Leslie Speakers: Difference between revisions

[[Image:Leslie_Speakers_06.png|framed|none]]

The horn<nowiki>’</nowiki>s so-called coverage angle is taken from polar response charts such as these; it is the included angle between -6dB points from the horn<nowiki>’</nowiki>s on-axis level. Figure 4 and 5 show such coverage angles, compiled from a series of third-octave polar response curves. Note how the beamwidth gets smaller and smaller without the deflector. This means that if the deflectors are removed the sound will be much hotter on-axis, but much softer off-axis. Therefore, the AM portion of the Leslie Sound will be much more severe and "choppy", as many a rock and roller will tell you. Many Leslies played in clubs are faced backwards, with the top and bottom rear panels and deflectors removed, because the sound "cuts" better; an effect that translates as, "You can hear it better over the guitar player".

[[Image:Leslie_Speakers_01.png|framed|none]]

This beaming process will actually raise the on-axis sensitivity of any driver, as can be seen from the frequency-response curves of a University ID-40 driver (a respectable, but typical 3/4-inch throat PA unit) mounted on a Leslie horn with and without deflectors (Figures 6 and 7). It is interesting to note the extra sensitivity above 1.5 kHz available without the reflectors in place. (Note also that the low-end - 800 Hz to 1.5 kHz - response isn<nowiki>’</nowiki>t affected by removing the reflector, and that the response is ± 5 dB from 400 Hz to 10 kHz. This latter range could be made even flatter with a real-time analyzer and an third-octave equalizer in the studio.)