Helicon voice plates
The reed plate that is used for the basic bass in the Styrian harmonica is generally referred to as the helicon voice plate . But there are also chromatic accordions on the market that use these oversized reed plates in the bass section.
Helicon voice plates were named after their sonorous sound, which was reminiscent of the helicon wind bass instrument .
Design and manufacture
There are single and double reed plates. On the simple one, only the basic bass reeds are available. On the double there are additional reeds that sound an octave higher. The same applies to construction and function as for normal reed plates .
The production is slightly different. The reed plate frame is cast and reworked. Today, frame material is mostly duralumin . The steel reeds are screwed onto the frame with two screws. For very low tones, brass weights are usually soldered to the movable tongue end.
properties
pitch
The pitch of the basic bass reed is mostly in the range of Contra-G (G 1 to G, 48 Hz to 98 Hz), in some cases also lower down to Contra-C (C 1 , 32.7 Hz). However, the tone Contra-E (E 1 , 41.2 Hz) is already problematic because it has strong effects on the treble. The result is a volume modulation ( amplitude modulation ) of the same note played on the treble side.
volume
When viewed from the side, the helicon reedplate is wedge-shaped, with the greatest thickness at the free end of the reed. This thickness is related to the maximum achievable volume without any significant decrease in pitch.
Dimensions
- External frame dimensions: 13 mm × 50 mm × 95 mm
- Basic bass reed: slot length 70 mm
- Basic bass reed: slot width 8 mm
- Octave reed: slot length 53 mm
- Octave reed: slot width 7.5 mm
- simple helicon reed plate: width 33 mm
sound
In order for helicon tuning plates to function properly, the sound chamber ( sound chamber ) must be folded. The cross-section and volume of the sound chamber also contribute to the sound.
