blumlein records XYtri © 2008-2014 by Andrew Levine @ blumlein records

Presented at the Workshop XYtri - From stereo to surround, and back! at the 25th Int. Audio Convention 2008 in Leipzig


For optimal sound I suggest using the VideoLAN VLC media player to audition the dts-encoded files.
XYtri is a practical and easy to use integrated solution born out of the need for an uncompromised traditional stereophonic recording when tracking projects also to be captured in surround.

The setup, consisting of three +-45°XY-configurations, results in three mono-compatible coincident stereophonic ranges (180° facing L, C and R) and two connecting stereophonic ranges (180° facing L-C and C-R) based on runtime-stereophony.


XYtri discretely maps to a 7.0 monitoring environment by extracting sum-and-difference information in the frontmost channels:
  • L = Central_XY_L - Central_XY_R
  • C = Central_XY_L + Central_XY_R
  • R = Central_XY_R - Central_XY_L
It can be folded down to 5.0, LCR (analogous to OCT-2), a combined sterephonic image as well as directed mono.
Recently I have used Ambisonic panners to translate the matrix to B-Format and Harpex-B to decode the image.

XYtri-mount prototype
you can mount it on a stand or fly it
XYtri-mount - extended arm
Easily extendable arms
XYtri-mount - centerpiece
The central piece
two arms can be folded together