I have a Marshall M412 speaker cabinet with 4 12" Eminence AX-75 speakers. The problem is the amp sounds like complete rubbish when standing anywhere except off to the side, particularly with any distortion . I've tried duct tape and even making my own beam blockers but I'm still not satisfied. Does anyone have suggestions for speakers or other ideas that might solve the problem?

Get a better cab with speakers that are better.

As you have found out those cabs are horrid. Look for a used Marshall 1960, they run $250+ if you don't mind a cab with some scuffs/torn grill, but works perfectly
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
That beaming effect occurs to some extent on all moving coil speakers. Your best bet is to make sure the speakers are pointing at you at all times, then adjust EQ etc to see if you can get what you want.

EDIT that's not to say another cab might sound better, but unfortunately I don't have any hands on experience with them.
Last edited by tim_mop at Oct 13, 2013,
Thanks for the replies guys. I should be okay just replacing the speakers right instead of getting a whole new cab? or is there some other design flaw about the M412?

And yeah tim_mop I've had this amp for a couple years now and I've tried all kinds of tweaks with the EQ to make it sound okay from the front but to no avail.

Now does anyone have any speakers they particularly like? Something that would sound good with heavy distortion and palm muting of the like.