ELECTRONIC ORGANS  VERSUS PIPE ORGANS


Here is summarized all objective arguments I know related to digital organs. They are the proof that never a digital organ will be able to surpass
a real pipe organ, even with the help of new technological improvements.

But clearly one can write that electronic organs are a pipe organ "erzatz" which can solve some particular services.
Organs for students, transportable organs, etc...
But one must firmly reject these organs for churches, conservatories, concert halls, etc...

Here is a summary of  several arguments :

1. Electronic organs using soundbanks are based on additive sound synthesis.
That is to say that sound intensity represented by electric voltage at time t for each stop is added in order to achieve the final sound.
But this add has absolutely no relationship with what is really happening in real pipe organs.
In fact acoustic pressure p(t,x,y,z) at time t and at x y z position  is the result of extremely complex phenomenons which can be completely and rigorously
solved only thanks to the differential wave propagation equation.
This pressure is nether, in any case, as simple as an add of pressures genereted by each pipe of stop j sollicitated at time t.
Neither brand new computer can solve in real time such an equation. Nor able to simulate such natural interferences.
Therefore the soundbank VPO principle itself is at the very beginning in default.

2. Distortions :
There is an excellent webpage related to this topic.
http://www.pykett.org.uk/EndOfPipeOrgan.htm#Electronics
It shows that distortions which are void on real pipe organs exist on sampled virtual organs.

3. Absolute errors on additive synthesis using sounbanks :
Assume an organ  whose N stops are on, and n keys played on the keyboard. Let e the coding error codage. (For example e=1bit for a 16bits un sample)
The absolute rror will be : N*n*e.
Let for 20 stops and 10 keys simultaneously actionned with e=1 : 200 bits.
So we have a relative error of : 200/64000 = 0,3 %.

4. SPEAKERS :
Speakers are only vibrating, they don't are sending air flow as pipe organs are doing. No air is eshaled as human beeings.
Moreover speakers must suppot  the load formed by the sum of all stop sounds. On the contrary, each pipe has his role and his specific frequency.
So speakers can generate unwanted intermodulations and aliasing effects.

5. PRICES:
At present, one can purchase free vpo softwares. But malignant merchants are selling such virtual organs for churches at huge prices, with huge soundbanks, 24bits samples, huge RAM memories : Example in Cassis (near Marseille) : 60000 €. Instead of that, a nice medium size pipe organ could have been done. But this case is seldom.
Moreover, 20 years later, nobody will be able to cure such organ eszatz.

6. SPIRITUAL POINT OF VIEW :
There is a strong relationship between human breath and pipe organs. Organbuilders are using  some words such as "voice", "sing", "lips" and so on. For designating some pipe characteristics. "Spirit", "Spiritu" (in Latin language), and "Breath" (souffle in French) have exactly the same roots. The pipe set in an organ has also reletionship with humans, where there is a so diverse kind of mankinds ! But in an organ, all are according themselves for the beauty of song. And beauty is the face of God.

It's not the case concerning sounds produced by speakers with only a too simple electronic additive operation !