Recently acquired a small closed back 12" speaker cab. Tried it (using correct ohm) to a couple amps and it sounds a tad flubby. I think there is some kind of hemp speaker in it. Do ceramics or alnicos sound better in closed back? I know there is a lot of sound and pressure bouncing around in those things. I had 4x10 closed back hundred years ago that sounded decent. But, a 12., not sure. Ideas?