Cassotto

from Wikipedia, the free encyclopedia

The cassotto is an enlarged cavity on the treble side of an accordion .

technology

The Cassotto cavity acts as a passive filter, which lowers certain frequencies in the higher tone range (quieter) and amplifies others ( resonance ). The sound of an instrument with Cassotto therefore differs significantly from the sound of the instruments in normal versions.

It is common not to include all the choirs in the Cassotto room, only the low choirs 16 'or 8'. The remaining choirs are placed on the treble panel.

The Öllerer company builds a diatonic instrument with cassotto that has no register switches and is two-choir with two 8 '(M) choirs. The installation of a cassotto is more difficult with diatonic instruments because the arrangement of the reed blocks is very different. With chromatic instruments, a cassotto does not affect all tones to the same extent. The tones of the black keys are mostly on a sound post that is built closer to the upper edge of the filling. As a result, the Cassotto effect is lower for this sound post.

Cassotto registers are only offered by a few accordion makers. Beltuna , Pigini , Bugari and Öllerer are particularly well-known here . The cassotto hardly plays a role in traditional German accordion building. Cassotto registers can only be found sporadically in German accordions, for example at Hohner or Harmona ( Klingenthal ) in the models Cassotta, Supra & Supita II.

With the world champion Cassotta (374 + 414) a special construction, the so-called "Klingenthaler special cassotto" or also called "filling cassotto", comes into play. Here all the choirs are arranged parallel to one another, as in the normal accordion. The cassotto effect is created by a small "canopy" under the disc dome, which forms the cassotto room. The advantage of this construction is that the instrument can be tuned much easier (faster).

sound

The effect of a cassotto is differently pronounced for different instruments. The aural effect can therefore not be assessed in general. An individual assessment is required for each instrument. The Cassotto sound is often described as particularly warm and full. Due to the filter effect, the overtones are less pronounced.

There is also a certain interaction between the type of voice material used and the cassotto.

Frequencies between 500 Hz and 1000 Hz are generally amplified, but not uniformly. Some frequencies come out more than others, everything is more attenuated above 1000 Hz.

The outstanding sonic effect of the cassotto can also be described as follows:

  • the tonal influence occurs in sound formats that correspond to the spoken "o" or "a",
  • the muted areas, however, are in the umlauts area.

literature

  • Gotthard Richter: Acoustic Problems with Accordions and Harmonica, Part 1, Introduction to the General Basics. ISBN 3-925572-00-7
  • Gotthard Richter: Acoustic problems with accordions and harmonica, Part 2, investigations of special phenomena. ISBN 3-925572-01-5
  • Gotthard Richter: accordion. Handbook for musicians and instrument makers. 3rd edition 2003, ISBN 3-7959-0569-9