There are three criteria for judging a digital church rgan: Musicality, Reliability and Value.
Virtual Organs include compromises in Musicality, Reliability and Value, as compared to a real digital church organ.
Most digital organs, whether based on PC’s or dedicated tone-generation technology, use sampling in which pipe sounds are recorded and stored in the organ’s memory for playback. The most accurate tonal results require that pure pipe sounds be recorded with the microphone placed close to the pipe so that extraneous noises and the acoustics of the building do not corrupt the recorded sound. This “dry” sampling technique is more complicated than placing the microphones farther out in the room.
PC-based organs, referred to as “Virtual Organs”, most often place the microphone out in the church when pipes are recorded. This process is referred to as “wet” sampling since the acoustics (reverberation) of the building, are also recorded. In addition, extraneous noises including undesirable clicks and clacks from the pipe organ are recorded. When wet samples are played in a room with its own acoustics, the recorded and real acoustics “collide” producing unnatural results. Also, the recorded extraneous noises become distortions in the sampled sound. Playing a Virtual Organs is more akin to playing a recording of an organ, rather than a real-time musical instrument.
Reliability & Longevity Differences
Pipe organs typically last for decades. A digital church organ can only meet this goal by being designed and built with quality. Just as important, the builder must use components that can be supported long in the future and the builder must have the financial stability and capability enabling long-term support. Virtual Organs are lacking in these areas, typically being produced by small companies with little capital.
PC-based organs are basically kits, comprised of PCs from one supplier, sound software from another (often Hauptwerk), MIDI controllers, organ consoles, keyboards, stop controls, etc., from other various suppliers. No company is responsible for the entire product and the third-party suppliers are typically small and poorly capitalized. Support and warranty for the organ will only be as good as that of the weakest sub-assembly supplier, a risky venture for purchasers.
Finally, the lifespan of a PC is about five years. This coupled with the reality that Windows and Apple operating systems are constantly changing makes longevity for PC-based organs problematic.
Value is a function of quality and price. High quality at an affordable price equals true value. The chief benefit of Virtual Organs falls to suppliers who can avoid R&D investment and long-term product support responsibilities. Incredibly, when Virtual Organs are provided with quality subassemblies, they often cost as much, as a real digital organ.