I have a hughes and kettner tube 50 head and a london city cab with original 70ies celestion greenbacks.
I love the way the greenbacks sound on the clean channel but on higher gain levels they don't give a lot of bass and a lot of gain (even with my gibson les paul).
So I'm looking for some new speakers in my cab or a whole new cab.
I would like the speakers to sound darker, have more bass and also have a better palmmuted sound.
I play sludge metal/doom/post-rock in a band and on my own just some classic rock and metal.
My budget is money I can get for my old cab + 200eu.

What would you suggest?

I play sludge metal
^the problem is here
Nah, jokes man, whatever floats your boat

Ummmmm, you're looking for massive but tight low end i take it, try and hunt down and old 80's Mesa Cab with Celestion Black Shadows.

Honestly the tightest bass out of a speaker I've ever played, like a V30 on steroids without the obnoxious mid hump.
Gibson Les Paul Standard
Gibson Explorer New Century
Gibson RD Artist
Fender American Standard Telecaster


Framus Cobra
Marshall JCM800 2203 - 1960A


Crybaby 535Q
Rockbox Boiling Point Overdrive