Gedackt

Gedackt (also Covered ) is the name of registers of the organ, whose pipes are closed at the top. In a narrower sense are understood Gedackt only pipes that have the same extent over the entire length, eg, cylindrical metal pipes., Stopped whistling with him to the gedackten end tapered scope, eg conical metal pipes are called Spitzgedackt and behave physically different.

Characteristic is the design with flue pipes, the upper end closed ( Gedackt / covered ) is. In ( round ) Metal pipes are, however, used a lid on ( square ) wooden pipes a bung. The closure with the result that the sound produced by such a pipe is an octave lower than the pipe length can be expected. This is because the standing wave in the pipe body by reflection at the tube end there was not a speed maximum ( antinode ), but forced to be a pressure maximum ( vibration nodes of the sound velocity ) has. Inside the pipe is then instead of the half, as in the open pipe, a quarter of the oscillation. The wavelength of the fundamental resonance is twice as large., Stopped pipes can therefore be regarded as a closed one-sided.

, Stopped in octave are ' (rare in the pedal, in giant organs also in the manual ), 16' in the footages 32 built, 8 ' and 4'. Gedackt 2 ' over the entire manual range is rare, as it is in high position are difficult to produce. In some giant organs is also a gedacktes 64' - register in the pedal. However, a fully developed, so reaching to the Subsubkontra -C, 64' - Gedacktregister is not yet known. The Quinten 211/3 ' ( in the pedal, rarely and only in large organs ), 102 /3' ( in the pedal ) and 51 /3 ' are also almost always run as, stopped. Gedackt 8 ' is very common nowadays and in most small organs the only labial 8' register.

, Stopped registers are considerably quieter than open registers, sound slightly hollow and are also darker in its tone. In overtones only even harmonics are present, corresponding to the odd-numbered partials. The other harmonics, including the octaves are missing. A narrow bore and Gedackt can be built so that the 3rd partial, the twelfth, called in organ building as Quint, emerges, what is the origin of the name Quintatön or Quintadena for such registers. In a still narrower bore enters the fifth partial tone, which is two octaves and a pure major third above the root, and is denoted in organ building as a third, forth. This register is called Tiercina and is rare.

Gedacktregister be constructed with a round cross section and made ​​of metal with a square cross-section of wood. Every now and then even the deepest pipes of an open register (eg reed pipe, hollow flute, principal) are executed Gedackt to save space, weight, material, or cost.

Spitzgedackte are sound between open and gedackten registers. Unlike gedackten pipe over the entire length to the same extent at all Spitzgedackten overtones contained in the spectrum. The length of Spitzgedackten depends on the change in cross section and is located between the cylindrically gedackten and open pipes.

Other instruments

Also, some species have a flute, stopped construction. While the tube end is open in most flutes such as the recorder and flute, such as the pan flute has closed ends. The tonal difference between an open and a stopped flute can be good on a recorder head illustrate by one blow on it open and once the bubbles covering the bottom opening with the palm.