Live End Dead End

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Live End Dead End (abbreviated to LEDE ) describes a widely used equipment concept for control rooms in sound engineering , in which the front area of ​​the room around the main loudspeakers (sound source) is acoustically dampened in order to avoid reflections. In the rear area, the sound is scattered in order to increase the diffusivity . The listener (receiver) is usually still in the dead-end area, at most in the transition area. Often, but not always, the areas are divided in half.

origin

Typical listening situation in the 70s and 80s (HIFI position), similar to the original LEDE principle.

This empirical room concept was developed for two-channel stereo with loudspeaker reproduction. The advantages of this concept are therefore naturally not applicable to playback in multi-channel technology.

In contrast to the structure of today's control rooms and the use of the term, the control room developed in 1978 by Don and Carolyn Davis is clearly defined according to the LEDE concept. The reflections from the loudspeaker environment are attenuated in the half of the room there (“dead end”) and the diffusivity in the listening area (“live end”) is increased with suitable measures. The listener sits in the live end, which corresponded more to the typical listening situation of the HIFI user. This is also stated in the "Handbook for Sound Engineers" by Glen Ballou. Strictly speaking, everything else cannot be called LEDE.

function

Using the LEDE concept you want the respect reflections in the listening area (control room) the greatest possible start time gap ( initial time delay gap ITDG reach), for which the time between the arrival of the direct sound and the first strong reflection be as long must. Nevertheless, there should still be reflections in order to create an envelope impression. So it is inappropriate to absorb all reflections. In order to preserve them and still reduce their effect in terms of sound source location, the reflections are specifically scattered.

In small recording studios it is sometimes difficult to get this initial gap so large that it does not interfere with music playback. In terms of assessing the music mix, the initial time gap in the control room should be greater than that caused by the room when the music was recorded - regularly greater than around 20 ms.

Example of a modern control room with absorption in the front and diffusion in the back

Due to the large number of structural constraints, as well as the type and use of monitors and acoustic elements, there is no general recipe for setting up an optimal control room. There is still disagreement among the planners and acousticians about many details. How much the opinion about the "good" control room changes is shown by the article in the web links. The picture opposite is therefore only an example. But it shows the trend: The control rooms and monitor positions are now rather smaller than in the later user arrangement and the eavesdropper sits in the dead end.

In any case, it is important to understand that this concept is intended to improve the assessment of sound mixes and does not necessarily lead to a good sound quality room for enjoying music. Such a room concept is also only advantageous for sound recording in certain situations.

See also

literature

  • Glen M. Ballou, George L. Augspurger: Handbook for Sound Engineers , The New Audio Cyclopedia, Focal Press, April 2005, ISBN 0-240-80758-8

Web links

Individual evidence

  1. ^ Davis, D., Davis, C .: The LEDE concept for the control of acoustic and psychoacoustic parameters in recording control rooms. JAES Sept. 1980, 28/9, 585-595.
  2. ^ Philip Newell: Recording Studio Design . Taylor & Francis Ltd .; 2nd edition, 2008, ISBN 978-1138936072 , page 424.
  3. ↑ Keith Clark: A Conversation With SynAudCon Founders Don & Carolyn Davis . In: proaudioencyclopedia.com of May 31, 2015.