hi,
i want to use pd to manipulate my guitar sound and tune it one ocatve deeper with software.

Due my poor english i haven't understood the manual section about fft completly and the exsamples not at all.

i just want to do a fft and the "reserve", so i thought about that:

[adc~]
 | |
[fft~]
 |
[osc~]
 |
[dac~]

to mainpulate the frequenze i thought i just hade to do some operatrion on the link between [fft~] and [osc~], but even the program shown does not work. any advice?
cheers.

You need many oscillators to resynthesise the signal from the FFT.

The easy way is to use the inverse FFT.

There are two kinds of [fft~] object. The one to use is [rfft~] which only gives the "real" part of the signal analysis. Combine that with [irfft~], the inverse real fast Fourier transform to get the signal back. Because it comes out with the amplitude of the blocksize you need to reduce the signal level a lot.

try

input
|
[rfft~]
| |
[irfft~]
|
[*~ 0.015]
|
output

Notice both outlets of [rfft~] are connected to both inlets of [irfft~]

Thanks for the advice, it works now the way it should.
but two questions:

-what is the [*~ 0.015] for?
-how can i now manipulate the frequency?
i just used a [*~ 2] bewteen [rfft~] and [rifft~], but nothing happens... why? i thought between these two elements the frequency submitted?