End of a long quest to vanquish sibilance.

@stuartk , this was an interesting read. I am happy for you that you resolved the issue. It’s interesting, because I’ve read other posts in other threads by listeners who found squares of concrete as a satisfactory way of elevating their tweeter height; I think I may have read of a reviewer or two talking about that. I am not questioning/doubting you at all; just noting that. I’ll remember it for my own purposes as well. My chair happens to put me at a height that my ears are at or maybe even a bit below my tweeters, and I can adjust by adjusting my slouch.   Not too crazy long ago I was breaking in/auditioning a new pair of speakers, and I think it was a distortion test track on a test CD I was playing with, and I remember thinking that I heard the distortion more clearly when I was sitting up & my head was more forward. Which I guess should maybe equate to my hearing being better in that position? I played around with that aspect of listening for a little bit, but that was driving me neurotic and totally taking the pleasure out of the experience.

Anyway, just out of curiosity, which speakers were you trying out that led you to solving the issue by removing the pavers?

Now that you mention it, on occasion, when I’ve cranked the volume so I can hear it better in another room, I’ve noticed a fatiguing edge. I never turn it up that loud when in my listening chair, though.

As far as the above, not that it applies to sibilance, but back in the 90s, on the weekends when I was doing the majority of my listening, I had my system in the living room and I would be drinking and having a good time during my listening and I would frequently have it cranked up to earbleed levels; in the living room it would sound pretty dirty at those levels, but when I would go out to the backporch where I was barbecuing, it still seemed LOUD, but I thought it sounded pretty good from back there. (Now my system is in a smaller dedicated back bedroom, and the way I listen is considerably different.)

@deep_333

Your interpretation is entirely off the mark.

Maybe consider reading things a little more carefully before jumping immediately to erroneous conclusions.

+1 on that.

I think we can all agree, given the OP’s evidence, that the single one entity causing sibilance, was the use of concrete pavers under the speaker stands. If that is the case, then some quality of the installation must be responsible. I have my own speculations, but does anyone have any specific, um, concrete explanation as to the cause of this effect? I’d love the opportunity to be on-site to find the answer.

@immatthewj 

I'd rather not disclose the make/model of the speakers. They are very highly regarded, as is their builder and I have no desire to raise any doubts about either. Based on what I've read, I'm very much an outlier in terms of how they sounded to me in my room. 

@noromance 

I don't know whether this matters but, due to weight considerations, I actually had two pavers, butted up against one, under each stand. The pavers were textured, so there was a bit of a gap between each pair. 

Maybe this was asked, but if you put the pavers back where they were, does the sibilance return? 

@sls883 

I endured sibilance for a long time. I'm far more familiar with it than I'd prefer to be. It hasn't returned since I removed the pavers. Why would I want to bring the pavers back?