Literally amazing. When I connected a pair of these up to my 16W per channel parallel SET integrated, I wasn't expecting much. After all, at just 84dB, they are not very sensitive speakers and so theoretically should be connected to a much more powerful amplifier, not a low power tube amp, particularly a single-ended triode. But I was honestly amazed at how good these little speakers sound regardless. They certainly punch well above their weight with a tonally balanced and totally unfatiguing sound that belies their diminutive size. If you are looking for a smallish pair of bookshelf speakers on firm pair of stands to suit the smaller room, then I would strongly suggest you audition them. How does ATC do it, I ask myself?