Aphex Systems - Aural Exciter

Aural Exciter

The Aural Exciter is said to enhance clarity and intelligibility by adding phase shift and musically related synthesized harmonics to audio signals. The Big Bottom circuit combines a low-pass filter and dynamics processor to compress and delay incoming low-frequency information. The process is reverse amplitude dependent, meaning that more is applied as the input level drops and less as the signal gets hotter. Together the dynamics processor and time delay create sustained bass frequencies that are perceived as being louder yet do not noticeably increase peak output.

The first Aural Exciter units were available exclusively on the rental basis of $30 per minute of finished recorded time. The unit became so popular, especially with the Los Angeles music and recording studio scene, that Aphex had to move to Hollywood. In the 1970s, certain recording artists, including Nina Simone, Jackson Browne, Linda Ronstadt, The Manhattan Transfer, Donna Summer, and James Taylor stated in their liner notes, "This album was recorded using the Aphex Aural Exciter."

Recognizing that there was a much bigger market than just the rental business, 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, MacKenzie, Gentner, Emu 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 has now released 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.

Functionally similar units from competing manufacturers are generically known either as 'psychoacoustic processors' or more commonly just as 'enhancers'. Broadly comparable products are now available from BBE, Joemeek, SPL, and Behringer, Aphex is considered the "gold standard" and benchmark of audio signal processors. While most are analogue signal processors, Aphex has created a variety of digital processors and software versions of its technologies for use in products and in licensing.