Clues for a total newbie - Dub Siren/Bit Crusher.....

I'm a complete noob, just planning my first useful project and am hoping for some clues as to which of two directions is possible/best to pursue if anyone's able to help:

What I would like to do is build a "dub siren" based on this project:

but if possible also add a couple of pots that control sample rate and/or bitrate of the audio it produces.

I'm unsure if there's an easy way to do this with the Ardunio Due that forms the basis of the original siren, or whether I need to add another Arduino to process the sound coming from the Due....

for the latter idea, I guess this is a possibility, but I am hoping there's a more elegant/cheap way to do it with code?

Any advice gratefully received....

So you want to produce an audio file from the siren output? For that purpose you better use a PC-like computer with a sound card and storage device, to record the audio signal.

But you also can simply store the settings for such a signal, so that they can replace the pot inputs for a playback. This can be done one the Due, with storage in EEPROM or an added SD card.

Thanks - I think I am not explaining it very well!

I don't need to store the audio at all. I want to be able to control the bit rate and sample rate of the output of the dub siren project, but I only want to output real time audio.

I would prefer this to be Post the other control pots of the siren, but it may work pre the other controls too I guess....

but if possible also add a couple of pots that control sample rate and/or bitrate of the audio it produces.

The basic Arduino doesn't have a DAC so it only puts-out (8-bit) PWM which approximates analog and your "controls" are limited. If you add a WAV or MP3 shield you'll be playing files and you won't be able to change the sample rate or bit depth in real-time, you can only change the file.

I don't need to store the audio at all. I want to be able to control the bit rate and sample rate.

I assume you mean the bit depth.

Sample Rate = Number of samples per second. (CD audio is 44,100 samples per second or 44.1kHz.)
Bit depth = Number of bits per sample. (CD audio has 16-bits per sample.)
Bit rate = Number of bits per second, . (CD audio is 44,100 samples per second x 16 bits x 2 channels = 1411kbps. MP3 or other compressed formats can be much lower.)