Pipe Wind Pressure

[Guest]

I saw a device for sale that supplied two different pressure to a rank in order to give is a loud and soft feature, and didn't realize that it was possible for a pipe to play at varying wind pressures. Which brought me to this question: How much can the wind pressure given to a single pipe vary by? Say a pipe is voiced for 4" wind pressure. Could it play at 3.5"?

[Havoc]

I'd say it would play but likely a bit out of tune.

[Westminster]

Yes, but such devices inevitably result in out of tuneness of the pipes affected. I've never seen them used except for pedal Bourdons. They can be quite effective for the bottom octave or so, but the tuning problems increase at higher pitches.

[Guest]

But what if the rank was voiced for 4", and I set it up on a chest that was 3.5", would it play? I know it will need retuning, but does it need revoicing?

[Westminster]

It would depend on the style and details of the voicing. There's no single comprehensive answer to your question. There might be little difference except a bit softer. If the style of voicing is such as to yield more of a difference then it may be necessary to trim pipes to get them to tune. It has to do with the effective efficiency in terms of wind utilization of the voicing style.