I've been asked to create a simple version of a leslie rotating speaker for college, Ive never used pure data before so the mathematics of it is proving difficult. I have an auto panner and chorus working but I need a tremolo attached to run along side the auto panner at the same speed. Any advice on how to do this or addition help making it sound more like a leslie would be greatly appreciated. Please keep it as simple as possible I'm only a beginner, thanks.

Tremolo is just volume modulation. Multiply your signal with an LFO. For a Leslie sim, you want the tremolo to trail the panning and vibrato (you should be using vibrato, btw, not chorus) by 90 degrees so quadrature oscillators are what you need - not sure how that's done in Pd.

[phasor~]
|
[cos~]

makes a (co)sine wave oscillator

from the same phasor~,

[+~ 0.25]
|
[cos~]

makes a cosine oscillator 90 degrees offset to the first.

search this forum for vibrato. people have posted them here before.

A true leslie effect would be extremely difficult to simulate. At one point I analyzed the Dynacord CLS-222 schematic (it's a very well regarded analog rackmount unit). IIRC it uses a crossover to send the signal to two quadrature vibrato/tremolo circuits that run at different speeds. This does a reasonable job at simulating the separate horn and baffle parts of a leslie speaker.

yeah, but this is just a request for help with uni homework. we don't need to go that far.

how can you be a complete beginner?

it's november.

when did your course start?

were you off smoking bongs behind the bike racks until now?

henrebotha and myself have even given some tips on how to make things work. why not start with them?

I got the same to do for my university and I simply dont understand Pure data, im struggling to do my leslie speaker. Have you found some tips ?

Are you guys all in the same class or something?

maybe, kent university ? so struggling with Pure data, and because English isn't my first langage the help files doesn't help me at all.

Both henrebotha and mod have provided helpful tips and code on how to implement the leslie speaker, I think people might be more inclined to respond if they could see you've tried to understand what's been said before.

If it's because you don't understand Pure Data then I would suggest looking through some tutorials first - http://flossmanuals.net/puredata/

thanks for the website, it is really helpfull

can one of you guys explain why you're being asked to make a leslie speaker BEFORE they teach you anything about pure data?

Well, we have to go though worksheets first, 8 of them to learn about object (metro, mtof, bang,etc....). Before the leslie speaker we had to do simple synthesis and simple sampler.

This is the first assignment for the Pure data Module. The helpsite help me to understand a little bit. But I am still struggling to do the auto pan and the effect of a leslie speaker (the sound is lounder when the horn is positioned in front of the audience).

Our teacher also want us to have 2 different spead for the 2 speaker. (there is a crossover)

Thank you very much

PS : I think once you get your hand on pure data, it is logical.