My audio commentary has a lot of background hiss. I suspect it is the onboard sound card gain method adding noise. So considering an upgrade to this sound card:
And, if required, this microphone.
The Zx has an excellent SNR of 116db. The microphone is a cardioid condenser so should highlight all the warm notes in my voice (or anyone else). I like the brushed aluminium one; ideally in a shock mount with a pop filter/screen.
Rando-noia 