My battle with sibilance.

My experience with sibilance is as a live sound technician and in a home recording studio environment.

This article will explain a tool used by sound engineers to control sibilance, a deeser.
https://ledgernote.com/columns/mixing-mastering/de-esser/

I run audio systems in churches where there is a large number of older folks with reduced ability to hear high frequencies. So I feel pressure to provide a generous amount of high frequencies associated with sibilance but without creating an unpleasant sound.

When I am working with a powerful digital audio mixer that has plenty of parametric EQ and deeser or compressor with frequency side chain (explained above) there is little difficulty controlling sibilance.

Sometimes I’ve noticed that sibilance can be controlled by reducing the attack time of the compressor.

For a home situation EQ would reduce sibilance but also hacks the high frequencies (4-8khz) for the entire mix. That is why a deeser is preferable.

If you notice the problem mostly when the volume is loud or when you are boosting the volume of a preamp, maybe the sibilance is causing unpleasant high frequency distortion somewhere in your signal chain.  Be sure to check your signal chain for a volume knob that is too high followed by one that is too low. 

In the case above maybe a tube preamp or tube compressor will create less offensive distortion in the highs while providing some gentle compression. The compressor will likely have an insert so you can use an EQ to turn it into a pseudo-deeser.

Your solution will likely be greatly influenced by your budget. There are plenty of options, including some not included above.

Hi nice tread about a problem, i think we all more or les are battling.
What bpoletti and jrw1971mentions makes a lot of sence to me as well.
could the siblings, that also is a part of the Human voice be an indicator of several diffrent problems in the chain, when they get to hard and excaterated.Its surely also a huge problem in the digital area, where the abselutely pronounce the digitalis in the sound.

I observed that cabels are a huge part of the problem/soulution.
I also had very good results with cleaning all pfysical connectors and adding contact enchaners.
Tuberolling  also makes Big diffrences as well as powerconnector rolling. The same with the fuses.
To hard siblings often makes the limit on How loud you like to hear the music as it gets so umpleasent.
happy listening

I mostly stalk the halls of this forum, but felt like adding my experience here. 

My previous cartridges from Sumiko and Ortofon all had sibilance issues. I noted this to be jarringly obvious on several LPs. The most obvious being a few old Tom Waits pressings and a few of the Nick Cave reissues that came out a few years ago. At some point I just stopped listening to those albums via vinyl and went with the digital version instead. 

About two years back my Sumiko EVO-III cantilever busted for some reason. My friend who owns a hi-fi shop recommended Hana. I picked up the EH. It was great, but still had sibilance issues on the same records, although slightly less. Then the pandemic happened. I decided to give my EH to friend of mine and picked up the MH. Told myself a while back I would never spend more than $500 on a cartridge, but I figured I'd give it a try. I sent my turntable to my friend (he's been setting up cartridges and turntables for decades) and installed the MH. Got my turntable back and my sibilance issues were 99% gone. 

I'm not well versed in all the technical aspects of this hobby so I'm not 100% sure why the MH cured my problems. I know it's a different tip and cantilever than my past cartridges. I honestly don't really care why it worked. Just happy it did. 

Anyway, this has been my experience. I'm not saying a $1200 cartridge will work for everyone, but it certainly worked for me and my system*.

As another note, Perfect Vinyl Forever has what they call the Archival 3.0 cleaning service. That's made a huge difference in sound quality issues I've had on new and old vinyl alike. 

*Pro-Ject "The Classic", Moon ACE, Vandersteen VLR CTs, REL T9, Audioquest (AQ) Niagara 1200, AQ Monsoon AC cables, AQ Meteor speaker cables. 

One should not have sibilance with any good quality phono set up properly unless of course it is on the recording which can be a thing.  
FWIW I have none. Zero nada sibilance with the Denon dl103r in my rig. Been that way for years. Historically the most common cause For sibilance I’ve found over the years is a worn stylus followed by a bad setup resulting in poor tracking.

Sorry to resurrect this thread, but tonight I am reminded of a particularly difficult album to track...without sibilance.

Norah Jones, "Not Too Late"

From the very first song, there is a lot of 'sss' to navigate.  This could be attributed to a 'hot' recording, but if you can get a phono cartridge dialed-in, it can sound wonderful.  For me, it required a combination of high-quality, low-mass cantilever/stylus, along with very exact cartridge alignment (including VTA and azimuth) in order to get a satisfactory result with this album.