It's actually because it wasn't recorded properly. His sound runs through multiple channels and on almost every occasion that they've had live recordings, the wrong one has been recorded. That's how you get this and the Coachella sound. You're only hearing half of his tone.
His bass sounded incredible when I saw them in Vancouver circa 2012 - the midrange cut right thru you in a way that isn't captured on any live recording I've heard. Unfortunately Seb was wasted out of his goddamn mind to the point where he could barely stay upright behind the kit. A drunk singer is one thing, a drunk drummer is another thing entirely. Jesse was pissed, and played the second half of the gig passive-aggressively staring at his amp. I honestly expected them to break up again after that tour. Thankfully they didn't, and I got to see 'em again a few years ago, in much better form. The bass tone clobbered me just as hard the second time around!
00:39 Intro 01:27 Turn It Out 03:45 You're Lovely (But You've Got Lot's of Problems) 07:02 Dead Womb 09:47 Going Steady 12:43 Romantic Rights 18:18 Cold War 20:53 Blood on Our Hands 23:20 Black History Month 27:58 Go Home, Get Down 30:46 You're a Woman, I'm a Machine 33:28 Little Girl 37:56 Pull Out 40:10 Do It! (Badass outro at 42:18) Encore: 46:15 Mother (Danzig cover) 47:41 Losing Friends
I agree they should be having a blast with it, but as a bass player I have to admit I'd be too mesmerized to do anything but stare for a good part of it all