Hi Guys,
I made a bit different, I have a Catalyst 200, I disconnected the wires from both speakers and using a speaker cable adapted I connected one of the channels into a 1x12 Egnator cab with a Eminence Legend 1228 (8 ohm). Sounds much better, more details and less muddy, but headroom drops a lot compared to 2x12 stock.
After that I connected it into my 212 cab Marshal Origin (8ohm) with 2 Celestion Seventy 80. Well here the thing became alive, a beautiful beast of rock, punchy, beef, defined, sounded as good as my Carvin V3M tube amp in the same cabinet.
I made my tests with very loud volume, and for long time, without any issues and feeling no risk in damaging the amp as it is 4 omh, a set of 8 ohm speaker is ok.
I was thinking on give a try to Celestion FRFR speaker (F12-M150) on it, but I'm not sure if the amp output has some EQ designed specifically to work with that stock speakers, making those expensive speakers sound like lollipop.
Instead I have a powerfull G212A Active Cabinet from Harley Benton (sounds very good), and in this one I may setup the Celestion FRFR ones for an upgrade and more real FRFR.
My conclusion on my Catalyst 200, it sounds amazing with an external cab, a Celestion Seventy 80 seems to be a very good match for the amp.
If anyone has experience with Full Range Celestion F12X-200 or F12-M150 please share with us. :)