Driving 4 ohm speakers

If 'high quality sound' is not the issue, then wire up in series, Alarg's misgivings not withstanding.

Salut, Bob P.

"My question is, can I drive both with this amp at low volumes? In this small space, I can't see cranking up the volume very high. Obviously, I don't want to burn out either my amp or my speakers."

Well, maybe I misunderstood the question...I didn't think the issue was one of 'high quality sound', but convenience.
Oftentimes we make decisions of either. In this case, at low volumes and for an office, I think the best, most logical solution is the switching box.
I read the question, "How can I make this happen?" Not, how will it sound?

I have no knowledge of how well the Arcam would handle a two ohm load. But I want to point out that while putting either a resistor in series or the two speakers in series will result in a functioning setup, it is not a recipe for quality sound. In either case bass damping goes out the window. And in the case of the two speakers in series, if their impedance vs. frequency curves are not identical, frequency response irregularities will result in both speakers.

Regards,
-- Al

If worried,wire them in series>> Out to L200 "+",out the "-" to the L300 "+","-" back to the Arcam.This should present the Arcam with a 6-8 ohm load.

Bryston as well makes multi speaker switching box.

The Arcam, (wonderful gear), probably has enough current so it wouldn't be a problem, so you can most likely do it. However, to be safe, I might put a multi speaker switching device in line. One that comes to mind, is the Adcom. Don't know if they still make it or not. The way it works, as I recall, is that it places a 4 ohm resister in line, so the amp, sees a non reactive 4 ohm load.
This, if still available is an easy fix, and would give you piece of mind.