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Voicing facilities About voicing pipe organs When a real pipe organ is installed it is necessary to make detailed adjustments to the sound of each pipe, a process termed voicing. Primarily this is because the acoustic of the room in which it is installed will respond differently to different frequencies, and depending on the position from which the sound is produced (the location of the pipe) and the position of the listener, as well as for aesthetic reasons. For example, if a pipe with a fundamental frequency of 440 Hertz is placed at a point in the building that strongly amplifies that particular frequency (termed a node), then that pipe may sound much louder than its neighbours in the rank. The same applies to any of the frequencies (harmonics) present in the pipe sound, so the character of the sound can change very noticeably across the compass of a rank, due to the way that the room naturally accentuates and attenuates particular frequencies. The pipe organ voicer needs to adjust the speech of each pipe so that these effects are minimised from the point of view of the listener. The voicer also has the very important artistic role of adjusting the tonal qualities of the pipes so that all of the ranks sit well together, within the room acoustic, and produce the desired sound as a whole. Voicing in Hauptwerk Most houses and domestic listening environments have relatively 'dead' acoustics, which colour the sound only minimally. Likewise with headphones. Thus, when listening to an organ sample set that has been recorded 'wet' (including original acoustic) using Hauptwerk, often no adjustment to the sound of the sample set is necessary to be able to hear the instrument almost exactly as it sounds in its original environment. However, if Hauptwerk is used in a reverberant space, or if 'dry' samples are used, then the ranks will usually benefit very significantly from being re-voiced to some degree, just as with a real pipe organ. The Hauptwerk Advanced Edition has comprehensive per-pipe voicing facilities which allow different aspects of the sound of each pipe to be fine-tuned in real-time. These facilities are not available in the smaller Hauptwerk Basic Edition, so this section is only relevant for the Advanced Edition. Using the voicing facilities Hauptwerk stores voicing information separately for each organ. With a sample set loaded and active the voicing facilities are accessed by functions on the Organ settings menu:
Selecting the Reset all voicing restores all voicing stored for the organ to its default, and the sample set will then sound as it did when it was first installed, with any voicing changes you have made being wiped. If you select the option you will be prompted for confirmation. The main pipe voicing screen is accessed from the Pipe and rank voicing menu option:
Click on the above image to open a larger version in a separate window. Before opening the screen, engage the stop for the rank you wish to voice, so that you can hear the effects of adjustments to its voicing. Then open the screen from the menu and select the rank you wish to adjust at the top-left of the screen. Only ranks that are loaded into memory are available. Note that you can also engage and disengage stops whilst the voicing screen is open. Some sample sets use multiple layered samples for each pipe, although most do not. For multi-layer ranks, you can select the rank's layer that you wish to voice to the right of the rank selection. Next select the particular aspect of the rank's sound that you want to adjust using the Adjustment setting. For example, select the 'Overall: amplitude (dB)' setting. Note that if you have disabled any of Hauptwerk's audio engine features using either of the General settings | General options or Organ settings | General options screens then any adjustments that require those features will not appear in the list. The bank of slider controls in the middle of the screen will move to show the amplitude value stored for each pipe in the rank. Initially all sliders will be at their default positions in the centre of their travel since by default no voicing information will have been adjusted. The pipes are identified within the rank by a unique note number at the top, and the octave number and key name is also shown for clarity. Middle C is always note number 60. The lowest C on a rank of 61-note compass is number 36, and the highest is 96. Some ranks have larger or smaller compasses, and each slider is only enabled if a pipe exists in the rank with that note number. Press middle C and listen to its amplitude. Move the note 60 slider (middle C) up half way to the top of its travel and re-trigger the note. It should now sound about 12 decibels louder (about four times as loud). Note that some parameters require the note to be re-triggered to take effect, but most do not. You can use the up and down arrow buttons above and below the slider to fine-tune the position of the slider, or type a value directly (to one decimal place) in the text box below it. Drag the slider to the left of the octave marked QUICK downwards. You will see it move all sliders for the octave, incrementing their positions proportionally to how close they are to the slider. When you let go of the slider it will spring back to its centre position, but the individual pipe sliders will remain where they were are. The QUICK slider to the right of the octave behaves in the same way, with the right-hand end of the octave being affected most strongly. Together, these special sliders allow the response of a rank as a whole to be shaped very quickly. Often it is best to use these to shape the rank's response roughly at first, then fine-tune each pipe using its dedicated slider. To the far left of the screen is a slider labelled MSTR (short for master). This slider works in the same way as the QUICK sliders, but moves all of the note sliders equally for the whole rank, rather than just affecting one octave. This slider is a very convenient tool for initial adjustment of the basic sound of each rank, and the organ as a whole, prior to fine-tuning the parameters at the octave or individual pipe levels with the other sliders. Provided that the associated audio engine features are enabled, the following real-time adjustments are available for each pipe (and layer):
For all of the adjustments calibrated in decibels (dB) the slider specifies a value relative to the pipe's default value. For example, if you adjust the 'Tremulant sensitivity: brightness (decibels)' value to -6, then the depth of the brightness modulation that Hauptwerk applies to the pipe will be about half of the value specified by the sample set's creator (-6 dB equates approximately to a halving in absolute value). For percentage values, 100 percent represents the default value specified by the sample set's creator. The stereo balance only has an effect if the rank is routed to a stereo audio output (that is, if the channel format is stereo on General settings | Audio outputs). A stereo balance of -100 percent means that the left channel will be heard at twice its normal amplitude, and the right channel will not be heard at all. +100 percent is the opposite, and the default value of 0 percent means that the two stereo channels will be heard at the default amplitudes defined by the creator of the sample set you are using. Of course, for tremulant sensitivity adjustments to be audible, you must also have the relevant tremulant engaged, if any. Likewise, swell parameters have no effect if the rank is not enclosed in a swell box. The Lo/Hi EQ adjustments allow you to apply a simple low-pass or high-pass parametric EQ (filter) to the pipe, adjusting its balance between bass and treble. The transition frequency specifies the centre-point between the bass and treble bands. The transition width determines the steepness of the frequency response curve in the transition region between the bass and treble, and is specified as a percentage of the transition frequency. Generally it is best to avoid very low values for the transition width, since they will give a very steep frequency response and higher 'filter ripple' (an effect where the frequencies either side of the transition are boosted or attenuated excessively in a narrow band, compared to the rest of the frequency response). Equivalent parameters can be specified within the virtual organ by its creator of the organ, and the default values for the EQ parameters are taken from the virtual organ definition. Any adjustments to these EQ parameters override those specified by the organ's creator. Finally, note that some sample sets are intended only to be heard exactly as they were recorded and have licenses which explicitly disallow any voicing adjustments. For such sample sets the voicing menu functions are not enabled. |
