First off, this is just a knowledge post. There is nothing you can do to help out unless you have ideas for hack drivers.

I recently upgraded my computer.

I went from a pre built compaq with the onboard sound chip. A Realtek AC'97 set. I had absolutely no problems with other people hearing me with this chipset, but the audio quality isn't the best.

I build my own new computer using a gigabit mobo whos' onboard chipset is another Realtek but this time an HD audio chipset (883 series). While the sound output did improve, the mic output SUCKS. There is no mic boost at all. So people can barely hear me although I have my settings cranked. Crank it much more and you'll get pops from pinging out.

So if people can't hear you, chances are it is because of lack of mic boost. Which saddly means probably half of the players out there due to how prolific realtek chipsets are.