Hauptwerk or simulation?

The Czech Republic is home to the company Sonus Paradisi, whose owner, Jiri Zurek, graduated after university studies on making samples of organ sounds. He does that full time and his skills in that area are not surpassed by anyone.
The samples he made for Hauptwerk can represent the tones of organ pipes with all characteristic properties completely equivalent.

There is a second company for organ sounds in the Czech Republic, Jakub Mlnarik. Not for sophisticated samples, but more intended for amateur players who only know an organ from listening downstairs in the church. Under the name Cecilia he delivers sets with simulated organ tones that do not show all the characteristics of pipes, but sufficient for the players who do not set high standards.

First a clear answer to the question I received several times: is there a difference between Sweelinq and Cecilia? No; Cecilia and Sweelinq and also LiVE are corresponding simulation programs. Minimal differences may occur in the application, but none of these programs show the tone of an organ pipe. Because nothing is transferred, the loading time can also be extremely short.

Cecilia is simulation software, which can be downloaded for free.
Adapted, low-priced sample sets from Sonus Paradisi are available for this purpose.
Four sample sets are free to: Kdousov, Doesburg, Velesovo and Menesterol.

Zurek gives the organist an honest choice:
1. Hauptwerk: Real sounds that are no different from pipe sounds - pricey system
2. Cecilia: Simulated sounds like an electronic organ - cheap system


Noorlander does not give that choice. He has set Hauptwerk aside and provides all his organs with Sweelinq, which, like Cecilia, is a system with the simulated tones. Only a tiny part of the recording is used that is played repeatedly in a loop, as long as a key remains pressed. That repeated tone sounds rigidly like an electronically induced tone. To mask that rigidity, Noorlander has the volume undergo rapid changes and he calls that the wind model, although it does not correspond to the fluctuations of the wind in a pipe.

In a church organ, the tone of a pipe is not constant, the wind is subject to swirls and that can be heard in the tone. This corresponds to every wind instrument of an orchestra; those swirls are peculiar to wind instruments. It is the natural vibrancy of a musical instrument. That liveliness is lacking in electronic instruments.

In my younger years I experimented a lot with electronic organs. To break the rigidity of the tones, I used a circuit that simply, but very effectively, showed the fluctuations of the wind in a pipe. In the last period I experimented together with Ir. Nico Franssen in the Philips Physics Lab. in Waalre. He convinced me that real organ sounds can only be achieved with pipes. After that I followed the pfeifenorgelbau vocational training in Germany and I became a professional pipe organ builder.

Nevertheless, I followed with interest the developments of the digital technique to produce organ sounds. Real progress was made with recordings of organ pipes. Decades ago, recordings of my pipes were made to add them as pedal toons to house pipe organs. Long shots copied the pipe tone best, because then all the properties of the tone were retained. The sounds of the pedal tones from the speakers were no different from the sounds coming directly from the pipes.

In well-recorded samples from Hauptwerk, the tones are transferred to the living room with their natural liveliness. Here the contrived effect of a wind model is superfluous. It is never used on my organ.

In Sweelinq an electronic organ can be heard, simulated tones without the sound beauty of a pipe organ tone. Sonarte will soon place here my new Hauptwerk organ. Then everyone is welcome to play it and judge the pipe organ sound for themselves.

Organists who gave a concert on a Sweelinq organ on behalf of Noorlander, he asked to express their opinion about the sounds in words. They said: I am enthusiastic - pleasantly surprised - a pleasure for the ear - very realistic sounds - better than Hauptwerk.
                 In this way, professional organists throw away their credibility and reputation.

 SONARTE     custom made organs

I found an organ builder with expertise: Wim de Borst of Sonarte in Capelle aan den IJssel.
Organist and organ maker who took organ lessons from his early childhood and had also studied how the sound in the pipe was generated. I was delighted to meet someone in Wim de Borst who applies the traditional handcraft to making Hauptwerk organs. The design is made after an extensive conversation with the organist, in which he (she) can make the wishes known. The organ will then be built exactly according to these wishes.

For my organ I wanted to have an audio system, which does not impose any restrictions on me when voicing the samples. In the organ, the tones of pipes are stored as samples in a digital memory. When playing, the digital-analog converter (DAC) ensures that the analog tone, which becomes audible through amplifiers and speakers, is the equivalent of the tone of the pipe. For all parts I have chosen the highest quality on his advice.

Stopped Diapason of wood

I have often made a Stopped Diapason of wood and I have experienced that in the living room the sounds of this register come into their own. In a house organ, the Stopped Diapason is never missing and it was already the most used register in the cabinet organs of 200 years ago. The tones have a beautiful Gravity, but I have not yet heard a Hauptwerk organ that could reproduce the sounds with this Gravity. There are sample sets in which the sounds of the Stopped Diapason are well stored, but the audio part of the organ must have a good quality, to reproduce them equal to the pipe sounds.

With this organ I have the confidence that it is possible to make the sounds of the Stopped Diapason sound with their Gravity. A beautiful Stopped Diapason is the most difficult register; when the Audio of my new organ can reproduce that, Principals, Violas and Flutes will sound fantastic too. Reeds form another chapter, but with the chosen audio I will be able to reproduce those sounds in a refined way.


The housing in which the speakers are mounted ensures an optimal reproduction of the tone area of the Stopped Diapason. Placing these in the organ case would affect the reproduction and that is why I put them on the case. That is also the best place, because there are at the heights of my ears. I have made a preliminary design of the cabinet, which is shown above. It is not a photograph, but a montage of a large number of parts of Sonarte organs.