Tag: DSP

Posted on

Two methods of reversible audio encryption in Max

This project demonstrates 2 reversible methods of encrypting audio

  • reciprocal (1/x)
  • frequency shifting

The reciprocal method is interesting because the reciprocal of a reciprocal is the original value. In other words you can reverse the process by doing it twice.

Frequency shifting allows you to ‘hide’ audio in the ultrasound range.

download

https://github.com/tkzic/max-projects

folder: audio-encryption

patches: voice-encryption2b.maxpat

Posted on

HISS impulse response tutorials

notes

From Pierre Alex Tremblay – 2 videos demonstrating how to create an IR using HISS tools

http://vimeo.com/tremblap/videos

Link to the paper which is not a photograph of the pages from the journal

http://quod.lib.umich.edu/cgi/p/pod/dod-idx/hisstools-impulse-response-toolbox-convolution-for.pdf?c=icmc;idno=bbp2372.2012.029

[update 1/2014]

Here’s the Max Patch from the video – from this C74 forum thread: http://cycling74.com/forums/topic/a-quick-tutorial-video-on-how-to-create-an-impulse-response/

the local file is: tkzic/max teaching examples/impulse-response-rodrigo-vid.maxpat

Ok, I must be living under a rock. Did not realize this stuff was in Live 9.

This tutorial explains how to use Live convolution reverb effect, as well as the IR measurement tool. The measurement tool lets you record impulse responses using a sine spectrum sweep. Essentially these are the Alex Harker Max tools made into M4L devices.

 http://www.macprovideo.com/hub/ableton-live/create-your-own-impulse-responses-in-ableton-live-9

Posted on

Laser audio

Today I built a laser pen solar panel audio transmitter thing – using these two sets of instructions – for the most part:

It works great, but I should have used a battery case instead of soldering the batteries together.

Built it into a Sparkfun box:

The next step is to experiment with filters – like an aquarium for example.