Optional hrirCaller-supplied order-1 SH-HRIR. When omitted, the decoder resolves the
bundled Omnitone sh_hrir_order_1.wav (Apache-2.0) via
FoaDecoderHost.loadFoaHrir. Supply a 4-channel AudioBuffer (ACN
rows W,Y,Z,X) to override — e.g. in tests, or to ship a different
measured SH-HRIR. If you substitute a different file the WY/ZX row
grouping and the Y right-ear sign inversion must still match Omnitone's
convention (see FoaDecoder).
Construction-time configuration for a FoaDecoder.