Canz3D is an audio plug-in which processes sound to improve stereo imaging for listening with headphones. It performs a limited simulation of a room with two speakers. The dimensions of the room, it's acoustic properties and many other simulation parameters are adjustable. Canz3D is currently implemented as a VST plug-in for Mac OS. It should work with any VST plug-in compatible audio editor or other host under OS 8.6 and up, including OS X. There are separate versions for Classic, Carbon and Mach-O, as well as AltiVec and non-Altivec.
Stereo perception with headphones is generally limited to a sensation of sound being in one ear only or centered between them. Canz3D uses a combination of channel blending (crossfeed), frequency shaping and delays to simulate a 3D environment. Some high end headphone amplifiers incorporate similar effects, generally for hundreds to thousands of dollars. Originally, my intention was to build a home-brew crossfeed headphone amplifier. The plug-in was just supposed to be a way to test filters in software that I would implement in analog circuits. That plan didn't last very long as the complexity quickly outgrew any practical analog implementation and I decided to stick with a software solution.
How well Canz3D works depends a lot on the quality of your headphones and the sound being processed. With high fidelity audio recorded using stereo microphones, the results can be impressive. I find that with some classical recordings not only do I have better spatial perception, but I can more clearly distinguish instruments that seemed to blend together before. Most popular music is mixed from monaural sources by amplitude panning then compressed/limited to sound loud all the time. Canz3D will simulate what it would sound like on speakers in any case, but it can't restore fidelity or bring out a spatial image that isn't there. You may have to experiment with the simulation parameters to obtain the best results for different kinds of material.
The best way to find out how well it will work for you is to download the plug-ins and try it for yourself. I have also added some before and after sound samples to the site which I believe are a good demonstration but may not be representative of the material you want to use it with.
The unregistered plug-ins fade the output to silence after processing 3 minutes of continuous audio, which restarts every time the plugin is stopped/started. There is no demo expiration date. The limit only applies to the duration of audio which can be processed in a single continuous operation.
This version has an improved algorithm for computing echo magnitudes, constant power virtual panning, better compliance with the VST 2.2 SDK and one new preset program. There are also Mach-O versions and a Cocoa enabler application.