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

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. 

What volume? A song that sounds great at 95 db might sound sibilant at 105 db. Most speakers can handle normal volumes but the closer you get to ‘The Who live” concert levels the. More important room treatments and component matching become.

If you don’t hear it in vocals on the "Trinity Sessions" by the Cowboy Junkies then you have a dead spot in your setup’s response (just to name something you my have on hand).

It’s there on early original releases (both CD/vinyl).

I’ve found vocal sibilance prevalent throughout my musical library (which spans 60-80 years of recordings) regardless of what my system is/was.

I consider it to be a natural occurrence, and don’t have a problem with it.

DeKay

It all starts with microphone selection and maybe goes downhill from there…

Will have to play Trinity Revisited this eve… 45 rpm, the famous church and nearly so Ambisonic microphone array….