Speaker breakup

Speaker breakup (or speaker distortion) and the interaction of the cabinet in the recording makes a huge difference in the tonality of the guitar/amo combination. The speaker breakup adds a sort of "other dimension" to the tone due to the excursion of the voice-coil. It adds a "bark" to the sound that you wouldn't normally hear. I would experiment with lower watt speakers (greenbacks esp.) if I were you.

-Greg