OK. Here goes:
The root of this question is the concept of frequency dependant dynamic swing vs. (perceived) 'steady state' volume. The way this impacts your job as an audio engineer is a massive, during the course of the remaining tracking and in the mix.
You gotta start in the room with 'the sound'. Put in some earplugs, get 'Einstein' to play his guitar, until he confirms it is indeed producing "his sound". This is MAJOR, once attained, we now have a starting point. If you can't get by this first hurdle IN THE ROOM, you are in deep shit.... EVERYTHING can be a potential contributor to the problem(s). You gotta find out WHICH things are killing YOU from a seemingly endless list. Don't look to musician, he is hell bent on forcing you to make SHITTY SOUNDING RECORDS.
Pull the cab into a space where you can clearly HEAR it WITHOUT a whole lotta distractions ie. nearby walls, rattling drums or stands, road cases etc. With 'Mozart' still pounding a riff that alternates regularly between the 'chuggs' and some chords, run a few tests. Whip the master gain on the head up and down a little and see at what points the following things start to happen:
1) The speakers in the cab start to 'excurse'. Ya know like an 'move'? Look at the things up close. Put your earplugged head right up next to them and eyeball the speakers. Get a flashlight and peer thru the grille. If you can't see shit, cut the grille away with an exacto knife and have the label pay for a new grille. Have some other bozo twist the knobbie while 'meathead' is twanking and when you start to see the movement, make a mental note of the gain setting at the point of 'baseline excursion'.
2) Have your assistant twist der knobbie around more (while player is STILL endlessly playing pitiful chugs to chord riff) to find out the point of 'Cabinet Involvement'. By observing the cab at different volumes you will find a point at which the enclosure starts to get "involved" in the 'chuggs'. It is NOT always the point at which the speakers 'excurse'. Sometimes it is BEFORE(in master gain volume) the speakers 'bark', sometimes it is AFTER. This is gonna provide you with some clues as to what's going on with how you're going to get 'freaknicks' sound to tape.
Recording distorted guitars. I've always thought making heavy records was one of the most difficult and underestimated tasks in AE. For a bunch of reasons I may cover in these posts.
...That is the first few paragraphs squeezed into 30% of the space. Gimme 50 bucks (and helluva lot time) and I'll do the rest. Deal?
- ahj