WET samples are recordings from microphones placed at a great distance from the organ. Due to the time difference between pressing the key and hearing the pipe tone, the typical properties of the pipe tones cannot be heard. The tone comes at the listener from afar. A big difference with the organist in the church who immediately hears the tone. That is necessary to be able to play. Amateurs who only know an organ tone from listening to it in church do not know that it sounds completely different with the organist.
How the reverb functions
Playing in church
As soon as the pipe gives a tone, the first reflection against the nearby walls and columns immediately follows, followed by reflections against objects further away. These reverberations make the sound wider and fuller until it dies out in the distance. This is essential for playing an organ, the organist sits at the source and only from this place can the swelling of the sound be heard.
Playing in the living room
If the organist at home on the Hauptwerk organ wants to experience the same as the organist in the church, tone and reverberation must undergo the same process. This is possible with DRY samples, because they are recorded close to the pipes and reverberation from an Impulse Response recording, because Convolution creates a copy of the acoustics of the church. This gives the tone from a DRY recording a swelling effect.
Large files
In a DRY recording, the complete behavior of the tone formation in the pipe is recorded for 10 - 20 seconds. Striking staccato or legato reveals different behaviors of tone formation. This is all recorded in the sample and therefore the samples form a large file. The only thing an organist notices is the time it takes to switch organs. But why would it make sense to change organ often?
Magnificent sounds with a deep Gravity demand a large memory space.
Two channels (stereo) of DRY samples reproduce the sounds that are exactly the same as the sounds heard by the organist at the console. With the acoustics from the Convolution Reverb, the church organ reproduces perfectly. Everything that is added to it is superfluous and detracts from the actual organ sound.
Surround
Surround gives adventure movies a realistic effect. A car that comes at great speed from the left and disappears to the right again allows the viewer to experience it completely. Pipes, however, tend to stay in place. Only when I sit inside the organ case for voicing pipes do I hear in which direction I can find them. This cannot be determined outside the organ case; the organ case has the function to mix all pipe tones and reproduce them as one source of sounds. A division in C and C-sharp drawer has been done to evenly distribute the weight of the heavy pipes. But the case of the organ has the task of mixing all sounds and making them audible outside as one source of sounds.
Two organs in the church of Bedheim
In Bedheim (East Germany) there is an organ in the front of the church and an organ in the back of the church. The console of the organ in the front of the church has a second keyboard to play the organ in the back of the church.
The acoustics work so perfectly here that it is impossible to determine which organ is sounding. The stops of both organs can be used together. I chose stops from both organs to compose a plenum; the sounds completely merge with each other.
With surround, the speakers are distributed across the room. For each sound, the direction from which the sound comes can be indicated. The difference with a church is that good acoustics allow the sounds to be heard without being able to determine the direction; they are everywhere. Convolution reverberation from an IR recording is a full copy of church acoustics.
DRY samples and IR Reverb reproduce the church organ perfectly
An organist who listens with headphones does not get a good impression of the sounds. Headphones close off the environment, but in order to assess sounds they to must be listened in relation to the environment. Compare it to a painter who needs more than a light on the subject and one on the canvas. The entire environment must be brightly lit to assess colors and light contrasts.
In order to be able to assess sounds, the organ must be assessed in a space as large as possible. A small room is unsuitable for playing an organ. I have proven this statement with experiments in the audio lab of Philips in Waalre.
A high risk of hearing damage is another important reason to never use headphones. This has been shown by research by the Erasmus University of Rotterdam and the Catholic University of Leuven. A large volume heard close to the ear causes permanent hearing damage, but a lower volume heard over a longer period of time has the same effect.
The samples contain the loud sounds of the organ in the church; therefore listening with headphones will always lead to hearing damage. For an organist, his hearing is vital and it is unwise to use headphones. Hearing damage can occur in the form of poor perception of certain tonal areas, but Tinnitus (ringing in the ears) is more common. In all cases, hearing damage cannot be cured.
The samples of Organ Art Media are recorded by Helmut Maier from a great distance from the pipes and assessed with headphones. The user is expressly advised to also listen to them with headphones. He has stored the long echo tails in such a way that they cannot be shortened. His samples differ greatly from the original sounds and cannot be improved by voicing them. He does not want to use convolution reverberation. The conversations I had with him have not led to a better quality. I don't want to hear this mess and that's why I wrote off his sample sets and removed them from my Hauptwerk organ.
The book about voicing of Hauptwerk samples will be sent free of charge if requested with the
full postal address.
mail to: John Boersma
In order to hear each tone at home as it sounds in church, a long-term recording is made of each pipe. Due to the fluctuating wind, the tone is fluctuating, creating a lively character that sounds different with every pipe. The entire recording process is recorded in a digital memory – the Sample.
So a sample is a complete copy of the pipe tone. Every nuance of the tone played by the organist at the concert corresponds to the sounds he or she had already heard on the Hauptwerk organ at home. This way you can study perfectly.
In the church, the organist sits close to the organ and hears the tone immediately and at a short distance, even before the first reverberation of the acoustics occurs. This is followed by reflections at greater distances and the reverberation is created that makes the tones sound fuller until they die out in the distance.
The display on the house organ must correspond to this. The acoustics of the church have been transferred to the house organ via an IR recording. The tone begins a short distance from the organist, then fills up in the acoustics and dies out. Here too, the reverberations of the acoustics come after the sound of the tone in the same way as in the church.
All samples together form the sample set. It is a large file that takes two minutes to load to play. Then you can hear a perfect reproduction of the sounds from the pipes. Every nuance of the fluctuating wind is audible, revealing the liveliness of the tones.
The wind model is switched off, which sounds fake and well-recorded samples do not need these fake sounds. My pipe organ is next to the Hauptwerk organ and many organists have been able to compare the sounds to determine that sounds from samples do not differ from sounds from pipes. When comparing, Hauptwerk's acoustics were turned off and only dry tones were heard.
When the tones are recorded for a sample set, the fluctuations must also be stored in the sample. In post-processing it is the art of the sample maker to remove unwanted noise and overtones without affecting the fluctuations. Unfortunately, things often go wrong there and with the overtones, the fluctuations have also disappeared. Making samples of an organ is a difficult job, which requires the expertise of voicers of organ pipes.
The lack of fluctuations makes the tone rigid and that is masked by a technical trick. The amplifier that transmits the tone is modulated with a rapidly changing signal that varies the volume. The rigid tone with the fake fluctuations was named the wind model. For me as an organ buiilder of pipes it is incomprehensible that organists cannot hear the difference. Because it is an artificial effect, it gets boring quickly.
When I have installed a sample set, the first action is to disable the wind model. I only use sample sets from Sonus Paradisi and from Prospectum; here the original fluctuations can be clearly heard. Both sample makers belong to the top of Hauptwerk and their samples are closest to the sounds of a pipe organ.
Tones from pipes
When the wind flows from the languid gap along the upper labium, a negative pressure is created in the pipe, which pulls the wind inwards. The result is an overpressure that pushes the wind out. The effect of opposing wind currents gives a clearly audible accent such as an s or a k sound, after which the tone is sounded. It is similar to a vowel preceded by a consonant. As with speaking, a vowel takes on meaning when it is preceded by a consonant. This is an important effect for the organist; it gives expressiveness to the tone. He must hear it before the first reflection of the reverberation becomes audible.
Acoustics
The reflections in the acoustics create the reverberation that gives the tone more fullness. The reverberation begins as soon as the tone is heard and is repeated by reflections on increasingly distant objects. A sustained chord becomes audibly fuller due to the resonance, it takes on more brilliance and fills the entire room until the reverberation weakens and dies out in the distance.
In Hauptwerk, a copy of the church acoustics is made using Impulse-Response technology and stored in the memory of the Hauptwerk organ. This reverberation gives the tones of the DRY samples the same effect of increasing resonance as the acoustics of the church give to the pipe sounds.
A Hauptwerk organ needs two channels with DRY samples to be an identical copy of the church organ. The reverberation follows a different path and is merged with the sounds in the Hauptwerk organ.
from Impulse via Response to Convolution Reverberation = Copy of the Church Acoustics
Convolution Reverb
The correct way to transfer the acoustics of the church to the living room is to make a copy of the church acoustics. It is a method that every musician knows. Recordings were made of each music theater by sounding a strong Impulse and feeding the acoustic reverberations to a computer as a Response. It stores the acoustic behavior in a memory. Any sound that is played through that memory sounds as if it has sounded in that space. Modulating the sound on the reverb is called Convolution. In this way a musician can study at home in the acoustics of the building where he will perform.
Impulse-Response
Hauptwerk has Impulse Response recordings. Jiri Zurek has recorded IR reverb from a large number of churches for use in Hauptwerk. By adding this reverberation to DRY samples, the living room has the acoustics of the church. The tones from the samples then undergo the same effects as the tones from the pipes in the church, they become fuller and shine.
The organist recognizes the natural acoustics he is used to hear from the church organ.