It is currently Sat May 18, 2024 10:54 am


wind model values

Using the CODM to create your own organ definitions, exchange CODM organ definitions, ...
  • Author
  • Message
Offline

marclabru

Member

  • Posts: 19
  • Joined: Fri Mar 03, 2023 3:11 am

wind model values

PostSat Apr 29, 2023 5:00 am

I'm working on a romantic composite codm organ.
I'm experimenting with the windmodel and trying to find good values for totalreserv and dampingcooeff.
I have used som similar to the St annes as a staring point:
total reserv 2.5 and damping coeff 25.
my codm is a bigger orgnthan the st annes with lots of 8 and 16 ft. my question is what is a reasanable value for totalreserv for a big romantic organ? (2.5 m3 seems to me already wuite big for a reservoi, but bigger organs may have more than one reservoir for each division?).
Offline

larason2

Member

  • Posts: 769
  • Joined: Thu Feb 04, 2016 9:32 pm

Re: wind model values

PostSat Apr 29, 2023 11:23 pm

In the CODM, the reservoir size is handled by division. So, each division needs its own reservoir size, handled by the following tag:

<WindModel_TotalResrvrAndWndchstVolMetresCub>

As I mention in my "How to CODM" document, my recommended starting size is 1 metre cubed for most divisions. For a pedal division with a lot of wind consumptive stops, I might do a bit more. If the ranks in the division are well winded, but sound static, this number is too high. If they sound a bit flat and are constantly wavering, this number is too low. For the damping coefficient, the recommended number by the CODM manual is 5-10, with my recommended being 7. As far as I recall, high numbers increase the wavering over what they would otherwise be, and low numbers decrease it. In my opinion, the St. Anne's model reservoir you mentioned is a bit too big with a damping coefficient that is a bit too high. However, this would create a robust wind supply with still a fairly artistic starting transient, which may be more applicable for a starting programmer. I like more dynamic transients and relatively more limited wind supply though, hence my recommendations, however my recommendations would need more fine tuning of the ranks to get them to sound good (though I think this makes them sound more interesting).

For me a big Romantic organ would have say 50-75 stops? Say 3 manuals and a pedal, about 17 stops each. I'd only go up to 1.5 metres cubed if there are a lot of 16 foot stops, say more than 1 or 2. Even with eight 8 foot stops, you usually only register at most 3 or 4 at a time (otherwise it can get muddy). The higher pitched stops typically don't consume that much wind. If you have lots of 16 foot stops, or say one or more 32 foot stops, then I might go up to 2 metres cubed, but I usually make do with 1.5 for my pedal divisions. As I say in my guide though, usually the wind supply is the last thing you manipulate in the organ, once it is practically done. You have to hear what the opening transient sounds like on all the ranks on all the divisions, and then adjust the division table values first to get the ranks in the ballpark, then the individual rank values after that as part of their voicing. Others may have more advice though.

Here's the link to my guide:

https://www.exercisesincatholicmytholog ... ank-page-1
Offline

marclabru

Member

  • Posts: 19
  • Joined: Fri Mar 03, 2023 3:11 am

Re: wind model values

PostSun Apr 30, 2023 9:01 am

Thanks Larason2 for your answer.
Your guide is great by the way! I use it all the time! Thank you so much for making that!
As you say the values in the CODM example of St Annes seem quite high. Today I played on a big romantic organ, went inside and measured the reservoir, together with the windchest I guess it would be about 1,4 m3.
On my CODM I am using the Demo of Chemnitz for my 1. manual. And even with the same numbers as in the St Annes it's still not as stable as the original. Therefore my question. I use 3 perspectives per stop by the way(distant, diffuse and rear), that consumes more wind I suppose?
Offline
User avatar

mdyde

Moderator

  • Posts: 15499
  • Joined: Fri Mar 14, 2003 1:19 pm
  • Location: UK

Re: wind model values

PostSun Apr 30, 2023 9:16 am

Hello marclabru,

marclabru wrote:Therefore my question. I use 3 perspectives per stop by the way(distant, diffuse and rear), that consumes more wind I suppose?


Yes -- since the perspectives are implemented as additional virtual 'ranks', three perspectives would draw three times as much wind.
Best regards, Martin.
Hauptwerk software designer/developer, Milan Digital Audio.

Return to Custom Organ Design Module (CODM)

Who is online

Users browsing this forum: No registered users and 1 guest