Actually most 2x15's from the 70's, and especially the V4B 2x15, would probably kill most modern 10" cabs in terms of efficiency. Where modern speakers win out is in power handling and excursion, since they are designed to be installed in ported cabinets from the ground up. There's a lot of fuss made over efficiency specs, which, like 'peak power handling,' is generally a spec so finely made, it's damn near a lie. What a cab does at 1kHz, where the spec is most often measured, is as Dave says, meaningless to bass players.
Look, I'm sure your are correct, I'm not going to argue.
I'm just trying to understand why people are saying that 100 tube watts is not loud enough. My experience with this head is the opposite. I have plenty up my sleeve playing through a pair of 2x10 cabs with a 7 piece band (including 2 guitars, keys, sax), with the guitarist right next to me playing a cranked Super Twin (180w). It's all good :-)
