Reverb plate (acoustics)
A reverberation plate is an electroacoustic system for generating artificial reverberation .
A Hall plate consists of a freely suspended steel plate that is excited to vibrate by an electromechanical transducer. The vibrations spread as a wave on the plate and are reflected several times at the edges. With the help of one or more microphones , the vibrations are converted back into electrical signals.
The reverb plate was used in early recording studio technology. A rather unnatural impression of a room simulation is created not only by the high-altitude reverberation, but also by the lack of early reflections. Further disadvantages of the reverb plate are its large dimensions (at least 1 × 2 meters because of the high speed of sound in the material), its high weight, its sensitivity to vibrations and sound, and its high price.
To vary the reverberation effect, the delay time and the decay time of the reverberation can be changed. On the one hand, the location of the microphone for extracting the reverberation on the record can be changed - the closer the microphone is to the transducer, the shorter the delay time. On the other hand, the ability of the plate to vibrate can be changed by mechanical dampers . This will shorten the cooldown time.
A further development of the Hall plate works with a thin gold foil; the structural design does not differ from that of the steel plate, but is smaller and lighter. This was the first time the mobile use of an artificial hall with appropriate quality in z. B. OB van possible.
Other electromechanical systems for generating artificial reverberation are the tape reverb device and the so-called spring reverb (" reverb spiral"), a mechanically excited coil spring that is much cheaper, smaller and lighter, but sounds much worse.
Due to the digital signal processing , these devices are historic.
literature
- Thomas Görne: Sound engineering. 1st edition, Carl Hanser Verlag, Leipzig, 2006, ISBN 3-446-40198-9