When you guys say "FR" do you mean "Full-Range", or "Flat Response"? Those are what the FR and FR in FRFR stand for, right?
For what it's worth, pretty much every power amp is full range and any decent one will have a relatively flat response. Guitar cabinets are normally nothing close to full range OR flat response. PA cabs or studio monitors are frequently both FR and FR, though "flat" is a kinda relative term and all. Even speakers that get tested and demonstrated to be flat like +/- 1dB from 20-20kHZ can still sound notably different from each other.
And I'd say if you're not getting a "djent" enough sound, try using lighter gauge strings or tuning your existing strings a couple frets lower and see if that helps any. I can get that kinda sound way too easily with really loose strings, at least the bottom strings anyway... but as already mentioned, the pick attack is a huge part of the sound. Er, at least what I think of when people use the descriptor "djent". But then again everybody has their own ideas about what classification words stand for, so maybe I have it wrong. Like how people use the word "Emo" to describe modern music, even though "Emo" as a genre descriptor dates back to the 80's and 90's and sounds nothing like what people use that word to mean today.
This might be a stupid question but you're playing a lot of single notes on your lowest string and bending them and stuff, right? And also, you've watched videos of Misha playing stuff on YouTube to see how and (very importantly) where he's picking, right? That's a huge part of it right there. Tune low, play single note riffs, bend the notes, pick far from the bridge, bend the end of your notes, all that kinda stuff.
To put it another way, Misha playing a Teisco guitar through a Peavey Rage amp will probably sound more "djent" then like 95% of guitarists playing his guitar through his rig. Y'know? But that's ok. Everybody can have their own sound, just like Misha is probably on an ongoing quest to make his tone exactly how *he* wants it, likewise the rest of us should be on our own tone quests to find our own sounds. Totally totally natural to aim for someone else's sound now and again, especially early on. But it's a nice thing when you're working toward your own sound, and not someone else's.
Okay I'm a sucker, I'll give this away... The single most important thing to learn when you're playing guitar or bass is how to mute 1) strings you aren't playing and 2) a string you played but no longer want to ring out. That is, I believe, the number one skill to have as a player of stringed instruments. The ringing of a string that ought not be ringing will quite literally destroy the note(s) you ARE playing. So that being said, the way Misha mutes is another huge part of the impact of his playing. There's way more to it than all this stuff, and certainly way more than just some settings of some parameters, but hopefully this helps some.
