Hi Flecko
These are the output figures I got from my F4 when fed with my dac-ah......I didn't include the wattage calcs but the ooutput voltages shown are into ariel mk6c which average about 6ohms...
the spl from the F4/Ariels is more than enough for me in average room conditions, especially considering the ariels are no more than 93db.
Ed
ps .... ran the f4 at a friends recently - fed by beresford dac (no pre, just cd into dac)into lowther ex4s OBs and couldn't run with the volume right up. He has an above average size room, at least 6m square.