[quote name='Daz39' timestamp='1474632722' post='3139425']
Dim question - 900w @4ohm, but only one speaker output - so you couldn't get 2 8 ohm cabs into it? It would need to be one decent rated cab to make use of that power?
[/quote]
There are (and have been) quite a few heads rated roughly 400-500W into 8ohm, 800-900W into 4ohm. As long as one cab has two sockets connected in parallel, then as deanovw says, you can daisy-chain two 8ohm cabs to give a 4ohm load.