How Do Hammond Organs Work?
Hammond organs have dual manuals, meaning that there are two keyboards which have pull-out drawbars that affect the sound. Learn about the rotating speakers of a Hammond organ with help from a professional musician and Hammond organist in this free video on how Hammond organs work.
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Hello, my name is Louis Pain. I'm a Portland, Oregon based Hammond Organist. I also, in addition to playing the instrument, I rent them out and I, and I teach. And today I'm here to explain or attempt to, how the Hammond Organ works. So for those of you who have never encountered one of these strange beast before, this is a Hammond B-3, the most famous model. They made them from 1970; 1954 to 1974 and first off you can see, unlike a piano or most of the keyboards, it's, it's dual manuals; it's two keyboards and there are all of these pull out draw bars along the top that affect the sound much like a, your EQ on your home stereo system duo. But first thing if you encounter one of these is you have to know how to turn it on. So that's done up here and first, you hit that switch, hold it for several seconds until it becomes stable sounding and then you add the second, while still holding the first and wait until again the stability is not changing and then you, then you can release the first switch. And how long you hold those two switches varies from organ to organ. This organs haven't made for; what is it, thirty five years now; so they vary a lot and sometimes you need to hold those switches a long time and listen and is it really not changing anymore, then you, hopefully you get some sound. So the draw bars; there's nine draw bars that you can set up to create a tone and then you could toggle between two sets of draw bars for each keyboard or manual. So for the B flat preset, these are the draw bars that create sounds. Or if you want to configure them whatever sound you want, the lower harmonics are at the left and the higher harmonics are at the right. That's even one tone that people sometimes use. And then there's also a unique sound that's unique to the B preset, that's these set of draw bars and that's the percussion over here; that's with percussion; that's without it and you can add that percussion with whatever draw bar setting you setup with these set of draw bars. Jimmy Smith was the person who came up with that sound and that's what his signature sound. So in terms of how the organ works, we have to talk about the Leslie switch which is right here and that changes the speed at which the rotating speakers and the Leslie speaker spin. The Leslie speaker is back behind me right now and if I play, that's the sound of the Leslie speaker with a speaker spinning at this low speed. And if I go to fast; so there a lot of dramatic things you can do that especially in combination with the volume pedal, although we didn't mention the volume pedal. The volume pedal is down there or the swell pedal as it's called and then finally we have the base pedals down here. But to really get into how the Hammond Organ works at this point I think we need to go around to the back of the organ and see what's under the hood. So now, we're looking under the hood at a Hammond model B-3. This is what the guts of the organ look like. Just a couple of basic components; this is the pre-amplifier, right here and behind that, running the entire length of the organ and covered by some green felt are the tone generators and that's sort of what is unique about a Hammond Organ. You know, even with all the keyboards that's been invented ever since, there's never been an instrument, electric keyboard instrument that sounded so live and natural and there's just something about it that hasn't been replicated. And the key is these tone generators. The Hammond originally was a clock company. They had an electric clock using a synchronous motor and there, according to the legend there was an accident in the factory one day and the sound was produced and Mr. Hammond bolted up and said, "That sounded like a flute; is there some way you could make an organ based on that sound?" So technicians got to work on it and this is what they came up with. So it's got the same original synchronous motor and it's turning this drive shaft that runs the length of those tone generators and attached to the drive shaft are all these wheels of different sizes, little metal wheels and they pass through electromagnetic fields and they pass a different sizes and different size; different numbers of notches; different speeds; all of that allows them to create different tones and then those tones are amplified through this pre-amplifier and then they're sent out front to the Leslie speakers. And here we are at the Leslie speaker; you can see here where the cable plugs in and this was not a part of the original Hammond organ design. The Leslie speakers were invented by a man name Don Leslie who brought the idea for his rotating speakered; organ speaker to Mr. Hammond, Laurens Hammond and he didn't like the idea at all and despite the fact it truly made the organ sound better. It's called the pipe voice of the Hammond Organ. It was; the idea was to sound something like the quality you get if sound from the pipes in a, in a pipe organ. It doesn't quite succeed at that but it does give a wonderful quality that sound, literally throws a sound around. And there's a twitter or horn speaker that points upward into this rotating horn and actually one of these horns is a dummy; it's just there for counterweight. The sound doesn't come through it. And then down below you have a woofer of 15-inch speaker pointing down into this rotating drum which is design to deflect, deflect the sound and throw it around and then on the organ, on the consul there's a switch called the Leslie switch and when I switch, when I flick the switch it changes the speed from the slow speed to a fast speed. So here it goes. And part of the reason it's a cool sound, it's very well-design; is that those, I'll go back to the slow speed, is that those two are spinning at different speed, in different direction. The horn is turning this way and the woofer is turning in this way and that helps create the unique sound of a Leslie speaker. And that is how a Hammond Organ and Leslie speaker work.