making a rotating speaker cab

[sir_modulus]

anyone know how to make a leslie rotating speaker cab? I know it probably hard , but anyone know something at least close to it?

[R.G.]

One of the tricks that Leslie used was to not rotate the big, heavy speaker but to make it fire up into a styrofoam rotor that was scooped out on one side to direct the sound around. The rotor was spun by the rotary motor.

[sir_modulus]

wow thats a cool idea with a deflector plate. All this while i thought they were rotating a 12" speaker :shock: strange sight there. Anywhoo, anyone have any more plans for one, maybe like a diagram of it, or a webs. to show how to build it. Am making drawing now, my basic idea is to have an air tight enclosed speaker box with a small 6" car speaker (decent quality, will get some celestion or eminence speaker once I know this will work), and coming from the speaker will be a pipe which goes to the side of the box that is on top of the speaker box. This secondary box will have rotate so it aims the pipe around. I would also place an auxillary speaker(small) just to keep decent volume coming, and when the pipe aims at you....BOOOOOOMM!!!!!! 150W RMS of music in your face!!!!

any sugestions, comments, just post or PM me

LM 250+

[Peter Snowberg]

You might want to try getting an old record player that has a 78 setting and then mount your stationary speaker over the turntable. Put the deflector on the turntable and let it rip! The distance between them doesn't have to be too precise. 1cm of space between the rotor and the speaker is just fine. The "leakage" allows you to hear the sound a little better when the rotor isn't pointed in your direction.

I LOVE Leslies! Now that's true analog!

Best of luck,
-Peter

[petemoore]

I used old phonographs for stereo leslieing, but it's alot to carry and tote and wire...
 First one had two horns on the phonographs platter [what the record went on] two pieces of plywood and a couple struts later they were mounted < > one balanced as I could eye on top of the other.
 the phono plug went through where the centering pin came out, I used a C ration spoon with a string ball [wire attached] melted in it. The spring kept the contact pinned to the tip of the phono plug, for the other connection, I used points from a car, pinching the sleeve of the plug, mounted right to the plate.
 Worked just great, in or out of it's 5 sided box...but mostly high end...Olson horns.
 The next two were real homeym and really sounded like leslie, just made the scoop out of two square plywood sides, and a 45 degree elbow bend was put on 3/8 plywood, but I relieved the pull on the back by cutting part way through, in rows like lined paper...a common wood bending technique....fastened to the sides makes a very good scoop.
 How close the scoop is from the driver [speaker box] that sits atop it, the more sound is directed into the spinning scoop, and less sounds escapes through the 'seal' [has to be a gap there..] and causes cancellation of the effect and sound projection.
 I suppose the two way bend or 1/2 tube shape benefits somewhat, I found the wood made scoop to be quite effective indeed.
 The sound of a real leslie is too cool, if you liek to sit around and play, can't be beat...moving the darn thing is cumbersom.
 The scoop balance was obtained by very eyeing it as it's running to decide where counterweight neede to be added, alot of trial and error there...
 I made my speaker separate, just sitting on top, so it could be moved separately.
 About 3 foot out from the wall the natural leslie effect is reallly sweet, PDlow cost if you get a speaker and turntable...I opted for the quite old ones, they seemed to be pretty beefy. I'd get 'em out of old console stereos and such as that.
 I'd just give it a littel spin to help it get started, and save the belt maybe...it worked the whole Time I used it, I tried different speakers, of course a 'standby favorite' greenback was chosen.
 I didn't have a living room to keep it in, and it was wierd storing it, I finally ditched it...the speaker was needed to go with the other matching one for a 2X12'' cab... :cry:
 Nice thing about the scoop is you don't have to worry about your makeshift spinning connector skills/longevity...mine held up, but the horn model didn't see too much use after the novelty factor wore off.
 It takes an amp and speaker, other than that it's just the mechanics of it..gotta build a frame/box, real leslies have slots that let the sound out of the sides...I opted for 4'' wide planks with 1/2 inch spaces.
 Anyway I had two, one in each corner, all I can really tell you is: the Leslies I've known were all very nice.
 Real leslies have speed and brake knobs, some 3 speed models IIRC.
 Many belts, brake shoes, knobs, the controls on the keyboard...you'd need a control setup for all that...that's where it starts getting compllicated mechanically...the turntable takes care of this, but the speed may be limited by your ability to balance the scoop...I opted for 33 RPM max speed.
 I retrospect I might put a dowel rod across the open top end of the scoop for better counterbalance weight centering. and stability of the box in the elements.
 Smaller would probably do just as well or better, if you could find a good 8"" speaker or something..

[The Tone God]

During the short peroid of time Fender owned Leslie the Fender Vibratone used a rotating styrofoam drum with slot cut in the drum spinning in front of a 10" speaker. I thought that was way smarter then trying to spin something heavy like say oh...the speaker. *cough* revolver *cough*

Andrew

[Lonestarjohnny]

Sir Modulus,
I own 3 leslie cab's, 2 with 15's that go with my Hammond B-3, they sound Beautiful for guitar even though originally that was not the intension, I also have the newer S/S 12 in. version which is a lot lighter and not so big and bulky like the 15's, this is what I play guitar through and yes it does have a speed control pedal, this function is what give's it the neatest expression of all, as it's slowing down it's gotta be one of the greatest sound's I've ever heard, you can do a search on song's recorded with the Leslie sound and you'll be supprized at the no. and the people who recorded with these cabinet's.
I also own a 1X12 Vibratone Cab that I like also, it's smaller than the Leslie 1X12 cab, and for some reason, I'm guessing because of the Styrofoam baffling it speed's up and slow's down a little quicker than my Leslie.
SRV used the Vibratone live on many gig's here in Texas, he also recorded with one, it's great to hear one of these live being pushed by a Fender Super or Twin or any other amp by that matter,
there are good reading on any of this, just do a little surfin, You'll find even the Cabinet demension's,
JD

[sir_modulus]

thanks for helping out. The phonograph idea is good. I plan to either aproach it that way or use a stepper motor and get digital control of the thing(like have preset patterns(like pan only 90 deg.)) thank for all you help

LM 250 +

[AL]

http://www.theatreorgans.com/hammond/faq/mystery/mystery.html
http://theatreorgans.com/hammond/faq/

These may help a little.

AL

[Mark Hammer]

Somebody here down in Australia has a scanned article on their site from an old Aussie electronics mag demonstrating how to make a "rotor" using 3 pieces of hard-but-flexible board,  The directions are pretty thorough, and the remainder of the article has a great deal of info about Leslies in general IIRC.

Is it at hairbear's site?

I am beginning to think that the diameter of the rotor is important in achieving a useful sound.  At the modulation speeds routinely associated with "fast" and "slow" Leslie sounds, the circumference of the circle created during the spin is what provides the distance between wavefronts to permit cancellations in the band of interest.  If you make the distance between sound going in *this* direction and sound going in *that* direction to short, you won't get the tone associated with Leslies.

I have one of the little ones with an 8" speaker, and the styrofoam "cheesewheel" baffle (incidentally, I suspect that even though it is obviously light, the revving up time is more a function of the use of a belt-drive than of the actual mass of the baffle).  The speaker fires sideways/frontward, and the baffle redirects the sound along a vertical axis, rather than horizontal like the large 2-driver furniture console units.  The baffle is easily 18"in diameter.

I guess the message of this post is that there will likely be a certain minimum diameter of throw you cannot go below when it comes to the rotor.  That does not mean that the driver itself cannot be light and compact, or that the cabinet has to be large, or that the rotor has to be physically large (although all of this can obviously have something to do with amount of air moved and subsequent volume levels).

[David]

Sir Mod:

We had a BIG discussion about this back around the first of the year.  We were kicking around various mechanical and electronic approaches.  There might be some good gristle in there to chew on too.

[Hal]

i would think the hardest part is "turning" the wire, without it getting tangled.  You would need one of those things that i cant really describe - kind of a brush on a metal circle, to turn the electrical signal.  They have them in fencing reels :-D

otherwise...old washer moter from the side of the road?  Never tried it, but i doubt it would be _too_ hard.

[Mark Hammer]

You are describing what is generally called a "commutator".  The difficulties you outline are one big reason why many designs opt for a stationary speaker and moving baffle, rather than moving speaker.

As long as the sound source gets redirected, same deal.

[Primus]

I want to build one of these for my guitar, but I know they are voiced for organ (lots more bass output). I was thinking of maybe just making one of the rotating speakers instad of both the horn and the drum. Would anyone care to comment on whether or not this would be wise or if i would lose a lot of the mojo lacking either of these? Can I get by making only one and still sound great? Wich one should I make if I am just making one (horn or drum)?

[Dean Hazelwanter]

Here's another option. Find an old organ at a garage sale or thrift store that has the assembly. I still have the assembly that I 'harvested' out of an old Electrohome organ. For $20 (I think) it had the leslie assembly with an 8" Jensen, a 12" Jensen, ~20 x 12AX7s and a power amp (EL84 P-P). People at garage sales are sometimes only too happy to get rid of them!

Just make sure to look inside to confirm it has what you need!

I still have that assembly, and don't know what I'm going to do with it. Last year someone threw a Leslie 825 (?) cabinet in the bin beside work. The speaker (15") was gone but the mechanism was complete. I took out the essential components and would like to build a cabinet for it, this fall if time permits.

[Peter Snowberg]

:lol:

Arn't robots fun? There are probably hundreds of phpBB boards hit with that today.

I don't think we'll see a repeat post from this user.