With regard to the DAC, it was hard to find one that was Dolby-compatible and had a volume control–which turned out to be a teeny-tiny button on each side to be pressed in for volume up or (on the other side) for volume down of the analog output. A joke, really, since I heard no change either way. I had been hoping for a volume dial with calibrations, but no such luck. The unit was purchased “used” from Amazon Warehouse, so I could try to return it or at least complain but not sure even a replacement would be any better since it was such a cheesy control.
As far as the adapter controls for ‘streaming’ and ‘surroundings’ I understand what you are saying; however, it is absolutely true that the ‘surroundings’ volume affects the ‘streaming’ volume, making it louder or softer with clicks either way, even though it’s only supposed to affect the microphone, not the electronic signal from the streamer. So that’s why I’d like to have my fitter try turning down the surroundings threshold by -3db. I don’t understand the audio physics of why this is happening, but it is happening nonetheless. I realize adjusting the surroundings setting down might make conversation in the room harder to hear, but it doesn’t seem to when I turn it down slightly by hand.
Finally, with regard to the MFI control on my iPhone, I have tried to adjust the settings for microphone and streamer and, guess what? The Philips app defaults the streamer volume to the ear-splitting 84db setting on the streamer. Adjusting the mic volume there would probably revert to the default for that, which at 64db, seems okay anyway. I suspect the mic/streamer (surroundings) volume on the Philips app is really some sort of hybrid, and that’s why the streaming volume is affected by changing it.