I don't have sibilance problems, are my speakers dull?

While I am no expert sibilant is the result of having a peak in the upper midrange (somewhere between 3.5-6kzh).  

Well designed speakers should not have sibilant issues no matter how revealing. The worst offenders I have come across are mid to lower model B&W speakers and several Sennhizer headphones. I have never had an issue on anything else. 

I saw that thread too, assuming it’s the recent one about Men at Work’s “Down Under”.  I have the vinyl and have played it on the Cadenza Bronze cartridge and never noticed any sibilance, which I relate to a distorted “s” sound.  I brought it out and gave it a spin on my current Goldring 1042.  The cymbals are very prominent and Dry, no body at all.  The singer “s” sounds are slightly elevated but not distorted or distracting.   Some would call that sibilant.  It’s definitely in the recording/mixing.

Then again, it's men at work. So there's that......

Grab yourself a pair of Tekton Moabs Erik....Should sort you right out!

A lot of the early pressing CD’s had the issue.
They simply took the original master for the LP and dropped it onto the CD format.

The end result was a lot of sibilance and extremely dry sounding, bright recordings.

Later re-masters of the original analog recordings, specifically mixed for digital format (CD) eliminated much of the issue.

If your system and speakers are fairly accurate, it won’t be hard to test/prove out.

As for your speakers, they should pretty much be reproducing what they're fed.