Realistic Organ playing
In January 2019, the sounds were recorded in the Martini church and a year of work was done to make it the best sample set ever.
The pipes are voiced into the acoustics of the church and because these acoustics are for sale as convolution reverb, sound and acoustics form a perfect combination.
It makes the organist in the living room feel like he/she plays the organ in the church.
Convolution reverb    the best reverberation of a church

The basis of convolution reverb consists of a recorded sample of a room with good acoustics. A kind of acoustic footprint what is called Impulse Response (IR). The sample is obtained by producing a short and strong sound in the middle of the church, for example of an alarm pistol. The sound is reflected several times through the environment and slowly dies out. Around the source of the sound are a number of microphones that send the reflected sounds to the computer. The computer calculates the processes of extinction at each microphone and stores the reverberation behavior of this space in a digital memory. Every sound send through that memory sounds like it's been played in this room. It is a digital copy of the acoustics of the church.

To capture the pipe sounds in a sample set, multiple recordings per pipe are made. Microphones close to the pipes capture the direct sound in the DRY sample and microphones at a larger distance capture the reflections in the acoustics in the WET sample. It is not the ideal representation of how the organist hears the sounds in the church.
The organist is close to the pipes and hears the direct sounds there. From the same place he hears the reverberation in the acoustics of the church. Because the Hauptwerk organ in the living room uses the acoustics from the WET samples, so recordings taken at a larger distance, it sounds as if the organ is placed at a larger distance from the organist.
This evil does not occur with convolution reverb; the direct sound of the DRY samples sounds at close range and the reverberation is observed from the same place. That corresponds to reality.

Hauptwerk 5 is equipped with convolution reverb and that gives the organist the realistic feeling that he plays the organ in the church. Compared to Hauptwerk 4, this is the most striking and valuable improvement.

Sonus Paradisi has turned several churches into a reverberation recording and can be downloaded from the website. Per reverberation it costs between 10 and 30 Euro (order for 50 Euro (without VAT) or higher).

How IR's can be used

Impulse Response use is covered in detail in the Hauptwerk User Guide chapter "Audio routing and impulse response reverb, part 1 and part 2". In short:

1. Open the Hauptwerk Audio Mixer.
2. Select the desired bus to which you wish to apply the IR.
3. Click the Select button. It takes about 10 seconds to see the list. Impulse response reverb.
4. From the list of available IRs, select the one you wish to apply to the bus.
5. You can adjust the pre-delay, wet-mix and reverb-level if desired. For best results, use small adjustments.

Select bij View: Audio Mixer Routing and Voicing/Panning Settings for adjusting the volume of the reverb.

How to select the appropriate IR
Impulse Response (IR) is a footprint of the acoustic characteristics of the given space (church). IR can be used to reproduce these characteristics and add them to an input signal with the help of dedicated software (such as Hauptwerk‘s convolution reverb module). The most distinctive acoustic characteristic of a space is the reverberation time (i.e. how long it takes for the sound to die away). Therefore, the IRs described in this guide are ordered according to increasing reverberation time. However, there are other features according to which you might choose your favorite IR.

RT, T20, T30 - Reverberation time (RT) is defined as the time needed for the sound to decay 60dB below the original value.

The reverb time depends on the frequency
Each frequency band will die differently. Usually very high frequencies die very quickly, the maximum RT is somewhere between 500-2000 Hz. Each IR description contains a graph showing the frequency decay for different frequency bands. The colors indicate the intensity of the sound: yellow = high energy, red = less energy, violet = low energy, black = no energy (background noise). See pictures Martini and Michaels

Sonus Paradisi - Impulse Response (IR) User Guide

To install Impulse Responses, follow the process described in chapter "Installing/un-installing/upgrading organs, temperaments, or reverbs (the component installer)" found in the Hauptwerk User Guide. In Hauptwerk, installing an IR is similar to installing an organ or temperament. In short:

1. Start Hauptwerk.
2. Select the File menu, and then select "Install organ ...".
3. Hauptwerk opens a dialog box. Navigate through the directory tree to the installation package, and select the installation package you have downloaded.
4. Hauptwerk unpacks and installs the package. Confirm installation when prompted by Hauptwerk.
5. If there are more installation packages, repeat steps 2-4 for each remaining installation package. If you have purchased many IRs in one order, there will be many small installation packages. It is necessary to install each of them, one by one, to Hauptwerk.               Impulse Response Sonus Paradisi     PDF