C# WASAPI. Play wav sounds simultaneously

I need simple C# app rendering few wav sounds simultaneously. The rendering needs to be done using WASAPI for low latency. The sounds will be preloaded. The signal to play one or another sound will come from 2 separate threads. Please do not bid if you havent got recent experience in playing wav files using C# and WASAPI. I dont want to use 3d party libraries (BASS, NAudio etc) but you can reuse their open source code as much as you like but in the end I want to have my own code independent from any 3d party dll. The code must work in 64 bit mode on W7.