use X, Y and Z instead of XYZ

CALIBRATION.md

@@ -54,13 +54,13 @@ Now calculate the power envelope for all B format components, normalize everythi
 Extract the frequency response shapes from the B array. The second argument specifies whether to average all measurements (1) or only the on axis measurements (0). 
 
 ```octave
-[W XYZ] = sphear_fir_extract(B, 1, 1);
+[W X Y Z] = sphear_fir_extract(B, 1, 1);
 ```
 
-Redesign the FIR filter using the extracted W and XYZ shapes. The lower frequency range (below 5000Hz in this example) will directly use the A2B matrix coefficients to design the frequency response shape, the upper frequency range will use an interpolated polynomial over the average frequency response of each component as calculated above. 
+Redesign the FIR filter using the extracted W, X, Y and Z shapes. The lower frequency range (below 5000Hz in this example) will directly use the A2B matrix coefficients to design the frequency response shape, the upper frequency range will use an interpolated polynomial over the average frequency response of each component as calculated above. 
 
 ```octave
-FIR = sphear_fir_design(F, A2BF, 256, 12, 48000, 5000, W, XYZ);
+FIR = sphear_fir_design(F, A2BF, 256, 12, 48000, 5000, W, X, Y, Z);
 ```
 
 Filter all capsule inputs through the B format conversion, write a B-format four channel soundfile to disk: