I used to be an audio engineer and recording rock music is an odd thing. Think about it for a second. A rock guitar rig typically has 2X12" speakers and sometimes four or more. Not only does that amp play really loudly but it also pressurizes a room (more so with bass guitar). Then you have rock drummers which can produce peaks of 130 db. On the recording side you have transducers (microphones) that have, on the large side, 1" diaphragms which are attempting to capture all that sound. Trying to convince a rock guitarist to play on a much smaller amp is not often easy, but usually results in a better recorded sound. To control all of this sound you have to use some dynamic range compression and EQ. Getting all of these elements to balance, have fullness, and dynamics is really difficult, which is why really well recorded rock records always blow my mind.