How'd you place the 906? Sounds great.
Didn't like my 906 on my 1960b so much
Pink noise to amp turned up just enough that you can hear it.
Mic at centre of cone then mic pre gained up and sent to ath-m50 headphones.
Got in front of cab and moved mic away from the centre just past first "tone" change away from the high harshness then moved mic away from cab until least amount of ssshhhhh in the high frequencies. Ended up just outside dustcap about 2 inches off grill cloth.
I always mic a cab like this.
Pink noise takes away any other variables and makes it easy once you have done it this way enough times.
Also forgot to mention that I replaced the cones with V30s years ago.
This cab seems to be much more dynamic than my recto cab. The speakers seem to move more and are less stiff. Maybe from being cranked so many times over the years.
I still love the recto cab and use it for metal more than the Marshall.
When I first got the 906 I wasn't that impressed but now it's my favourite amp mic. When you compare to a 57 the 57 sounds brighter and initially better but once you get to the mix the 906 just fits better with less work (for me)
When I teach eq to my students they always think I have taken to much presence from guitars when I cut the 4-5k fizz but I try to explain that it only sounds dark compared to the sound that was too bright. At this point we take a break then listen to it again 10 minutes later with the eq on then when the eq is turned off it sounds obviously harsh and fizzy.
For this band I tried 57, 421, i5 and 906 and the 906 won by miles for fitting in the mix and having best midrange for their tuning, gear and songs.
Sorry for the long winded reply but I find the 57 and 906 comparison very similar because the 57 sounds brighter and clearer but only compared to the darker, with more midrange, 906. Sometimes the 57 works better but recently I usually go for the 906. My 906 revelation came recently when I miced the same performance with lots of mics and listened later in a mix rather than picking the mic straight away.
I set the high switch to centre but must try the other positions and listen later. Just haven't had a chance lately.
Please note that the 906 is VERY different to the 606 or 609 which are both horrible.
John, I know you are very experienced so this reply is not directed at you, apart fromt he initial placement bit.