XySpace Combinator Patch

Tuesday, February 28th, 2006 | 11:36 am and filed in Reason, peff, Combinator.

XySpace is pseudo stereo spatialization combinator patch. It’s designed is to take a mono signal and position the sound around a virtual stereo room environment. A standard pan control positions the sound between the left and right channels, while a front-rear fader controls the distance away from the listener’s position.

The patch works by setting up a two different attenuation systems so that there are a total of four outputs from a mono input signal. Obviously, the four outputs correspond to front left, front right, rear left and rear right. The environment is setup as a large room, so reflections and reverb from the rear walls blend with the dry signal as the signal is positioned to the rear.

To simulate the effect of distance, a low pass filter is applied to the incoming signal to roll off high frequencies from sounds that are distance. This filter opens up as the sound is positioned closer to the front. A set of Malström comb filters are also applied to the front - rear attenuation to simulate the effect of doppler shift. As the sound moves toward the listener, the comb filter frequency decreases to induce the illusion of motion.

This patch is still somewhat in it’s infancy simply because it’s only been tested on headphones and the monitors of my workstation. The results could very easily vary depending on your set-up. The archive includes a couple of demo files that illustrate how the patch sounds and can be incorporated into various projects. The RPS XySpace example.rps has a couple of Matrix Pattern sequencers that modulate the position to constantly rotate sounds around the environment, while the XySpace Demo.rns file has controller changes recorded from a joystick control.

Many thanks to the guys on the messageboard who inspired the idea. I’m not sure how useful this is, but it’s certainly fun to play with.

Download XySpace.cmb

XySpace Parameters

Left - Right controls the stereo pan position of the incoming signal. The stereo separation is narrower for signals positioned towards the rear.

Front - Rear controls the source distance from the listener. The attenuation modulates several settings simultaneously, including a low pass filter as well as the comb-filter controls for the doppler effect.

Doppler trims the level of the comb-filter signals being combined with the dry signal. The doppler signal runs parallel with the dry signal, and the effect can be overwhelming depending on the source.

Room Decay adjusts the length of the decay time of the reverberation of the two RV-7000 reverbs used to define the expanse of the environment.

Hi Freq Shuffle Switch enables and disables the MClass Stereo Imager. Having this enabled is intended to create a proximity effect when the source signal is positioned towards the front.

Depth Filter Switch enables the the ECF-42 Low Pass Filter that rolls of high frequency signals on the front-rear signal.

Doppler Filters Switch enables the comb filtering to induce the doppler shift effect.

Rear Reflections Switch enables the second RV-7000 which is used to define the center rear wall of the environment.

9 Responses to “XySpace Combinator Patch”

  1. lagowski Says:

    Unfortunately my 1.25GHz PB can’t handle this material :-(

  2. Peff Says:

    Oy… Sorry about that! Is the Combi alone eating your CPU, or just the XySpace Example.rps?

  3. lagowski Says:

    The demo runs well. It’s the example file that screws it.

  4. moss garden Says:

    WOW!
    this works incredible!
    it adds so much to what i do anyway!
    thanks alot!

  5. Flandersh Says:

    Well, thank for a brief description of it! And thank you for taking the time to make it!

  6. djabacus Says:

    peff owns.
    awesome combi.

  7. Cornerman Says:

    Thanks Peff another cool Patch.

  8. dave manning Says:

    I wanted to know if you have a link for all of the combinators you have created.

  9. Peff Says:

    sure:

    http://www.peff.com/journal/combi-downloads/

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