Swellboxes and crescendo wheel
Swellboxes are enclosures with vertical venetian blind-type shutters controlled by the swell pedals (or ‘swell shoes’). As a given shutter closes, the pipes contained in that swellbox will sound quieter and darker (with lesser amounts of high overtones). The Scots Organ’s swellbox characteristics are brought to life through modeling.
The Scots pipe organ contains 3 MIDI assignable swellbox pedals and all divisions are virtually enclosed. This means that once you assign a swellbox pedal to an enclosed division you can control its state instantly.
Each enclosed division has its own independent enclosure charasteristics. Once you change the swellbox pedal to division assignment, you can control the enclosures of different divisions one-by-one, but multiple assignments (one pedal controls more) are also available. The indicators on the Stoplist Page show the swell pedal states.
To assign the three swell pedals to various enclosures, you can use the assignment buttons on the Keyboards Page.
Labeled with Sw1, Sw2, and Sw3 - which does not have a pedal on the GUI, but assigned to a pedal via the Expression/Crescendo Pedal menu of Hauptwerk - each swell pedal can be assigned to control one or more divisions. For example, if you would like to control the Swell and the Positive together with a single pedal, just assign both of them to Sw1. The state of the swell pedals is set to default once you assign them to an other division.
The crescendo wheel is an axially rotating drum operated by foot control, and is used in place of a conventional crescendo pedal. The wheel is positioned to the left of the foot-operated swellbox pedals. Sliding (rolling) it forward from position 0 to a higher position triggers stops in a preset user-defined manner, according to the sequence contained in the respective Crescendo Program. There are 4 independent crescendo programs available, labeled A, B, C, D. Two of them are pre-loaded in the instrument, but you can freely modify them.
The figure below shows the Console Page, highlighting the crescendo pedal (left pedal), two swell pedals (middle and right pedals), and the display showing the state of the crescendo pedal.