On. At least, for what I’ve currently got (a pair of Triangle Celius 202); looks better with them on. Ironically enough, though, the thing that makes me want to keep the grill on is the holes/nuts/wtv that you put the grill into to stay on. If it was flat black, with just the speakers, port and logo, I’d keep the grill off.

Since, like everyone else has already pointed out, the bass is the biggest issue… have you thought of maybe flipping the layout around? But the soundsystem where you’re taking the picture from, and put the sofa/table/etc on the wall-side of the room. The speakers being further away from that wall will likely make a HUGE difference.

Also, seeing that you’re about 4 meters from the speakers, you might want to sit closer to not have to turn them up as loud. Flipping the layout and sitting closer will most likely end the complaining.