Leslie speaker

A Leslie speaker ( Leslie speaker, also known as rotary speaker, Leslie sound cabinet, Leslie box or shortly Leslie known) is an effect unit for electro- acoustic sound change in musical audio signals, beats are generated in the use of a triggered by rotational Doppler effect.

It is named after its inventor, Donald Leslie, the Leslie ( 1911-2004 ).

History

Don Leslie offered his invention in 1940 initially Laurens Hammond for his Hammond organ to which it has categorically rejected it. Leslie then founded the company Electro Music in Pasadena and built for his organs systems. It was not until 1980 it came to forming the company Hammond Suzuki / USA through the acquisition of the company CBS to the Electro Music now belonged to the direct collaboration with Leslie.

Regardless of these problems in marketing both systems were resourceful musicians and technicians combined with each other since the 1960s, and since then shape the sound of the Hammond organ with decisive.

The original name of the Leslie speaker was " Orgasm ", but he was also called " Brittain Speakers": 1941 Leslie began a partnership with a Lou Brittain, this was disbanded after the war. Leslies were also known as " Hollywood Speakers" ( they were built in California near Hollywood) and " Crawford Speakers " ( organist Jesse Crawford was the first Leslie - seller in the New York area) known. 1946, the name was again changed to " Leslie Vibratone " to end the confusion. Most people called it simply " Leslie", and in 1949 had the name Leslie fall " Orgasm ".

Principle

The outstanding feature of a Leslie rotating the Schallabstrahler sitting in front of the speakers. Sense of rotation is to produce a vibrato, that is, modulation of the pitch by using the Doppler effect, and the resulting beat frequency.

When the rotating speaker from the listener, so that the sound is deeper. At the same time he approaches the opposite wall, which is therefore sonicated with a higher tone she reflected also in the direction of the listener. This happens at any point in all directions of the space. The listener learns thus a very complex sound that goes far beyond a simple pitch vibrato and the Hammondsound enriched.

In connection with the Hammond organ Leslie met the sound roughly the same function as a " Tremulant in the main wind tunnel " in a pipe organ.

Technology

The classic Leslie is constructed as a two-way system, with separate speakers for the tweeter and the bass range. Simple models had fixed medium / treble and the bass drum was rotated only. Meanwhile, there is also a one-way system.

The treble is reproduced with the better models of a horn is a double horn. In this case, however, the sound is fed through only one of the two horns, and the other horn serves as a counterweight. The treble rotors accelerates and decelerates faster than the bass rotor, since the bass rotor has a larger moment of inertia due to its higher mass. The rotation is controlled in two stages via a switch on the organ or through a preamp pedal (Combo Preamp). During the slow turning of the rotors ( " chorale " ) creates a chorus Similar effect. During fast turning ( " tremolo " ) produces an effect similar to a tremolo. On some models, the rotation can be turned off. Acoustically particularly appealing are the effects occurring during acceleration and deceleration. The motors for fast and slow rotation are composed in older Leslie models of two individual mechanically coupled motors, while newer models usually only a single motor is used, which is provided with a corresponding electronic control.

Particularly powerful sound called Rotosonic drums that work in place of the Schallumlenktrommel as a bass rotor. Actually These drums sits a 6x9 "speakers in a drum and the sound signal is passed through a specially developed mercury - contact. Modulation effect in the bass range is more intense in these models than in the original Leslie. These drums are much heavier than the idlers and speed up or slow down correspondingly slower. Leslies with Rotosonic bass rotors have an extra bass speaker which transmits frequencies that are too deep for the 6x9 "speakers in the drum.

Other components of the Leslie are the built-in amplifier, and on some models a reverb unit that is constructed with a spring reverb. In addition, a crossover is integrated ( passive or active), which filters out the different speakers the appropriate frequency ranges. Some Leslie models additionally have fixed speakers that the playback of non - organ sounds (eg, string ensemble, piano, bass ) or a Hall signal serve.

At a systemic disadvantage of Leslie already has the additional designation "cabinet" out: The Leslie unit is large and heavy and therefore harder to transport. The Leslie Cabinet continues to serve only the sound production: there are fed audio signals after processing not, as in other effects, again as an electrical signal, because it itself does not have microphones. The microphone decrease of Leslie thus allows more influence on the sound and plays a special role in music production. It must be used with at least two microphones to record the spatiality of the Leslie sound. The arrangement of the microphones and the reproduction space are critical sizes. Especially at high rotation speed can occur mechanical and propeller-like noises

Despite the reluctance of the organ builder Laurens Hammond against the " Leslie " effect it gave the products he organ models T and N with built-in rotating speakers that were also called Leslie. These were housed in the base of the organ and slightly smaller than the typical cabinet speakers.

A tail pulley (Leslie Model 760)

A Rotosonic drum (Leslie Model 722)

Replicas

Various manufacturers have tried to replicate the sound of a Leslie electronically. However, since the typical "floating, whirring " sound is a combination of vibrato, tremolo, and phase shift, which moreover runs differently for high and low clay contents, it has been possible only with the availability of faster and cheaper computing power digitally, the effect in the computer to simulate. In live performances, an original Leslie cabinet for a trained ear, however, is easily distinguished from the electronic simulation. Under most musicians use a simulated Leslie is frowned upon. A quote from the keyboardist Bobby Sparks for this is " There's nothing like the real thing, man! " ( Nothing is like the real thing, man! ) However, giving price, weight and bulkiness of a real Leslie cabinet usually the rash, but on a digital simulation recourse. An exception here is the manufacturer Reußenzehn, which reconstructs a rotary cabinet with real rotary speaker tube-based.

Clips

The following examples were taken with a XB -1, a portable all-digital organ from Hammond home.

The first example makes audible using a simple chord, such as the Leslie only running at low speed (you have to listen carefully, so that you can hear the slow rotations of the speakers). Then, Leslie is switched to high speed, you can hear well that the treble rotors much earlier than the terminal velocity reached the bass rotor. Then switch back to low speed, the treble rotors turn much faster in speed drops as the bass rotor.

Hammond organ, Leslie Effect Slow -Fast - Slow:

The second example consists of a short chord progression of said three points, Leslie is accelerated.

Hammond organ, different sequences with Leslie effects:

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