The best replacement for wasapi is asio.

The best alternatives to wasapi are rated as following:
★★★★★  asio
★★★★★  directsound
★★★  kernel streaming
★★  asio4all
★★  mme
★  waveout
★  wdm
★  xaudio2
★  wasapi event style
★  directsound xbmc
  wdm/ks
  asio jriver
  wasapi event
  alsa

Your alternative for wasapi is not listed? Suggest!
Speaking about wasapi, one probably shouldn't forget about foobar.

Other search terms related to wasapi and their ratings are:
★★★★★ foobar
You have in mind a companion for wasapi and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of wasapi in all years. Click on graph for more.
wasapi
asio
directsound