Try a different mic position. I have visited Fluff's website several times as he reviews many products and he suggested using the mic off axis to the speaker. Positioned such that the mic is pointed towards the intersection of the dust cap and cone but at an angle and not straight into the speaker. Also try compression with unity gain if you have that option. Generally during mix down I will apply EQ to alter the tone characteristic of that channel used to record the guitar. However, since I do not have a 2x12 cab used with my Roadster, the 412 is not as boomy or bass dominated. I would not port the cab as that will increase the mid dominance of the V30 (reason why I opted for Celestion G12H-75 creamback for the RA100 Combo) as the ported cab resulted in mid mudd that was difficult to dial out (it did sound great with a mix of the V30 and creamback but I prefer the creamback with that amp).
Also try moving the mic out from the amp grill. V30's will create a beaming effect due to the fabric dust cap and relative small size. Perhaps mic at center with offset pointing to the midpoint of the cone. When recording, I generally use two mic's with different response characteristics SM57 and RE320 (single channel for each or even add a stereo channel for both). Getting a good mic position is more of a learned art than I had thought.
