I just moved to a new location and now have my Energy RC-10 speakers on my desk. The desk backs a wall, leaving the speakers with 5-6 inches of space behind them. Is this enough stand-off distance against the wall? I dont know what the minimum space is.

These speakers are rear-ported. They come with a foam insert for the rear port for when the back isnt open spaced. My question is just that: how much space is enough "open space" to avoid using the foam port blockers?

I run these speakers off a 15w Sonic Impact T-Amp; not a ton of power but more than enough to be very loud, considering the small room they're in.

I'd say that's about minimum. Usually, when rear ported, about a foot is recommended.

Using the plugs will reduce the bass extension by basically defeating the tuning of the port.

Bryan