Anyone have experience with using de-esser for sibilance in home audio system?

I totally get where you are coming from, Stuartk. I have found that even though it is not the "purist" approach, the dBx 231S, 2-channel, stereo EQ unit does a great job at allowing me to reduce (not totally eliminate) sibilance in my hi-end system. It is extremely quiet and sonically transparent and much easier to use compared to digital EQs e.g. Beringher, etc. You can pick one up for about $300 new, and it could be an ear saver for you... I love mine.

@onhwy61

I would start would the EQ first. Try a parametric and gently scoop out the frequencies that offend.  That could be all you need.  

Good suggestion. Effectively, my question about the rooms is getting at exactly the same cause, but this solution does not require inconvenient changes!

@noromance

It can be associated with tinnatus, apparently.

@erik_squires

Don’t have my headphone amp set up, currently but I do hear it through earbuds.

@bojack

Where is it in your signal chain?

The only time I tried such a product was in my guitar rig and it was really noisy but that was many years ago.

OP:  If you can't hear it via headphones then it's a room issue.

@erik_squires 

I will check when I have time but I'll be astonished if i don't hear it with headphones.