muis toont de wervels
Pipe sounds from Samples

Many years was designing organs for the living room my speciality. The pipes of a church organ are not suitable in the living room, but it is possible to get the same sound if the pipes are made especially for the living room. The diameter scale remains the same, but with a lower wind pressure and a to the lower wind pressure adapted upper lip, the sound is made less powerful and the pipes will produce the same sound spectrum. Each pipe (sound source) must be voiced in the living room.

Samples contain the sounds of church organ pipes, that now at a lower volume let hear a completely different sound. It corresponds to the church organ pipes which are not usable in the living room. Again, an adjustment is required to listen to the same spectrum of sounds. Hauptwerk offers all possibilities to facilitate this adjustment.

The sounds will be played with speakers, but here, the speaker has a completely different function than when its playing the sounds of a CD. The specifications, which express the quality of the speakers, are based on representing an evenly and colorless wide range of the audio spectrum, but says nothing about the application in a Hauptwerk organ.

Hi-Fi audio-technology has no advantage for Hauptwerk

The apparatus for the reproduction of sounds must have high quality to make the recorded sounds are heard in the same conditions. As higher the quality of the audio technology is, as better it fulfils his task. So a perfectly smooth playback can be achieved from 20 Hz to 20,000 Hz but for a very high price.

In a sample set, each pipe of each register is recorded several times. The sample editor evaluates the large amount of shots (all recorded separate) and corrects them where he thinks it is necessary. He has no objective standard of what he might consider his sounds. During playback, the local situation of the environment and the lower volume of the sounds makes it necessary to adapt the samples per piece. Any deviation in the playback can be optimized separately per tone, even per overtone. A completely level playing is pointless here, showing thousands of audio sources with big differences.

At several organists I have adapted the samples under different conditions. Good active speakers (bass + treble speakers, including amplifier) plus a good subwoofer are sufficient for an optimal playback of the sample sets. By customizing the samples piece by piece I got anywhere the same sound. The quality of the speaker played only a limited role.

The size of the room where the organ is played, proved to be an important factor. It is impossible to play the Sample Set of an organ from a cathedral in a small room to hear sounds that give the illusion of a large church. This result is easily reachable in a large room, also with audio devices that do not belong to the top class.

photo shows the pipes of my chamber pipe organ

NormMensur (Scale list)

As long there are organs, the organ builders have searched for the most beautiful sound. It depends off their ability to bring the pipes to a harmonic affinity, where a certain uniformity was sought from pipe to pipe. The length of the pipe determines the pitch, but the sound is dependent on the diameter. The course of the diameter is listed in the scale list and is a determining factor for the sound of the organ.

At the beginning of the last century the organ builders found that a standardization of measuring cylinders was important. The German Orgelrat (Organ Council) concluded that the pipe on C large should have 155.5 mm in diameter and named this the Principal standard pipe and used this as the basis for the NormMensur. Calculated on the basis of the ratio 1: 1,682 an evenly-sounding scale, where all Principal pipes have the same volume audibly.

Coloring gives the organ sound its beauty

In this way the organ builders could produce pipes at all pitches with a uniform sound impression. Neither the bass pipes nor the treble pipes provided each other, a good balance was achieved. Although the NormMensur makes a uniform volume possible, it was hardly applied.

Perfectly evenly is also dull and musically not exciting. An organist would rather prefer a sound with a color gradient to the dark tone color or a gradient for more clarity. Definitely a colored sound must be heard. A dye, which an organ builder with a good sense for sounds could attach to his own taste. He will then vary within certain limits of the NormMensur.

A for any organist comprehensible method for the adjustments of the samples is described with text and many photos in the Hauptwerk Practical Guide.

Everyone who requested the Hauptwerk Practical Guide gets it free, but I ask to inform me about the results. I use that in new editions of this book, so I keep the book always up to date and add it to the knowledge of all the users.

Free to request with a mention of the E-Mail address and the complete postal address.
                                                           John Boersma

      A mouse click on a book leads to the page about the sample set
Voicing the organ pipes

By voicing a pipe of organ, the sound is attached which the organ builder had in mind with the design. Usually, the designer is also of the voicer and also the manufacturer of the organ pipes. 
The wind flow is determined by the foot opening and the core gap. They mutually influence each other and the voicer is looking for the balance between them. The wind flows to the upper lip what caused a vacuum inside the body, which draws the wind flow inside. The result is an overpressure inside of the body, the wind current pushes out again; the cycle repeats itself and the wind swirls around the upper lip.

In this way it generates a sound that brings the air column in the pipe in the response. The location of the languid determines the angle that the wind approaches the upper lip. This is different at a Silbermann pipe to a large extent of a Schnitger pipe. All of these factors are of great influence on the sound and a voicer must master them all to make the sound, which he had in mind while designing the organ.

If the pipe produces the right sound, the next pipe must be treated in addition in the same way to generate the same sound, but with a difference in pitch. The sound of a register changes depending on bass, tenor, alto or soprano.

For the voicing of the pipes is not only knowledge needed, but also a great skill. It will take years before someone has enough experience to be able the voicing.

Voicing Samples

Customize the samples is also called voicing, but that has no corresponding match with the voicing of a pipe. The adapting of the samples is a simple thing, it is to explain in writing and to learn quickly. My first book about the voicing is sent to 450 people in all parts of the world. Many people have reacted to inform me of their experiences at my request. The adjustment of the samples was well understood, sometimes with another statement. These explanations are all processed in the new edition.

An important condition is that the organist knows the sound, that he can expect of a Hauptwerk register. This knowledge is only to get by playing many organs in various churches. The sound that he seeks must be in his memory, otherwise he has no goal to work towards.

A sample forms a entirety with the speaker

For Hauptwerk, it makes little sense to use amplifiers and speakers, which provide an even reproduction of an audio area till 20.000 Hz. The sounds are recorded per pipe in the church and are reproduced under different conditions in a domestic environment. The lower level, the characteristics of the speakers and the homely environment are the cause, that the sounds are reproduced unevenly.

The samples must be corrected per piece to offset the mutual differences. If a uniform representation of all sounds is preserved, the speaker forms a unit with the samples. Various properties of the speaker determine the price, an even reproduction of all pitches increases it substantially. That will not bring better sounds in a Hauptwerk organ as with speakers from a low price range. An equal reproducing is here not dependent on the loudspeakers, but on a good correction.

Replacing the loudspeakers, means adjusting all samples again

The method to make this adjustment is described in the Hauptwerk Practical Guide. It describes everything an organist must do to make the sounds identical to the sounds in the church. Off various good sample sets the corrected settings are photographed. These books are free to request too, on condition that you are willing to share the results with me. See at the bottom of this page.  

Free to wear with a mention of the E-Mail address and the complete postal address.

                                                                                                          John Boersma

Samples intonieren
      auf Deutsch
Transparent Sounds – Basis of Voicing

While voicing the pipes the most important rule is that the sound remains transparent. The art of the voicing is a balanced distribution of the volume (amplitude) and the clarity (brightness). At the bass tones in the CC octave and the lowest notes of the c0 octave, the force must be voiced restrained.

32 Foot Register - not possible in a chamber

Only in extremely large churches there are 32-foot registers; an immense large space is needed. However, sample sets with 32-foot registers are offered for use in a living room or a study; even from church organs, where this 32 foot not was planned (Steendam organ in Apeldoorn by Sygsoft). Many organists seem to have the desire to play a 32-foot register. In a church organ it is a precious register, in a house organ it is an impossible register. It is physically not possible to reproduce these low sounds in a room.

However, the wavelength of 16 Hz, 330 (m/sec) divided by 16 Hz 20 meters. If this distance is not available, the tone cannot develop. The human ear has the property that if a sound the tone is not given back, the second or third overtone is perceived. The organist believes to hear the 32 foot show, but it's nothing more than a disorderly sound. Who once used a 32 foot register in a large Cathedral, will immediately notice the difference: this sound is a soft, velvety bass sound under the 16 and 8 foot bass register.

 Samples intoneren
Sounding samples like Pipe tones

The typical characteristics that show the character of the pipes is always too weak recorded in the samples. This abnormality must be corrected with the transient. Of course that the speaker must have an impeccable quality, but even the best speaker is not capable to represent the real sound of the pipes without a correction of the transients.

In the Hauptwerk organ, every sound (sound source) can get its own correction. A large number of owners of a Hauptwerk organ I helped with voicing their samples. I have experienced that always a good correction is necessary, regardless of the quality of the speakers.

The tonic of f3 of the Octave 2' is 5588 Hz, an overtone is absent or very weak. These small pipes produce only sine tones; a great skill in the intonation is already necessary to make this sound good. A one foot stop at this point don’t higher, since it is repeated here to an octave lower. Both pitch and manufacturability of small pipes set limits here. The sounds of the mixtures and cymbals need a large space.
A Hauptwerkorgan offers this acoustic space, that is not really present in a living room.

Audio playback higher than 10,000 Hz is so pointless; these tones will not be found in an organ. Also not in the reeds, where the sound, as the Principal, is determined mainly by the formant. Formants amplify the resonance of the characteristic tones; they strengthen them and weaken the tones that fall out of the formant.

Since there are no high tones in an organ, organ builders until very old age are good to practice their craft.

The booklets show the positions of the voicing sliders of the samples. After my voicing I have compared the sounds to the original organs.  

The books are free to free request with the full postal address. 

Send an e-mail to:

                                                John Boersma
Hauptwerk User Guide

The program Hauptwerk is supplied with the User Guide. It is an incomprehensible book; just the technical jargon of the producers of Hauptwerk.

Every day I write and read English and I have no problems with that language, but studying the User Guide didn’t gave me the information that I needed for getting know the Hauptwerk program; it is not a manual. Since there are no further publications about Hauptwerk, only one possibility is left: to try actually in practice any operation of the book. Sometimes, the organ was completely disturbed and I had to go back many steps to see what had gone wrong.

I've found all the procedures and I can explain it in understandable texts and images. Step by step I learned all about Hauptwerk in practice. That I described in the first book about Hauptwerk, which has become a real practical book. To translate this book into German and English was the next step. I posted this free available on other users and asked them to inform me about the results. With the comments I wrote the book several times again, to keep the information up-to-date.

The intention of Hauptwerk is: playing a church organ in the living room. If it should sounds really good it is especially important to have knowledge about the behavior of sound in the small space of a living room. As I am an organ builder specialized in chamber pipe organs, I have gained a lot of experience. In the User Guide, there is nothing to find about it. The source of the sounds are the samples; here the sample makers have stored the pipe sounds. The organist should voice the samples on his Hauptwerk organ to play the sounds of the pipes in his living room in accordance with the sounds in the church. The working procedure is described in detail in the Hauptwerk Practical Guide and there are special editions of successful made sample sets.