rank in the front of the box that the 4' and 2' Principals are drawn from. Obviously the 4 and 2 foot are quieter ... and it is very very annoying.

It sounds much better to hit the 4' coupler and take the 4' Principal from the 8' rank and then only turn on the 4' Principal rank (which since it is coupled also gives the 2'). So you end up with 8', 4' from the 8, 4' from the 4' rank and 2' from the 4' rank (8/4/4/2). It is a MUCH more pleasing sound. It sounds more balanced even though you have two 4' selections playing. Unless I need the swell for something else I'll usually couple down the 2' Flautina to beef up the 2' pitch as well.

[Havoc]

Re: Diapason Strength

Normally this is done to give more upper frequency volume. One of the reasons is that high frequencies don't travel as well as the lower range. So in larger spaces like churches, an organ with a uniform scale or voiced for equal strenght would sound lacking in the highs.

This is one of the reasons that using a church organ in a house much smaller than it was build for often sounds screeching.

There have been other techniques used, like doubling the pipes in the higher octaves.

[odellorgans]

Re: Diapason Strength

[quote user="Havoc"]Normally this is done to give more upper frequency volume. One of the reasons is that high frequencies don't travel as well as the lower range. So in larger spaces like churches, an organ with a uniform scale or voiced for equal strenght would sound lacking in the highs.

This is one of the reasons that using a church organ in a house much smaller than it was build for often sounds screeching.

There have been other techniques used, like doubling the pipes in the higher octaves.[/quote]

While it is an ingenious solution, I would point out the doubling of flues for power in the treble range is something that is done pretty rarely, and most commonly found on the upper ends of high pressure reeds.

Manual reed stops often tranition to flues somewhere in the top octave. The exact note where this takes place varies by builder and tonal designs/requirements. Break points at 49, 54 and 56 are the most common.

On occasion you can encounter stops that have 61 reeds, but in that upper range they can be notoriously unstable.

[KleinErzahler]

Re: Diapason Strength

Greetings,

Incidentally, I should insert a small comment to go along with the unification thread I started elsewhere....

One technique that has been used with success as far as unifying Diapasons go is to take advantage of the similar subservient relationship that the 16', 4', and even second 8' ranks have with the primary Diapason in a "proper" chorus.

Within this context a unified Diapason can find itself acting very much like that which would be found in a similar straight instrument. You can find this arrangement in all sorts of early 20th century American instruments, such as Mollers and Kimballs. But in any case you will usually find that the First Open is 61 notes and not unified, with the Second Open serving other purposes.

Our resident organ builder here on the forum has been known to take advantage of such opportunities as well.

(C:

- N

[KleinErzahler]

Re: Diapason Strength

Just to sort of take this thread somewhere else....

The one thing that irks me, even though I love organs with 8' tone, is when something like the Great Diapason obliterates the rest of the organ in power. There are also some organs around that have a similar reed such as a Trumpet - everything in the organ could be wonderful, but then when these stops are pulled on the party is over.

I have always been a big fan of incremental steps in power between 8' flues and there are several fine examples around, such as a 1910's Steere where the Aeoline, Dulciana, Salicional, and Swell Diapason are all close together to the point that even the softest adds color to the rest.

- N

[Guest]

Re: Diapason Strength



Church organs built in the teens and 20s along American Symphonic lines ; small, medium and even large organs --followed a certain formula that was established as a common practice--namely---while most stops were graduated in dynamic power for an incremental build up from very soft or softest=dulciana, aeoline, viol d'amour, viol aetheria, flauto dolce, etc to loud= diapasons, large-scale open and covered flutes and tuba , tomba or trumpet reed stops---the Great Open Diapason 8 was sometimes left outside an enclosed great or great/choir box---for the purpose of filling a given space with a flood , avalanche, mud slide of thick, opaque, diapason tone---often with leathered lips---so that it alone topped off full organ aided by the enclosed tuba 8 on high wind pressure.

Sometimes a small organ of say 10 stops had an enclosed Great Open Diapason 8 with toe holes wide open for congregational accompaniement and the other9 much softer stops for choral or solo organ use. On larger organs when there were two Great Open Diapasons 8 one was smaller in scale and power, more along the lines of the rest of the Great pipework, and the big one of 40, 39, 38 or 37 scale of common metal with a 2/9 or 1/5 mouth was the big gun as described above...

So the obliterating was purposeful--to fill a space that really needed a chorus ---well-developed with 8-4-2-and mixture--instead; the huge diapason and often huge dark tromba, tuba or chocolatey trumpet for economy and a tight budget. Builders could not afford to easily turn away work because it wasn't what they preferred in terms of design. Organists were not very demanding as to upperwork so the trend became as mentioned herein--many soft and moderate voices if possible--and a few loud big overpowering ones to fill a room with organ tone!

G. Donald Harrision found these big fat Opens perfect for adding an internal bung or capping to make the new organ Great 16 Quintaton.