Groningen, St. Martini

The history of the organ of the Martini Church in Groningen

St. Martini Organ

The history of the Martini organ dates back to 1450, when Master Hermannus built an organ and placed it in a new gallery. In 1482, the organ was extended with a Rugpositief by Master Johan then Damme from Appingedam. The consultant for that work was the humanist and organist Rudolphus Agricola. His name can be seen on the cartouche below the Rugpositief.

The organ case shows the year 1542, which refers to a rebuild of the organ in Renaissance style by an unknown builder. At that same time, the organ was expanded with a Bovenwerk. However, the Gothic framework for the organ case was almost completely preserved. Further additions were made around 1564 by Andreas de Mare and in 1627/28 by Anthoni and Adam Verbeeck. From 1685 to 1690 Jan Helman began extensive work including new bellows, keyboards and spring chests for the Hoofdwerk and the Pedaal, but he died in 1690 leaving some of the work unfinished. The parish then contacted Arp Schnitger, who completed the work left unfinished by Helman in 1691/92. Schnitger built large pedal towers on both sides of the organ and placed the 32-foot Principal pipes in the facade. The large pipes were made in the church, using ships' masts to help form them. The alloy for the front pipes has a high lead content. Schnitger also built three reed stops and a new wind chest for the Bovenwerk. Finally, he lowered the organ's pitch by moving all the pipes one step. By all these actions the organ received the signature of Arp Schnitger.

In 1728, Arp Schnitger's son Franz Caspar built new wind chests for the Hoofdwerk and the Pedaal, as well as a new Rugpositief including case, wood carvings, and console. Despite the long and diverse history of this organ before Schnitger's time, Schnitger's work is so profound that it is justifiable to say the organ of the Martini church is a Schnitger organ.

After the death of Franz Caspar Schnitger, additional work was completed in 1730 by Master Albert Anthony Hinsz. Then in 1739/40, Albert Anthony Hinsz installed seven new stop and thus the organ was enlarged to 47 stops.

In the 19th century, the Martini organ was adapted several times to the tastes fashionable at the time, and its disposition was romanticized (1816, 1831, 1854/55). The organ builders Lohman and later Van Oeckelen made modifications to many stops and extended the organ to 52 stops.The 20th century brought several big changes: a pneumatic action for the pedal (1904), the removal of the eight surviving wedge bellows in favor of a large magazine bellows, and in 1938/39 a new console with electric action for the keyboards, some new registers, and a new tuning. However, the original console was kept in place.

By the second half of the 20th century, organologists and organ builders understood that traditional organ building had to be re-discovered. Pioneering work was done by the organologist Cornelis H. Edskes in Groningen. He studied the well-preserved organs of the Baroque era, which still retained their original state. The organ of the Martini church was romantically voiced, but through restoration the organ could be returned to the Baroque sound of Schnitger. The organ builder who had great experience with such restorations was Jürgen Ahrend. Together, Ahrend and Edskes laid plans for how to perform the restoration.

The restoration of the organ by Jürgen Ahrend in Leer/Loga (Germany) happened in two parts, the first in 1976/77 and the second in 1983/84. The work included reconstruction of the mechanical action, the construction of a new wind supply, and the restoration of the wind chests. The old pipes were restored to their baroque voicing and the organ was returned to the disposition of 1740 – although some 19th-century stops are also preserved in the current instrument with an adapted voicing. Ahrend even reconstructed the original Speelfluit 4´, of which only a single pipe from 1542 was found preserved in the local museum. The organ now consists of 53 speaking stops. It is remarkable that the 32-foot pipes of the organ were repaired again in the church, and again ships' masts were used to shape the metal.

Wind pressure 80 mm
Pitch A = 466 Hz. (½ tone higher)
Temperament Neidhardt III

(text by John Boersma)

Special thanks to: Erwin Wiersinga, Henk de Vries, Sietze de Vries and numerous other nice people from the St. Martini church administration for their kind assistance during the recording sessions in St. Martini. Very special thanks to Sietze de Vries, who supervised the creation of the sample set, tested it and gave many useful remarks.



The samples are offered in 48kHz/24bit resolution. The model uses multiple releases, with three release levels: short, mid and long. Hauptwerk v7 and higher supported. The sample set is offered in encrypted format using Hauptwerk's proprietary encryption.

Reverb time

The reverb time is ca. 6 seconds.

Keyboards, pedalboard

The original compass of the keyboards is 49 keys (full 4 octaves), which is extended to 54 keys virtually via a dedicated switch. The original compass of the pedal division is 27 keys, extended to 30 keys virtually. Low C# of the Pedal sounds an octave higher on the original instrument. Proper low C# is available for all pedal stops virtually via a dedicated switch.


All ranks were recorded with and without tremulants where available for the most convincing tremulant behavior. The Rugwerk is affected by two tremulants, both of which were recorded. However, loading the sampled tremulant ranks consumes large amount of RAM. It is possible to use artificial (waveform) tremulant instead to save RAM (the switch is located on the mixer tab). You can choose to omit some or all of the sampled tremulant ranks when you load the organ the first time.

Pipe coupling effect

See the article for the explanation of the effect.


Screen resolution 1280x1024 px or more.

Polyphony of 8000 voices recommended for the full suround (4000 pipes minimum, 2000 for 2 channel variant).

Semi-dry variant

The sample set has several variants. The Semi-dry variant has been recorded very close to the pipes. It contains low level of the inherent reverberation. Hence, it is useful for loading with releases truncated to minimum, and impulse response reverb is used to place the organ virtually into any desired space. The samples for the semi-dry sample set are entirely different from the samples used in the surround variant!

RAM consumption: 2-channels (Semi-dry)

  • 16-bit, other settings default: 12.4 GB
  • 20-bit, other settings default: 20.3 GB
  • 24-bit, other settings default: 23.1 GB

RAM consumption: releases truncated to the shortest level (short decay) - for use with the Hauptwerk convolution engine and Sonus Paradisi IRs.

  • 16-bit: 8.9 GB
  • 20-bit: 11.8 GB

RAM consumption: releases truncated to the shortest level, all tremulant ranks disabled - optimized for the reasonable minimum RAM consumption

  • 16-bit: 6.0 GB
  • 16-bit: 4.2 GB when loaded in mono (for the absolute minimum RAM consumption)

Wet, 4-Channel Surround, Full Surround variants

The sample set is also offered in a Wet variant, a 4-Channel Surround variant, and Full Surround variant. These variants contain some or all of the following samples:

Front direct channels - capture the sound at moderate distance from the pipes, resulting in relatively direct sound with little reverberation. Note: These samples are different from the semi-dry samples, which are recorded very close to the pipes.

Front diffuse channels - captured at mid distance from the organ, where the sound had an excellent balance of direct and reverberated sound. These channels can be used alone for simple stereo applications, or as front channels for surround.

Front distant channels - captured at larger distance from the organ, so that the sound appears immersed in the reverberation. These channels can be used alone or mixed with the Front direct channels for more detail.

Rear channels - capture the acoustic response of the church, not the direct organ sound. These channels are good for rear speakers in a surround setup, or can be mixed into a stereo signal for a wetter sound in headphones or other 2-channel setups.

The Wet variant of the model includes only the Front distant channels.

RAM consumption: 2-channels (Wet variant)

  • 16-bit, other settings default: 12.4 GB
  • 20-bit, other settings default: 20.3 GB
  • 24-bit, other settings default: 23.1 GB

The 4-Channel Surround variant of the model includes the Front Diffuse and Rear channels.

RAM consumption: 4-Channel Surround

  • 16-bit, other settings default: 23.1 GB
  • 20-bit, other settings default: 38.9 GB
  • 24-bit, other settings default: 43.7 GB

The Full Surround variant includes all 8 channels listed above.

RAM consumption: 8-channel surround

  • 16-bit, other settings default: 46 GB
  • 20-bit, other settings default: 75 GB (recommended)
  • 24-bit, other settings default: 85 GB

Ram consumption: 8-channel surround, but all tremulant samples muted

  • 16-bit: 26 GB (useful for computers with a total of 32 GB of RAM)
  • 20-bit: 44 GB

In total, there are six front channels and two rear channels available. In the Full Surround variant, the front and rear audio channels can be mixed or used separately in myriad ways, depending on the preferences of  the user. A dedicated "mixing desk" is available in Hauptwerk to mix the sound  to the desired level of "wetness". Note: To reproduce the surround format, an audio card with at least 4 output channels is required, dedicating front channels  (in any desired blend) for the front speakers, and other  two channels for the rear speakers. 

The sample set is not mono compatible, loading ranks in mono is not recommended.

How to set the optimal sound of the 8-channel surround?

The answer will depend on the taste of every user. Following lines are a simple guide for those who feel lost among so many channels. Start with the Distant solo. On the Mixer tab, slide all sliders to 0, except the Distant slider, leave it at the default settings. Listen to the result. If you like it, you are done with your optimal setup!

If you would like to hear more room resonance, add some rear sound to the mix. Slide the Rear slider a bit up until you like the result. Let the Distant channels play from your front speakers, while the Rear channels from your rear speakers.

If you feel, that the distant sound is too "wet" for you, and you wish to have some more detail of the organ pipe speech, you have two options. Mix some direct sound to your Distant channels by dragging the Direct slider a little bit up, until you get the detail you wish.The Direct channels should play from your front speakers as your Distant channels.

Or, you can mute the Distant channels and use the Diffuse channels instead. The Diffuse channels can be used solo for practicing music. If you like the diffuse sound, you can use it solo, or, again, add the Rear channels to it.

If you require still more direct pipe speech detail, you can mix the Direct channels to your Diffuse channels.

Following scheme shows the recording positions for the samples of the 8-channel surround variant.


Rugwerk    .    Hoofdwerk    .    Bovenwerk    .    Pedal
Quintadena 16´     Praestant 16´     Praestant 8´     Praestant 32´ 
Praestant 8´   Octaav 8´   Holfluyt 8´   Praestant 16´
Roerfluyt 8´   Salicet 8´   Octaav 4´   Subbas 16´
Bourdon 8´   Quintadena 8´   Nasat 3´   Octaav 8´
Octaav 4´   Gedackt 8´   Mixtuur 4-6 st.   Gedackt 8´
Speelfluyt 4´   Octaav 4´   Sexquialter 2 st.    Roerquint 6´
Gedacktquint 3´    Gedackt fluyt 4´   Trompet 16´   Octaav 4´
Nasat 3´   Octaav 2´   Vox Humana 8´   Octaav 2´
Octaav 2´   Vlakfluyt 2´       Nagthoorn 2´
Fluyt 2´    Mixtuur 4-6 st.       Mixtuur 4 st.
Mixtuur 4-6 st.   Scharp 4 st.       Bazuyn 16´
Sexquialter 2 st.   Tertiaan 2 st.       Dulciaan 16´
Cimbel 3 st.   Trompet 8´       Trompet 8´
Basson 16´    Viola d. Gamba 8´         Cornet 4´
Schalmey 8´            Cornet 2´
Hautbois 8´            
            Bazuyn 32´ (ext.)



  • RW tremulant
  • BW tremulant - affecting also RW, HW and Pedal Cornet 2´.


  • HW-RW, BW-HW. More couplers available through Hauptwerk Master Couplers.

Virtual extensions:

  • Bazuyn 32´ is a virtual extension. It was added to the sample set as an hommage to Mr. Cornelius H. Edskes (1925-2015). The stop can be found on the simple jamb.
  • Praestant 32´ of the original instrument starts at low F.  Lower tones are made as a Resultant. A virtual extension of Praestant 32´ is available via a dedicated switch down to the bottom C.




Console view:

This is the general console view. It serves to define the keyboard MIDI inputs for all the divisions. The active part of this view are the manuals and the pedal. Specifying the MIDI inputs is done by right-clicking on the desired manual or pedal.



Mixer view:

The virtual listening position is adjusted here. Each perspective (direct, diffuse, distant and rear) has its own slider to adjust its volume.
The sliders in the lower row serve to adjust the volume of the noise components of the organ, i.e. the blower noise, the tracker noise, and the tremulant noise.
Pipe coupling and Pipe Detuning serve to adjust the amount of a "chorus effect". Higher slider position gives more overall mistuning to the organ pipes, possibly giving rich and tasteful organ sound. Lowest position of the slider offers the organ perfectly in tune instead (especially when combined with Hauptwerk Temperament charts). While Pipe Detuning controls the overall amount of tuning error of each pipe, Pipe coupling affects only the pitch error during the attack of the pipe speech.
The mixer settings can be stored, retrieved, reset. 3 different mixer settings can be stored/recalled any time. When the sample set is reloaded, the mixer setting 1 is used as default.
The switches in the top right corner allow for:
• extended compass of the keyboards and the pedal board,
• extended compass of the bottom tones of the Praestant 32' in the Pedal,
• switching between the real recorded tremulant and artificial Hauptwerk tremulant.
Below, the Fine Tuning Mixtures switch decides whether the perfectly tuned mixture/multirank samples will sound, or whether t he raw recorded (often beating) mixture/multirank samples will play back.
The blower switch should be always on. When off, the organ will stop sounding due to the lack of the wind.



Left+Right Jambs view:

The layout for dual touch screens. The design allows for portrait or landscape orientation, according to the orientation of the touch screens.
All the stops and other controls of the organ can be found here.
The drawstops can be engaged/disengaged by clicking/touching them. By right-clicking, MIDI switch can be attached to any of them.



Left + Right Jambs Vertical view:

The dual stop jambs offer vertical (portrait) orientation as an alternative.







Stops view:

Stops view with all the stops on a single screen is available in normal and wide landscape orientation.


Simple Jamb:

Simplified version of a single jamb to allow for more readable version of the stop names on small LCD touch screens.


Simple Jamb (Portrait)

An alternative simple jamb for portrait orientated screens.




The current version is 1.37 (for Hauptwerk 7 and higher versions) and it must be downloaded from within the user account and installed using the full installer, there is no differential upgrade from an older version. The major improvements compared to the previous versions is the compass extension to f3 and the pipe coupling/detuning feature. The mixtures and all the multi-rank stops are available in raw recorded (often beating) version, or in fine tuned option, user selectable via a mixer switch.

  1. St. Martini Sample set, Full Surround (8-chan.)

    8-channel surround variant (Direct, Diffuse, Distant, Rear). Encrypted, dongle protected. Minimum Hauptwerk version: 7. (Also works in all higher versions.).
    €837.89 Excl. Tax

    Detail & order

    Original price: (excl. tax)€1,529.00
    Bundle sale (45%):
    - €691.11
  2. St. Martini Sample set, Diffuse Variant

    Diffuse+rear channels. 4-channel surround variant. Encrypted, dongle protected. Minimum Hauptwerk version: 7. (Also works in all higher versions.)
    €739.00 Excl. Tax

    Detail & order

  3. St. Martini Sample set, Distant Variant

    Distant channels. 2-channel (stereo, "wet") variant. Encrypted, dongle protected. Minimum Hauptwerk version: 7. (Also works in all higher versions.).
    €640.00 Excl. Tax

    Detail & order

  4. St. Martini Semi-Dry Sample Set

    Semi-Dry, close-up recording. Plain wave format. Minimum Hauptwerk version: 4.2. (Also works in all higher versions.)
    Price: Excl. Tax: €599.00 Incl. Tax *: €724.79 Excl. Tax

    Detail & order