School me on cabs

monquixote

I'm always really suspicious of those donut things. 

Do they really work?

JCA2550

Yep! providing you use the right acoustic foam and get the measurements right. I must have fitted 10 or so and really like the results. It also means that you don't have to be as fussy about where you put the cab/combo. Just fitted one this weekend to a rather excellent and dirt cheap V30 loaded Harley-Benton (Thomann) 1 x 12, worked a treat paired with my Martamp V6-20 head, perched on top of my bass combo. I play bass and guitar in CarnaC, my current band, we're a 6 piece so space/footprint is an issue.

Danny1969

The higher the frequency the more directional it is. So if you tame the highest frequencies by absorbing them with foam then the output will contain less top end  and therefor not be so directional or "beaming" 

That's the theory I think 

hywelg

I like open back (oval port) vertical 2x12's and IME these can be very very nearly as good as a 4x12 given the right speakers. I made one for a mate who runs a studio and we put it up agains his 1960a and with an EV and a Gold in it it was just as good. A lot easier to transport , takes up much less gig floor space, you just need the right sized amp to sit on top of it if its too wide it looks cack!!