Rank Two is a synthesiser designed specifically to simulate the sound of a rank of pipe organs.
A rank is a single set of pipes tuned with a similar sound and assigned to a chromatic scale covering typically 5 octaves. Usually more than 1 rank makes up a “Division” and a Division will be assigned to one keyboard manual, with the possibility on a real organ of coupling Manuals/Divisions together so the performer can play several ranks and divisions simultaneously.
Rank Two plugin is intended to have several instances in the DAW to give a “mixture” to create a fuller sound. However, a single plugin instance is capable of a wide range of full sounds as demonstrated by some of the presets provided. Use of the extensions is an easy way to build a big sound with fewer instances running in the DAW.
Physical Modelling is used for the wind/pipe interactions and sinewave-based additive synthesis for the tone itself. These two sound generators interact in terms of amplitude, and the sound thus created was tuned at the design stage to give results close to real pipe sample sets I have auditioned. The Reed section uses one of 15 reed waveforms, created in my Quilcom Wavemaker 4, to excite a bank of harmonically tuned resonant filters with very high Q, to give a more defined and controllable spectrum.