Pass XA 30.5 with Revel F 208 ?

The XA30.5 is underpowered for the Revel F208 or F206 unless you like to listen at really low volumes. Yes, the XA30.5 will put out more power after it leaves class A, but it's unlikely to really go above 60 wpc. Revels are not the easiest speakers to drive and as Elevick points out, Revels can be quite content with 400 wpc. I drive a pair of Revels with a Pass amp that puts out 300 wpc into 4 ohms, and even then in my moderately sized living room, I think the tank is a little light on the octane.

Tls49-

The calculator you provided a link to is useful and in my experience, accurate. I can be listening at levels averaging 80 dB but with music with real dynamic range, peaks will hit over 100 dB. That's the issue the XA30.5 will hit with 88dB speakers. And at my 3.5 m listening distance, that's why I said my speakers sometimes are a bit light on the octane.

Other factor to consider which is virtually never really mentioned is that if you really do have enough power on tap, speakers begins to experience dynamic compression at higher spl levels. Said another way,mspeakers can run out of steam before the amp can.

Were I serious about a XA30.5 I would concentrate on speakers running at least 92dB or more efficiency. The whole pointof the XA30.5 is to run it in its sweet spot, and if you're relying on the power on tap when it crosses over to class B operation, might as well get an X150.5