Exciter (device)
An exciter , also called aural exciter , (derived from English to excite "to stimulate", both in the sense of emotional stimulus and to cause vibrations ) is a musical effects device that artificially generates the high frequency component of a sound signal.
construction
The exciter consists of two elements connected in series: a high-pass filter and a distortion . This was originally designed as a quadrature multiplier, but a circuit with anti-parallel diodes is often used in simpler devices . In any case, the circuit generates new overtones above the cutoff frequency of the high-pass filter, which are based on the original signal as harmonics . The signal generated in this way is mixed back into the original signal with a low level component.
effect
The sound image changed by the exciter sounds more transparent than the original and can also be spatially better localized . Subjectively, the processing resembles a treble increase, although the level hardly increases measurably. Too much of the effect worsens the signal quality considerably, the sound impression becomes unnatural, distorted, annoying.
application
The exciter can be used for processing complete mixes as well as for individual signals. It is also suitable for “freshening up” inferior transmission paths. Here, an audible improvement is mainly achieved on simple playback devices (clock radios, portable radios, mini-systems), which make up the majority of the target market for the phono industry. Nowadays, an exciter is used for almost all mixes, individual signals rich in overtones, such as cymbals, are refined with it, and the device is particularly popular in advertising, as it promises to make the mix sound psychoacoustically louder at the same level.
history
The American Charles D. Lindridge built the first Exciter in 1955. The device made its market breakthrough in 1970 under the name Aural Exciter from Aphex. After the effects device could initially only be borrowed by the hour for high rental prices and its functionality was a well-kept secret, the most famous type C variant found its way into recording studios in the 1980s . In addition to the original from Aphex, there were soon alternatives (e.g. from BBE, Behringer , SPL ) and high-end versions ( e.g. from Höf ). The Exciter is now part of practically every high-end studio equipment and is also available as a plug-in for digital production environments.
Related devices
An enhancer works on a similar principle to an exciter, but instead of a high-pass filter, a number of band-pass filters are used. Many models do not generate new overtones, but analyze the existing ones, dynamically increase them and work with runtime effects to broaden the impulse . Depending on the frequency of the filter, the enhancer has different purposes and different sound properties. Examples of this are better speech intelligibility, a more spatial representation and a clearer stereo image.
literature
- Thomas Sandmann: Effects and Dynamics. 7th edition, PPV-Verlag, 2008, ISBN 978-3-932275-57-9
- R. Beckmann: Manual of PA technology, basic component practice. 2nd edition, Elektor-Verlag, Aachen 1990, ISBN 3-921608-66-X