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Rotating Speakers and Simulators

2/2/1997 10:48 AM
Bryan Fishell
Rotating Speakers and Simulators
Is there anyone out there that can tell me a bit about the Leslie rotating speakers that have become more popular due to the retro-guitar phase? I really love the sound, I was wondering how available that these were. If they are not easily available, what would a good substitution be? I have already tried to do this by playing with the controls of a flanger. To me, the modulation waveform is too uneven, leaving the "fake leslie" sounding, well fake. Please help
2/4/1997 12:07 AM
Nobody is gonna post to this. There is alot ambiguity  
about rotating speaker simulaters, mostley because there  
aint one that works. The best you can do is a chorus set  
to its most square cutoff and highest speed run in your  
fx loop (if you have one). Otherwise you must run a  
tremolo signal paralell with a non tremmed signal. These  
are not the same, but a decent fake. If you run across a  
rotating speaker, be sure to run a fixed cabinet with it  
to get the full phase effect. Kinda tough yeah. But thats  
really how it is.  
2/4/1997 9:39 AM
Mark Hammer

It's been almost 17 years since I sold my Leslie, and I still miss it.  
They vary considerably in their design. The one I had was simply an 8"  
speaker with a styrofoam baffle that got turned by a two speed motor. I  
ran it from an external speaker jack I installed on my Princeton. This was,  
of course, the smallest model one could get. Larger ones, intended to be  
heard in spaces larger than living room, use multi speaker systems, and  
have built-in bi-amplification. The mid's and high's go out through a  
rotating horn, and the lows go out through a stationary woofer.  
There are actually many ways to mechanically reproduce the Leslie sound.  
Bear in mind that they all serve to produce Doppler cancellations by having  
a moving sound source. How the sound source moves is your own business,  
as long as it moves. AS noted, my old mini-Leslie had a single fixed speaker  
with a styrofoam "baffle" over it. Uh, try to imagine a big cheese wheel,  
about 16-18" in diameter, about 8" high, with an 8" diameter dugout in the  
middle, and an additional horn-shaped dugout extending from the edge of middle  
section to the outside of the "cheese-wheel". As the whole stryofoam assembly  
spun around, the sound would be directed out the "horn" moulded into the form.  
So, even though the speaker was stationary, the sound moved around. The advantage here is that one doesn't need an electrical commutator to maintain  
electrical connections to the speaker as it spins around, since the speaker  
isn't spinning in this case.  
A second approach, tried by Roland in the late 70's and early 80's, was to  
use four stationary speakers, mounted on each side of a cabinet, each  
connected to its own amplifier, and electronically pan around using VCA's  
ahead of the amps. So, speaker A would be at 20%, speaker B at 40%, speaker  
C at 60%, etc. As each channel got louder and softer in sequence, the sound  
would appear to move around, and some cancellation would occur. I think  
there may have also been some electronic doctoring/tweaking of the sound  
(Boss Chorus with rotating effect?). It was discontinued shortly after its  
introduction, although I'm not sure why.  
The most desirable Leslie-type sounds are produced through a true Leslie  
speaker, rather than electronically. Why? IMHO, this is result of the  
joint occurrance of several factors.  
1) The harmonically richer the sound signal, the more apparent the effect.  
Tacking on the Doppler cancellations at the tail end of the signal chain  
will result in the signal being at its harmonically richest, due to the  
cumulative distortion across the entire signal chain. Stick your flanger  
ahead of your overdrive, and after your overdrive, and you'll see what I  
2) Leslie's have tube amplifiers in them, so the distortion at the tail end  
of the signal chain is a nicer distortion to most ears. If you've  
followed any of the tube/trans debate over the last 10 years, you'll know  
that a case can be made for the distortion stemming from the tubes, the  
output transformers, the cascaded pre-amps, and so on. They're probably  
all relevent.  
3) The more continuous the sound movement is, the nicer the sound. Mechanical  
sound movement is more continuous than electronic sound movement.  
4) The physical omnipresence of sound that occurs when using a real spinning  
speaker, with the sound whipping around everywhere, is a more visceral,  
and inspiring, experience than having the same cancellations come from  
a single sound source (i.e., electronic simulator coming out of 2-12's).  
Those who want to tinker with rotating speakers can consider the following:  
1) The goal seems to be to get a continuous motion. If you can't have a  
moving speaker (i.e., you're using electronic panning), then try to have  
as many speakers in a circle as possible (e.g., a hexagonal cab with 6  
speakers facing out in a circle).  
2) Electronic commutators are awkward and expensive, so simply redirect the  
sound a la "cheese wheel".  
3) Try to feed as gritty a sound as possible into the speaker. Much like  
voice boxes (you know, the Joe Walsh/Peter Frampton gadget), Leslie's  
love pre-distorted sound.  
One last note. On one of the last occasions when I used my Leslie, I had it off to one side of me, and a guitar amp with a slow tremolo setting on my other  
side. 17 years later, and I'm STILL dizzy from it. Wow! What a sound.  
Bear in mind that you do not need to have either a stationary-unaffected  
speaker, nor concurrent tremolo, to achieve and appreciate the classic Leslie  
sound. I had one crummy 8" speaker pumped with 6 watts of the finest 6V6GT  
sound, and the tone was classic Leslie and awe-inspiring.  
Talk amongst yourselves. I'm getting a little farklempt!
6/27/1997 3:53 PM
Ken Lewellen

I an old "cheese wheel" model 16 Leslie although it was intended for a 10inch speaker it has a 12 inch mounted in it. Also I use an additional "rotor" on top of the cabinet with an 8inch speaker mounted in it. This top one only spins when the model 16 is in tremolo mode.  
Sounds really cool with guitar or organ. One interesting aspect I found is, since the room that  
my equipment is in is rather small, when the upper rotor is spinning, any instrument played in the room has a tremolo effect. It doesn't have to be connected to the leslie. Cool.  
Ken Lewellen
2/24/1997 8:59 PM
Chris Russo

I think most knowledgeable folks will tell you that all of the "fake" leslie's sound fake.  
I agree. There are some cool sounding simulators though. Univibe being my personal favorite.  
Guitar Player Magazine (? issue 2 or 3 months ago ) reviewed a Digitech RPM1 and thought it sounded pretty cool.  
I've seen 1 or 2 small rack mounted and free standing leslie style devices, unfortunately I can't recall  
the brand names :::::blush:::: Possibly someone else here will recall. One of which I saw at Guitar Center  
in Fountain Valley,CA in their keyboard room. The best sounding non-leslie , leslie I ever heard! and  
fairly small too ! Get out there and look around you may find one. I'll Email you if I can recall the  
manufacturers name.  
3/27/1997 8:06 AM
Cliff Ducharme

Trying to simulate all of the subtle phase cancellations, doppler shift and general acoustic qualities of a Leslie speaker (my favorite was the model 122 with a 40W tube amp, 15" Jensen and horn driver, all in a wood cabinet) is nearly impossible. Even recordings don't come close to the live sound, especially a Hammond B3 with a pair (!) of them separated by 20-30 feet. The best electronic approach is a digital flanger that that will allow tweaks of the sweep waveform and mix of original and delayed signals. Otherwise, plan to haul around a 100 LB+ box with motors, rotating baffles and horns. But there's no question about how wonderful the sound is.
8/29/1997 6:13 PM
bill g.

I've had great luck with the Dunlop Rotovibe pedal. I've also heard the Univibe and it sounds cool too. The best thing is they weigh a LOT less than a Leslie:-)
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