An exciter (also called a harmonic exciter or aural exciter) is an
audio signal processing
Audio signal processing is a subfield of signal processing that is concerned with the electronic manipulation of audio signals. Audio signals are electronic representations of sound waves— longitudinal waves which travel through air, consist ...
technique used to enhance a signal by dynamic
equalization, phase manipulation,
harmonic synthesis of (usually) high frequency signals, and through the addition of subtle
harmonic distortion
In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signal ...
. Dynamic equalization involves variation of the equalizer characteristics in the time domain as a function of the input. Due to the varying nature,
noise
Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference aris ...
is reduced compared to static equalizers. Harmonic synthesis involves the creation of higher order harmonics from the
fundamental frequency
The fundamental frequency, often referred to simply as the ''fundamental'', is defined as the lowest frequency of a periodic waveform. In music, the fundamental is the musical pitch of a note that is perceived as the lowest partial present. I ...
signals present in the recording. As noise is usually more prevalent at higher frequencies, the harmonics are derived from a purer frequency band resulting in clearer highs. Exciters are also used to synthesize harmonics of low frequency signals to simulate deep bass in smaller speakers.
Originally made in valve (
tube
Tube or tubes may refer to:
* ''Tube'' (2003 film), a 2003 Korean film
* ''The Tube'' (TV series), a music related TV series by Channel 4 in the United Kingdom
* "Tubes" (Peter Dale), performer on the Soccer AM television show
* Tube (band), a ...
) based equipment, they are now implemented as part of a
digital signal processor, often trying to emulate analogue exciters. Exciters are mostly found as plug-ins for sound editing software and in sound enhancement processors.
Aphex aural exciter
The
Aphex aural exciter was one of the first exciter effects. The effect was developed in the mid-1970s by
Aphex Electronics. The aural exciter adds
phase shift
In physics and mathematics, the phase of a periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is denoted \phi(t) and expressed in such a scale that it ...
and musically related synthesized harmonics to audio signals. The first Aural Exciter units were available in the mid-1970s, exclusively on the rental basis of $30 per minute of finished recorded time. In the 1970s, certain recording artists, including
Anne Murray
Morna Anne Murray (born June 20, 1945) is a retired Canadian singer. Her albums, consisting primarily of pop, country, and adult contemporary music, have sold over 55 million copies worldwide during her over 40-year career.
Murray was the fir ...
,
Neil Diamond,
Jackson Browne,
The Four Seasons,
Olivia Newton-John
Dame Olivia Newton-John (26 September 1948 – 8 August 2022) was a British-Australian singer, actress and activist. She was a four-time Grammy Award winner whose music career included 15 top-ten singles, including 5 number-one singles on the ...
,
Linda Ronstadt
Linda Maria Ronstadt (born July 15, 1946) is a retired American singer who performed and recorded in diverse genres including rock, country, light opera, the Great American Songbook, and Latin. She has earned 11 Grammy Awards, three American ...
and
James Taylor
James Vernon Taylor (born March 12, 1948) is an American singer-songwriter and guitarist. A six-time Grammy Award winner, he was inducted into the Rock and Roll Hall of Fame in 2000. He is one of the best-selling music artists of all time, havi ...
stated in their
liner notes
Liner notes (also sleeve notes or album notes) are the writings found on the sleeves of LP record albums and in booklets that come inserted into the compact disc jewel case or the equivalent packaging for cassettes.
Origin
Liner notes are desc ...
"This album was recorded using the Aphex Aural Exciter."
Aphex started selling the professional units, and introduced two low-cost models: Type B and Type C. The Aural Exciter circuit is now licensed by a growing list of manufacturers, including
Yamaha Yamaha may refer to:
* Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below).
** Yamaha Music Foundation, an organization estab ...
, MacKenzie, Gentner,
E-mu Systems
E-mu Systems was a software synthesizer, audio interface, MIDI interface, and MIDI keyboard manufacturer. Founded in 1971 as a synthesizer maker, E-mu was a pioneer in samplers, sample-based drum machines and low-cost digital sampling mus ...
and
Bogen. The original Aphex Aural Exciter, first offered in 1975, came without the Big Bottom circuit, which was added in 1992. Later revisions of the Aphex Aural Exciter included the Model 104 Type C and Type C2 units. Aphex released in 2001
the Model 204 Aural Exciter and Optical Big Bottom, yet another refinement of the original unit. According to Aphex, the Model 204 updates the Aural Exciter and Big Bottom processor blocks with improved circuitry, including an optical gain-control element for the Big Bottom compressor.
Other brands
Functionally similar units from competing manufacturers are generically known either as "psychoacoustic processors", "psychoacoustic exciters", "harmonic exciters", or "enhancers". In the 1990s and 2000s, broadly comparable products became available from BBE, Joemeek, SPL and
Behringer
Behringer is an audio equipment company founded by the Swiss engineer Uli Behringer on 25 January 1989, in Willich, Germany. Behringer was the 14th largest manufacturer of music products in 2007. Behringer is a worldwide, multinational group ...
. Most are analogue signal processors, although a few digital units began to appear in the 2000s. The BBE Sonic Maximiser uses a similar process of frequency-dependent phase shifting, as do other brands to a varying extent.
Uses
*Making vocals sound more "breathy". This is why the original product was called an ''Aural'' Exciter.
*Enhancing dull recordings, especially analog reel-to-reel tape recordings that have lost their "sparkle" due to repeated
overdub
Overdubbing (also known as layering) is a technique used in audio recording in which audio tracks that have been pre-recorded are then played back and monitored, while simultaneously recording new, doubled, or augmented tracks onto one or more av ...
s.
*Restoring old recordings by simulating lost spectral content.
*As an audio enhancement for hardware and software media players.
*Exciters are sometimes sold in a "
stompbox" pedal format, in units designed for use with an electric guitar, electric bass, or electronic keyboards.
See also
*
Spectral band replication
Spectral band replication (SBR) is a technology to enhance audio or speech codecs, especially at low bit rates and is based on harmonic redundancy in the frequency domain.
It can be combined with any audio compression codec: the codec itself tra ...
References
External links
Enhancersarticle on
Sound on Sound
''Sound on Sound'' is an independently owned monthly music technology magazine published by SOS Publications Group, based in Cambridge, United Kingdom. The magazine includes product tests of electronic musical performance and recording devices, ...
Enhancers FAQon
Sound on Sound
''Sound on Sound'' is an independently owned monthly music technology magazine published by SOS Publications Group, based in Cambridge, United Kingdom. The magazine includes product tests of electronic musical performance and recording devices, ...
Aphex Vintage Aural Exciter Pluginby
Waves Audio
Waves Audio Ltd. is a developer and supplier of professional digital audio signal processing technologies and audio effects, used in recording, mixing, mastering, post production, broadcast, and live sound. The company's corporate headquarters an ...
{{DEFAULTSORT:Exciter (Effect)
Audio effects