Audio analyzing (hz & volume/dB)

I have an idea which I would love to test and make a proof-of-concept prototype.

I am prepared to spend some money, so do not hesitate to suggest a good solution, as opposed to a solution that might work.

Problem description:

I want to be able to generate a sinewave at a specified Hz. e[15,25000] Then, I'm going to amplify this signal and emit it through a speaker. Now I want to measure the volume/dB of this signal, at specific frequencies.

Basically I need to do this:

  • Generate sinewave at specified Hz (squarewaves are easy, how to convert them to sine?)
  • Sample and analyze audio data.
  • Filter data so that only data concerning target_Hz remains
  • Measure volume/dB or amplitude or some indication of volume.

  • Programmatically controllable EQ, preferably with an infinite number of 'bands' [hZ,gain,Q]

I suspect I might need to get some sort of DSP capable ┬ÁCU?

What do you hardware guys think?

Any feedback much appreciated! Thanks :)

Feel a bit stupid as I just found: http://www.dspguide.com

But any hints are still very very welcome!