I had a hand wired clone of a blackface Princeton built a few years back and have gone thru quite a number of alnico speakers trying to capture the magic of the circuit with little success. I probably should have tried a ceramic sooner, but I really like alnico speakers in another vintage clone I have (brownface) and thought they would bring the same magic to the Princeton. They didn't, and I'd actually thought of selling the amp because it just seemed so uninspiring when plugged straight in.
I decided to finally try a ceramic speaker in the amp and mulled over typical options, but this 10" 25 watt paper voice coil speaker really caught my attention and I'm so glad I decided to go with it.
It's a super balanced speaker in the amp, without booming bass or strident highs. It's not muffled, nor does it project any unpleasant frequencies.
What it does do is just sound fantastically balanced, and to me, gives off some type of magic or mojo that turns the amp into a real keeper, whether using pedals or not.
Purchasing speakers to try in an amp can be hit and miss, so I hope my experience can help someone else know what might work in their amp and what to expect. Good Hunting!