SeeD
Fractal Fanatic
it might be worth experimenting with the speaker resonance as yek suggested, but also using the room reverb in the cab block. it might give you a similar effect, but perhaps more natural sounding. i think we can assume that any cab resonances would already be captured in the IR, assuming the sweep was done at a decent enough volume to excite them....?
Yeah i know about the Room verb in the cab block. Have been using it some,and i works good,to add some room. But i feel this is doing something else,to the sound. Have you tried it with headphones ?