There are so many contributing factors to their sounds, depending on where you want to sound like them.

For Flea, you'll need the following - A Wal Mach 2, An Alembic Epic, A Stringray, A 1960's Fender Jazz Bass and a Modulus Flea with Lane Poors. All into at least a GK 1001RB (I think, could be wrong) and an OBD-3, a Mutron, an AW-3... various pedals.

Take a look at the Muse wikia to see what basses/effects Chris uses. Far too many to count.
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Quote by MaXiMuse
There is an officialy tone thread. It are pretty alot of pages so Chris is probably between. And he uses a Big Muff and an AKAI Deep Impact, to get the TIRO and a double muff for hysteria...

TIRO is actually done on a synth, not bass. It's impossible to get the exact tone from a bass.
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gm jack knows everything
create your own tone

Fender Deluxe Players Strat > Big Muff > LPB-1 > Moog Ring Mod > MXR Dynacomp > MXR Phase 90 '74 > Fender Hot Rod 410 (soon)
Quote by Drozd
Help Please

In short, amp settings are meaningless without taking into account every other tone altering factor between fingers, bass, amp, speakers and environment.
You're not gonna get their exact tone with just some amp settings and pedals. You need their technique and environment, as said above. Example. I'll set my Eq and it'll rock in my bedroom, but I'll haul the amp to church and it'll sound like ass in the big room. Make sense?
Schecter Stiletto Studio 5
Ibanez SRX2EX1
Gallien Krueger 1001rbii
Gallien Krueger Neo 410