Ownhammer basically takes a test sound and runs it through a speaker (picked up by various mics) & sends that through a nice analog/tube mic preamp, then through an analog EQ (some with tubes for certain mics), then a program compares the two and injects the "extras" so you have an effect of just the speaker through a mic/pre/EQ to send your preamp or Eleven Rack through. They go a step further on some IRs and have multiple mics & room sounds, or a completely isolated dry sound or studio sound. It's good stuff. Reverbs are a whole new ball game, but you could make an impulse with an Ownhammer cabinet and your favorite reverb with Voxengo Deconvolver and a test tone in your DAW. Bounce the effected sound and load up the tone for the before and the new wav file so it can run a comparison. It gets very close for me, and helps with reamping stuff but doesn't always feel as good for tracking as just using the original Ownhammer IR once I change too much stuff.