I'm good at ideas, not electronics! Can someone help?

[Ansil]

ok that sounds cool RG   so we can't play with my idea. sniff sniff..   :wink:

[mikeb]

The crossover frequency is 800Hz, and the gentleness of the roll-off means some frequencies are reproduced by both the treble horn and bass speaker.

MikeB

[David]

OK, R.G., I'll give that a try!  Don't look for a fast build report, though.  It'll take at least a couple of months before I have anything at all.

Ansil:

I still like the electromechanical idea;   let's not let that get lost.  How about you tell me how or if you handled the variable-speed issue.  Also, are you spinning the speaker only, or the speaker and baffle together?

[R.G.]

ok that sounds cool RG so we can't play with my idea.

Of course we can play with your idea.

How's this: get some 4" PVC plumbing pipe, a big "T" fitting and two one-foot sections. Glue the one-footers into the cross of the T, and rig it so you spin the opening in the middle of the T over a 5" monitor speaker. If you like, stuff styrofoam into one of the one-foot ends to halve the effective rotation speed. Maybe glue styrofoam into a disk around the unit so it is not quite as likely to whack someone walking into it.

[Arno van der Heijden]

Instead, why don't we do this:

1. Crossover split the input signal, about 600hz like the real Leslie
2. Use a phaser (p90, p45, univibe, etc.) in vibrato mode for the frequency/Doppler shift and run the highs through this.
3. Use a tremolo circuit on the lows
4. Use just a hint of tremolo on the highs to fake the amplitude modulation in sync with the LFO for the highs
5. Mix all the stuff back together

Wouldn't you need some pitchshifting to happen as well? Like in a vibrato (with bbd's)?

[Ansil]

ok that sounds cool RG so we can't play with my idea.

Of course we can play with your idea.

How's this: get some 4" PVC plumbing pipe, a big "T" fitting and two one-foot sections. Glue the one-footers into the cross of the T, and rig it so you spin the opening in the middle of the T over a 5" monitor speaker. If you like, stuff styrofoam into one of the one-foot ends to halve the effective rotation speed. Maybe glue styrofoam into a disk around the unit so it is not quite as likely to whack someone walking into it.

lol  i was just kidding   :wink:

[David]

Instead, why don't we do this:

1. Crossover split the input signal, about 600hz like the real Leslie
2. Use a phaser (p90, p45, univibe, etc.) in vibrato mode for the frequency/Doppler shift and run the highs through this.
3. Use a tremolo circuit on the lows
4. Use just a hint of tremolo on the highs to fake the amplitude modulation in sync with the LFO for the highs
5. Mix all the stuff back together

What about this?
1.  As indicated
2, 3, 4.  A Zombie Chorus with Mark Hammer's "Badge" modification  for the highs and another for the lows (tweaked for bass response).  Drive them both from a single oscillator rigged to pulse at 60 for the slow speed or 340 for high speed.
5.  As indicated

[Arno van der Heijden]

I think it would be cooler to use a separate LFO for each section, so you can control the speed independently like in a real leslie.

[David]

Arn:

I don't recall seeing a Leslie that had independent speed control for the bass and treble rotor mechanisms.  I worked with a keyboard player that had the Leslie Combo Preamp unit.  As I recall, it had fast and slow speed controls.

[Arno van der Heijden]

David, to be honest, I don't know.
But if you want to include a ramping mechanism for switching between slow and fast speeds, you do want to control them independently because I believe the acceleration of each rotor isn't the same.

Btw, I was browsing through some patents on this subject. There's some pretty interesting stuff to be found for the more knowledgeable people (not me):

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=4,000,676.WKU.&OS=PN/4,000,676&RS=PN/4,000,

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=4,428,270.WKU.&OS=PN/4,428,270&RS=PN/4,428,270

[Nasse]

Since this popped up I could not resist to open my big mouth
Of course I could have posted this for Ansil´s thread about almost same things, but anyhow, I dont have a coin to throw...

I was testing that software rotary speaker emulator with fancy and plentiful controls of various parameters. I got some ideas, which are not tested or I am not sure about them, but ayhow...

I quess it may be useful to make crossover freq adjustable for guitar use. Original is fixed, but adjusting it in emulator made interesting chances in sound.  If guitar signal is not so interesting as tonewheel magig sine waves this may help, but just an opinion after short listening with some organ tracks

R.G suggested making it two in stereo setup. I think I heard in my soft simulator that the mix is probaply feed to a (slow?) phaser at the end of chain, maybe that simulates the sound motion in the room. That may be the cost-effective solution, but maybe not as good.

[Arno van der Heijden]

Nasse, what software is it that you're using?

[Nasse]

Oh, that was just something that come with Steinberg Cubase, a plug-in named Rotary. I think I have to fiddle with my files and folders, I cant make it work with my audio editor program, that has some meters like spectrum analyser and phase scope.

But I´m really novice with these

[Arno van der Heijden]

What about this?
1. As indicated
2, 3, 4. A Zombie Chorus with Mark Hammer's "Badge" modification for the highs and another for the lows (tweaked for bass response). Drive them both from a single oscillator rigged to pulse at 60 for the slow speed or 340 for high speed.
5. As indicated

Is there anybody who thought some more about this idea? I think it's kinda interesting. The H&K Rotosphere uses a similar kind of configuration.

Maybe a more simple version that uses a tremolo for the lows would work as wel. It might also be interesting to make a crossover network on a breadboard and use your typical chorus and/or tremolo pedal and a mixer to hear how it'll sound...

[Craig V]

What would happen if I used a full range guitar speaker (just a normal speaker without the Leslie crossover network) with a Leslie bottom?  Would it just be a tremolo sound or get that chorusey sound?