I find that the minimum in-call volume on my HTC Desire is still far to loud on some calls.
Since I got the phone, I have flashed several different custom ROMs, radio updates, etc, and have had the issue throughout.
Do you know of any way (setting, hack, app, whatever) to reduce the minimum volume?
My device is rooted and I am currently running one of the CyanogenMod 7 (Gingerbread) nightly builds.
*Works with Wii-motes too.
I was reminded by a friend that the CyanogenMod ROM I am using includes 'DSPManager' which is essentially a graphic equaliser with profiles for Headset, Phone Speaker and Bluetooth Device.
By lowering all the levels for the Phone Speaker profile I have managed to reduce the minimum in call volume (hooray!).
For people using ROMs other than CM on a rooted device, I believe a combination of DSPManager APK and modified audio library can be flashed but people appear to have had mixed results.
I figured it out. You actually have to turn it up.....then turn it down. Doesn't make sense, but it is working.
I'm pretty sure Tasker can do this. I've seen references to people doing it, but I haven't found a specific profile/recipe for it. They have a 7-day trial you can get to fool around with it.