Surround sound

Surround sound is the term used for a spatial sound impression in sound recordings (English: ambience ). In a broader sense, theater performances can be included as well which give a surround sound experience.

History

Getting surround sound music has been produced by a number of orchestras and choirs, which were placed in the room at different locations (see Venetian polychorality ). Gabrieli was a master of this art, Johann Sebastian Bach, used this technique, for example, in his St. Matthew Passion.

Stereophony

The recording of music with two equivalent sound channels in perfect synchronization, developed in parallel for the electrical / electronic Tonaufzeichnungsverfahren and sound transmission with gramophone, radio and tape in approximately the same sound quality that in a left-right location of the - In the 1950s, the Stereofonie was developed allows playback through stereo speakers. Especially admission procedure in Laufzeitstereofonie and less in intensity stereophony allow localization of the sound source at depth, which is called Deep graduation.

Dummy head stereophony

A further development to improve the aural impression of this space is the dummy head stereophony or the headphone Stereophonic sound provided solely for headphone playback. In particular, the anatomy of the ears is in a artificial head, such as of plastic, simulated. In this high-quality microphones are used with omnidirectional polar pattern that capture the sound environment around the entire head, but especially with the ears rather than the ear canal. For concert recordings, even large orchestra, a single dummy head is used alone without additional more microphones. The playback of sound recordings can as I said only through headphones and not only conveys a left-right impression, but additionally a top-bottom and front-back impression. In the music world, the dummy head stereophony has not been enforced, there were many radio plays ( and still are ) produced, in which the possibilities of 3 -D space localization is targeted. There are problems in the direct front- localization.

Quadraphony

An extension of the Stereophonic sound was the quadraphonic sound in the four channels were recorded synchronously, with the additional two channels mainly contained the sound reflections and space signals of the receiving space. However, this method could not prevail because the additional information was too low. The matrixing degraded the sound. Especially in the broadcast technology no corresponding additional benefit was for the overhead of sender-side encoding and decoding receiver side, for the gained some experience with the introduction of FM stereophonic seen. So the marketing remained in the recorded music record limited, were developed for the pickup with frequency ranges from 20 Hz to 50 kHz ( CD -4).

Use in music

First protagonists of music for surround sound are Stockhausen (eg groups (1955 ) and Carree (1959 ) ), Edgar Varese ( " poeme electronique " ) and Pink Floyd (eg Ummagumma ).

Surround sound

Under surround sound, the movement and placement of sound sources in space by means of multiple loudspeakers is seen as a " surround sound ". In the Experimental Studio of the SWR a special matrix ( Halaphon ) was developed, which can control very precisely the movement and placement of sounds. With the digitization of sound processing tools developed many other institutes so-called spatialization of sounds. Software can be found, inter alia, in Ircam forum.

The licensed by Dolby method called Dolby Digital 5.1, 7.1 or Dolby Surround are moderately interesting effect for the cinema, but less suitable for reproduction of specific surround-sound music. Surround sound requires an equal treatment of all spatial directions, while the reproduction systems that have been developed for cinemas, such as Dolby Digital, SDDS, DTS, etc., always according to the optical center, ie in the direction of canvas, are aligned to the front. With Dolby Virtual Speaker, the company has developed a system for surround sound simulation from only one source (eg for headphones )

The company Serious Sound Labs is the licenser of Acoustic Design Modeling ( ADM) technology that reproduces a surround sound via multiple speakers and psychoacoustic matrix from a central source (eg, a central box instead of multiple satellite speakers )

Developed by Creative EAX is another method for surround sound specially for computer games.

The development of MP3, MP3 Surround support surround sound in a compressed format. The format is designed so that even a multi-channel piece of music can be played back on a conventional MP3 player. The software "MP3 SX " (MP3 Stereo eXtended ) is a converter which converts existing MP3 files to surround sound.