HI again ,flat on bass is 9 0clock or 3,middle fat is 12 0clock,5,treble 3 oclock or 7 ish.
That,s why you cut the bass back you were using your ears ,always the best way I don,t bother where the knobs are .I just twiddle them till I find the best sound I can get on the night but overall I love the terror sound and there is a lot of it.
By the way it,s paired with a SP212 cab and boy can that little box pump up the -was going to say volume but the number crunchers tell you they are inefficient blah blah but gig one- it works with the head.and cuts through no problem with trouser flapping and bowel moving thunder.
The difference between the 500 and the 1000 to try and answer your question is TB 500 and 1 SP212 cab can handle anything and the TB1000 with 2xSP212 cabs could shatter gall stones.
I don,t care about SPL,v-max etc I,ve got ears and bowels that does me-over and out