Straight ‘B’ cabs are rounder and fuller sounding.
Angled ‘A’ cabs are tighter and tiny tiny bit more breath and high end.I have 10 Marshall 1960 cabs here in my live room of various types. Black Back 55hz, Green Back, Vintage 30 and G12 75’s
5 are the B type and 5 are the A type.
One of my favourites out of all of them, I have never looked to see what is in there and I don’t want to know. ?It’s pre JCM800. I suspect they are Black Back but someone could have swapped all the speakers out. Sounds really nice though with my Mesa Mk3 amps.
Thanks, man. Even after all these years there are so many things I don't know about all this stuff.
The only Marshall cab I have (couldn't bear to sell it in the Great Post-Kemper Amp Purge) is a newer 1960A from the 90s with V30s. I haven't run full stacks since the 70s but now I wish I'd also bought the B cab so I could hear the difference.
And yeah, sometimes it's more fun to just enjoy the magic than trying to understand the magic.