CrushingAnvil
Ironically enough, now in Jesus Land
Covenant is certainly faster and more bassy but I wouldn't say heavier. It's all a matter of opinion. The last track "God Of Emptiness" is very brutal tone wise though. I know live their tone is monstrous but like a lot of earlier DM acts the CD quality suffers. I was going for album tone over live tone.
Of course, you're right there, Morbid Angel Destroyed at wacken...but...dude I've heard Suicide Silence and I dont mean to be a dick here but they sound like every other down-tuned Death Core band out there...
I think the notes being played and the context in which they are being played is of equal importance to tone. For instance I straight up don't like the majority of the tones of some of my favorite bands. It's the context in which the tones are used that makes them sound amazing.
If you look at it this way - A 7 string is just a B tuned 6 string with the high E down the bottom
Update: I just watched the video for their song 'Bludgeoned'...
GIVE ME MY FUCKING TWO AND A HALF MINUTES BACK