Speaker replacement and running external cab on HT-20 Combo

[Jvstrat]

I just got an HT-20 combo and I am wanting to put a Vintage 30 speaker in it. Should I get the 8 ohm or 16 ohm model? Also If I have a 2x12 cab and want to run that as an external cab while also using the amps built in speaker, what speaker outs should I use? Thanks for helping

[thephantum]

I would personally put the 16 ohm version in the combo. That way you'll be able to run it and a 16ohm cab at the same time.

Towards that end, unless the impedance of the 2x12 you have is 16 ohms, you will not be able to run the cab and built in speaker at the same time.