I just picked up a Fender 200 combo (v3), and love the tone. However, just for fun (and to hear what it sounds like!) I was thinking of adding my 410 cab via the extension speaker output on the back. However, that output clearly states that it requires an 8 ohm speaker. My 410 cab is 4 ohms. How likely am I to damage the amp section by running the 4 ohm extension cab? Might it be okay at low volumes but a problem at higher volumes? Thanks for any thoughts.