Hauptwerk 5  - the virtual organ

Amateur organists who want to buy a Hauptwerk organ, seldom have experience playing a church organ. They only know the sounds they heard in the church at a great distance from the organ. Sample sets often contain sounds that are also made far away from the pipes as WET samples. More reverberation can be heard at that distance. Since amateurs are not familiar with the practice of playing church organ, the sounds of the set match their expectations. However, an organist cannot make music with it. He wants to hear the sounds very close and then experience the reverberation when those sounds die out in the large space.

The organist knows the real organ sound. A key press immediately makes the pipe speak with an accent on the beginning, after which the tone builds up to full strength. It is the articulation of the tone with which the organist makes music through his play of rhythm and phrasing. The pipe tones are heard at a short distance by the organist, then the reflections hit walls, columns and other objects that are increasingly distant, making them fainter and dying out in the distance. The reverb moves away from the source of the sounds. That is the sound experience of the organist, who must reproduce the Hauptwerk organ in the living room exactly like that.

An organist can only make music with a Hauptwerk organ when the tones are heard at a short distance. Therefore, the samples must contain tones that have been recorded at close range, so DRY samples. Also the reverb may not be imitated by WET samples, that is not the reverb that he hears when playing in the church.

In Hauptwerk 5 a new technique has been realized, in which the church acoustics with an Impulse-Response recording is stored in the memory of a Hauptwerk organ. Now the situation is completely in line with the church. The tones that die far away in the large space give the organist the same sound experience as in the church.

 with the DRY samples of the organ in Groningen and the IR reverb of the church it can be heard perfectly

Surround was popular in Hauptwerk 4. This required many channels with WET samples and a room full of speakers to reproduce those sounds. Surround for a film shows how a car moves through the screen or how someone walks on a gravel path. Audible movements support the visible image.

However, an organ remains in place. The case of the organ bundles all sounds and lets them come out as one source. Two channels are sufficient for the sounds to be heard in stereo. The reverberation from the Impulse-Response produces an immense space. Where surround was used to imitate that space, the IR reverb realistically reproduces that space.

A church with good acoustics

The sounds I hear in my living room are the same as what the organist hears in the church. Two channels that together form a single stereo channel are sufficient to display the organ in the church, which is even one source of sounds, in the living room. The function of the organ cabinet is to bundle the sounds into one source. It is impossible to determine where the pipe is at that moment. A distribution of the pipes in C- and Cis side is done to distribute the weight of the organ, but a good organ cabinet prevents the direction from being audible. There is only one source of sounds. If the acoustics of the church are good, the whole room will be filled with sounds, without an apparent direction.

As example the two organs of Bedheim (East Germany). They are placed in two organ cabinets, one in front of the church and the other hangs at the back like a Swallow nest organ on the ceiling. The two keyboards are in the main organ. The sounds merge completely and in no place in the church can be determined from which organ they come from. The acoustics unite the sounds into an all-around sound.

As a pipe organ builder and voicer, I have played the organ in hundreds of churches in Europe. I know the specific differences between North and Central German organs, as well as the Swiss and Italian organs. In all these styles I have made pipes and voiced them to the sound of that style. When DRY samples have been made of these sounds, I can also voice them and there is no difference with the sounds of that organ in the church. To display my Hauptwerk organ, I use one stereo channel with DRY samples and the reverberation recorded as Impulse-Response.

According to Silbermann, the organ sound is a balance between Power, Clarity and Poetry.
A Principal plenum will sound powerful and transparent and fill the entire space. The poetry can be found mainly in lovely tones, such as a four-feet Flute that sounds thin in a seemingly limitless space. The sounds are present all around and do not seem to come from a certain direction. This is the realistic representation of the church organ that cannot be matched with multichannel WET samples.

Organists who rejected Hauptwerk after hearing a Hauptwerk 4 multichannel organ, played my organ with enthusiasm. The sounds and reverberations are heard in the church. Moreover, my pipe organ is next to compare the sounds. Unfortunately, the house pipe organ lacks the necessary reverberation, making the Hauptwerk organ preferred.

book Martini
Characteristic sounds

The most important part of a pipe tone is the beginning, the moment when the pipe starts to form its tone. It is the articulation that the organist needs for his musical expression, as is the case with any musical instrument. When the wind from the languid gap reaches the upper labium, there is an underpressure that draws the wind in. This results in an overpressure in the pipe that pushes the wind out again. see Prestant

This swirling wind gives a clear asccent to the tone. The accents differ according to the nature of the register, a Principal starts differently than a Stopped Diapason. The microphones must be a short distance from the pipes to capture the character in the DRY sample or the important part of the sound will not be heard. Sometimes it is not possible to get the microphones in the ideal place and it becomes a semi DRY sample, but with the wide possibilities that Hauptwerk offers to adjust the sounds, the articulation can still be heard.

In normal playing, the articulation and the first moment of tone formation is the only thing that is heard from the organ sound. It is therefore important that this is properly recorded. I have played a lot in churches in southern Germany and in Switzerland with a huge reverberation and then the acoustics of the empty church are were annoying. Then I am happy that the church fills up and dampens the acoustics.

I made the convolution reverberation of my Hauptwerk organ adjustable with the left pedal, so that it can always be adjusted to the music.