When i record for Librivox I normally use a condenser mic with a 16mm capsule, but when I DJ online I occasionally use a Logitech G533 gaming headset, but the pickup on the mic is atrocious for it being a Logitech. I did recently find an open source cure that does the trick. It is 2 programs that work together, the first being Equalizer APO available for free here; https://sourceforge.net/projects/equalizerapo/files/latest/download
And the second being PEACE Equalizer Interface, available here; https://sourceforge.net/projects/peace-equalizer-apo-extension/
You have to install Equalizer APO first and then PEACE, there is a great Help section included with PEACE. Then play with the settings and find what works with your rig.
Hopeful[y this helps people who may be having mic problems when getting started recording for Librivox. Just persevere, don't give up!