Comment 30 for bug 1318360

I don't know if this will help anyone else arrive at a solution, but I observed alsamixer while switching back and forth between non-speaker phone mode and speaker phone mode in a phone call. While switching the mode I watched capture "devices" (not sure of the correct term) DEC4 and DEC6 change gain amounts as follows:

non-speaker phone mode
DEC4 at 68%, dB gain: 0.84
DEC6 at 80%, dB gain: 0.99

speaker phone mode
DEC4 at 70%, dB gain: 0.87
DEC6 at 68%, dB gain: 0.84

I'm learning about this on the fly because I'd like a solution, so I have no idea what to do next but maybe someone else does.