Swellbox and crescendo wheel
Swellbox is an enclosure with vertical venetian blind-type shutters controlled by the swell pedal (or ‘swell shoe’). As a given shutter closes, the pipes contained in that swellbox will sound quieter and darker (with lesser amounts of high overtones). The Heppenheim Organ’s swellbox characteristics are brought to life through modeling.
The Heppenheim pipe organ contains a MIDI assignable swellbox pedal and all divisions are virtually enclosed. This means that once you assign the swellbox pedal to an enclosed division you can control its state instantly. To assign the swell pedal to various enclosures, you can use the assignment buttons on the Keyboards Page.
For example, if you would like to control the Schwellwerk and the Rückpositiv together with the pedal, just assign both of them to the swell pedal by pressing “Sw”. The state of the swell pedal 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 pedal. 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 I, II, III and IV. One of them is pre-loaded in the instrument, but you can freely modify them.
The figure below shows the Console Page, highlighting the crescendo pedal (left pedal), the swell pedal (right pedal), and the displays showing the state of the two pedals.