In Crysis 1 and 2, when you were in "Armor" mode, you sounded like a battle tank walking. I loved that. My subwoofer would be boom, boom, boom as I walked. However, in 3, there seems to be a general lack of that "oomph" in armor mode. The boom, boom, boom as I walk in armor mode is paltry. Actually, having played through the entire game (great fun btw), there seems to be a complete lack of the "oomph" experienced in the first 3 games. And before someone flames me about having my setup wired correctly, yes, it is, and no, nothing is shorted out. After finishing Crysis 3 I decided to load up Warhead again, just to test and make sure I wasn't going loco. Nope, epic sound onboard. I'm using Logitech Z-5500 Digital system on my PC.
To get technical, there seems to be a lot of high to mids in the game with the bass (explosions, armor mode, etc) being almost non existent. Some of the cutscenes are very high treble and mid. I actually was checking my speaker system to make sure my sub was even on because of the lack of bass in the game. While the weapons have a real kick to them and the gameplay is good, it's just missing that little something extra in the sound department to really make it shake. If anyone knows how to access the sound files and to maybe increase the general awesomeness in that department, please let me know. Even cranking the bass up extra doesn't help. The lows for the bass just simply aren't there.

Did you try slotting the armor module that increases armor strength? I'm pretty sure it increases your footstep thump.

it does slightly. However, like I posted, there seems to be a general lack of lows for bass in the entire game. While everything looks amazing in Crysis 3 and the sound design is superb, the lows just aren't there much.

I have a Krell 300xi with B&W 703's paired to my PC with an external dac. Generally speaking I didn't really notice a difference, sounded good to me. You could be right and I simply didn't notice it yet. It's been awhile since I played 1 and warhead, I did play Crysis 2 last weekend though and it seemed comparable. But honestly I didn't think about it until now, now i'm curious too.

I'm using an HT Omega Halo XT along with the 5500's and after firing up Warhead, it's almost night and day. There really is a HUGE difference in the lows for bass in C3.