Loudspeakers for a Hauptwerk organ

Speakers make the sounds of the samples of a Hauptwerk organ audible. This is also the only match with all other audio applications. For Hi-Fi use is it important that the sounds from the lowest to the highest frequency are conveyed linear.

For optimal audio reproduction it is good to make these demands in the expectation that a concert in the concert hall will be transferred to a living room as the visitors it have experienced. A CD of this concert must fulfill the same requirements. The sound director ensures that all instruments are set in the right conditions. If the audio  hardware processed these sounds linear the speakers will transmit a good stereo image, where each instrument is in place.

Developing perfect speakers is a process of intense experimentation. There are large differences in the structures and each brand has found his own solution for all problems. Each manufacturer of speakers presented the features of their products as the most successful representation of the original sound.

 

Voicing

Many organists install a sample set and use this without adaptations, but who has heard the difference with a good adapted set will no longer accept this view. Thousands of pipes are made by me and I voiced them piece by piece. Adapting the samples is much easier and should not be compared with pipe voicing. Because I have an absolute pitch, which is additionally trained through the many voicing’s I made, I can quickly set the correct voicing. I photographed the positions of the sliders of the voicing of various organs and printed them in a booklet. These booklets are free to apply.

It was proved that a faithful copying of these voicing’s is always a large improvement of the sounds of the organ. The best result is achieved by listening and learning of the way the sounds change, so that a feeling is developed for judging the sound. After some time it is clear where the sound is optimal according to your own taste.

 

Surround samples

A third series of recordings can provide a surround sound in the sample set. Sounds that are recorded back in the church must be replayed by loudspeakers at a large distance from the Hauptwerk organ. These are sounds that an organist at the console in the church never hears. When replaying through the Hauptwerk organ, it makes no sense to make these sounds hearable for the organist.

On a surround recording of an orchestra you can sit in the middle of the audience, but when an organist plays the organ, he sits close to his instrument. The problem will not occur with surround sound in small churches, but in a large church as the Church of St. Walburgis in Zutphen, the gap is very large.

Sometimes, my help was asked by people who had spent much time to build up a large Hauptwerk organ with a large number of sound channels and often speakers hidden in a housing with fake pipes. They were disappointed because they had not reached the expected results. Then they found it hard to take my advice to replace the larger number of channels by only two direct channels close to the organist and two channels at a larger distances for the acoustics. But it turned out to be a huge improvement and the organ sounds rather like a church organ. All samples were recorded in two channels and a two channel playback sounds best.

Bass sounds

Another chapter is the reproduction of the low tones. This sounds are not displayed in both channels, but go to the subwoofer, which usually gets a place in the lower part of the console. It cannot be heard from which directions the long waves of the low notes are coming. For the bass channel just one channel is sufficient.

Two channels for the acoustics

On a larger distance from the pipes, two microphones are placed, which are meant to record the sounds in the acoustics of the church. They are stored as WET samples in addition to the DRY samples in the sample set and can be played by two separate speakers. So a 4-channel equipment reproduces the organ sound as well as the acoustics in good relations. 

I can provide the hall by a Lexicon MX300 and two sound channels. It sounds often better than the reverb, which is stored together with the acoustics in the samples. Both possibilities are used by me.

Reproducing via two channels

With two microphones, preferably placed at a short distance from the organ, the sounds are recorded with little reverberation. The recording is two channel. At home the best reproduction is got with a two channel reproduction. Two speakers as close as possible to the organist, as if he is connected directly by audio channels with the church. Each sound of the organ is recorded at the same position and all sounds must be replayed at home from one position. As if the organist is not at home but at the console in the church.

No more sound channels

The distribution of the sounds from the DRY samples across multiple channels gives no more organ experience. The benchmark to compare is my chamber pipe organ, this organ has a comprehensive disposition grounded on a complete Principal 8'. When the sounds of a church organ are reproduced on a Hauptwerk organ in the living room, this church organ has become a chamber organ, whose volume couldn’t be more than the size of a living room can bear. A large living room has more capacity than a small side room, because the dynamic is closer to a church, but no room can better reproduce the church organ by using multiple sound channels. A turbidity of the sound is the only result.

Should the organ be used in a space with the dimensions of a large hall, such as a small church, then, the circumstances are different and there are other rules. Several speakers are necessary for a sufficient acoustic energy. But in a living situation it is always superfluous.  

My experiments are tested in the laboratory of a German University by a scientist together with some experienced concert organists. The results are in line with my experiments.

 

Hauptwerk or Orchestra

When playing a concert the sound sent to the speakers are of instruments which are recorded all at the same time. The instruments are distributed across a wide stage and the sounds are coming from the direction where the various instruments were located. The speakers can give a reproduction of the stage by transferring a broad stereo image.

Pipe tones for the samples are recorded separately from each other and they are stored later as evenly as possible according to the judgment of the sample editor. Although all sounds are recorded with two microphones on a firm place in stereo, it isn't meant as a real stereo reproduction, where the direction of the sounds can be determined.

  Luidsprekers
    voor een  Hauptwerkorgel

Speakers at short distance

Two speakers at ear level, left and right of the organist give the best transmission of sounds of the church organist at home.

In a good sample set, the sounds in the vicinity of the organ are recorded and stored as dry samples. There are sounds such as the organist in the church them hears at the console. These sounds must reach the ears of organist at the Hauptwerk organ as directly as possible. They are best transferred through a good set of headphones. Prof. Helmut Maier is a strong supporter of it. There are two reasons to refrain from the use of headphones: no one can listen in with the organist, and there is a strong risk of hearing damage.

The big difference between the playing of the orchestra and the playing of the organ is its width. An organ is only a musical instrument and even a large organ is only one sound source. Because of practical reason an even distribution of the weight, the pipes are spread over a C-chest and a CIS-chest. That the notes jump then strange back and forth it's not enjoyable to play and therefore the case has as a main function to emit the sounds in one large area.

If the pipe scaling of the different registers are well tuned on each other, the sounds will blend in a consonance and they are emitted evenly across the entire width of the organ case. A stereo recording displays the width of the sound field, but the places, where the pipes are placed is not localizable. Therefore, the organ case has the function to mix the sounds and to beam them off in the area.

   Lautsprecher
     für eine  Hauptwerkorgel