--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/aud-caramel/hds4.src	Sat Nov 06 04:28:43 2021 +0000
@@ -0,0 +1,22 @@
+# This audio mode config is for the FC-HDS4 headset plugged into the
+# main (EAR/MIC) audio jack on Caramel (iWOW DSK) or FC Caramel2
+# development boards.
+
+mic default {
+	gain 8		# tuned empirically for far end subjective perception
+	output-bias 1	# FC-HDS4 microphone needs 2.5V
+# Mic appears to have flat frequency response, thus no FIR needed
+}
+
+speaker ear {
+	gain 0		# left at default for now
+# We do have frequency response data, but no flattening FIR filter design
+# has been attempted yet
+}
+
+sidetone -17		# sounds reasonable
+
+# Let's try using Pirelli's non-loudspeaker (handheld/headset)
+# AEC config.
+
+aec-new 2 1 0x14 0xCCC 0x59AD 0x4000 0x32 0x1000 0x1000 0 4 0