I have owned the SL280 and then the SL260 which were speakers that put the Signet name out there for loudspeakers. The SL266 came out a couple of years later and was also well reviewed but not as publicized. I haven't heard that model. The 280 and 260 used a SEAS metal dome tweeter and I think the 266 used a soft dome. Both the 280 and 260 could be a little bright sounding but were quite musical overall with excellent detail and superb mids. I suspect the 266 is another winner. They are fine single wired if your amp and source are decent.