This is the Hammond Company's best speaker cabinet that tonally compliments their B3 and C3 and other similar instruments. Unlike the Leslie Speaker, there are no rotary elements associated with the sound distribution in these speakers. They were made after Hammond developed their own true vibrato system for their instruments which made it unnecessary to have rotary elements in the speaker systems. In these speaker cabinets, the amplifiers are custom designed to match the frequency range of a typical Hammond console, and they also contain a very useful device that is known as a necklace reverb.

Practically all musical sounds are significantly improved if you listen to them in a large room or hall which can produce a certain amount of reverberation (sometimes referred to as "echo.") In a PR40 Hammond speaker cabinet, there is a device called a necklace reverb unit which will create a reverb effect similar to that which you get in a well-designed hall or music room. It does this by introducing a small amount of the musical signals from the console into three suitable transducers that then send a mechanical replica of these musical signals into one end of each of three specially wound, long and thin coil springs. Mechanical vibrations will actually echo or reverberate in coil springs in a similar manner to the way that sound waves echo and reverberate in larger rooms.

At the opposite ends of these three long, narrow springs, a second set of transducers converts the mechanical vibrations of the springs, which now represent the musical signals with reverb and echo added, back into an electrical signal again, after which this electrical signal is combined with the direct signal from the Hammond organ, and then the composite result is amplified and sent to several high quality speakers in the PR40 cabinet. Because these three reverb springs hang down in parabolic loops, they suggest the shape that a lady's necklace makes, which is how this device got its name.

The result of all of this is that the sound that you get from a PR40 speaker makes it seem that you are playing in a big, acoustically well-designed hall, which greatly enhances the overall musical result and is a significant sonic enhancement if you are playing a Hammond Organ in a small room, such as a typical room in a house or apartment.

At Main Street Music, we have original Hammond PR40 and also other similar Hammond speakers in excellent condition, available for immediate purchase while they last. We invite you to call us and visit our showroom to see, hear and play a Hammond through one of our excellent PR40 Speakers for yourself.

MAIN STREET MUSIC, LLC
719 Main Street
Waltham, MA 02451
(781) 893 6644, or find us on line at:

www.MainStreetMusicUSA.com