I hope everyone is having a great evening.
A couple of months ago, I came across an audio thread about a product called Holostages, which is a passive room correction device. At the time, there was one user whom touted the devices as revolutionary. This user stated that he has products from LessLoss, SR among other and the Holstages easily outperformed them all at a fraction of the price. The initial response fell well short of acceptance. Honestly- I felt the same way. Seemed to good to be true. How could four little plastic boxes parked around your room with no wires to connect anything to be so effective? As time went on, more users started to respond, all with the same results. OK- my curiosity is now sparked. I am a user of the some of the products the OP mentioned, and found them to have merit. Heart Sound is the company that makes these devises and according to their website the company offers a pretty generous 60 day money back guarantee- so I thought what the heck. I placed an order last week, got a package a few days later with four little black plastic boxes. I followed what others have reported for placement. I put two in the corners of the front wall about 5' high and two on the side walls half way between my seat and the speakers, same height. After about 4 hours, the sound stage expanded in size, but became less defined, kinda muffled with a loss in detailed. I then moved the two on the side walls to slightly behind my seat, still on the side walls. This really didn't improve much, if anything, things sounded a little bright. My amp has external output transformers. So I moved them there, on top of each. OK- this is working. The soundstage grew yet again, and everything became more defined. More density, dynamics, space, realism and oh so smooth. I left them there for a day. Liking what I was hearing, but I figured I would play around with them some more and earlier today, I moved them on top of my speakers. This is truly the sweet spot. It only took about 2 hours for the room to adjust and the sound is far better than anything I've heard in this seat. I have put a lot into my system over the last couple of years. I've run a dedicated power line, which was a huge improvement. I've added a grounding device, room treatments along with upgraded power and IC's. Installed Baach4Mac (intro), Lessloss and SR products. I would agree with the OP of the thread I was reading, these things work as advertised. They are staying put and I'm glad I stumbled onto that thread. Best bang for the buck I have spent on my system. Krissy is the proprietor and has been great to work with.

So what are they?
I went to their website and looked at them and they don't even give a description of what it is or how it works.

For a grand I would at least expect a good story using words like "Quantum" or "Nanoparticles" or even "AI" !

All I'm seeing that a great review by "Mikey the Cop NYC"

At least tell me what it is!

I see 4 screws on top. Couldnt find any cracked open views on the internet for whatever reason.

If I didn't have more urgent plans for a thousand bucks I'd get them and send them to Danny at GR and see if he could upgrade them for me.

PDXDrew:Not discounting your experience but as other members rightly pointed out, the outfit isn’t doing themselves any favors with their website shopfront.  It’s almost if they went out of their way to be cryptic and that solo review by Mikey the Cop NYC—-well, I can’t top what other members have already commented on that front.

That said—while I’m not curious enough to take advantage of the 60 day money back guarantee, I’ll keep an eye out for more info.

I ordered one set.  60 day money back guarantee is always a fall back if these do not work as discussed in WBF.
Bob

Drew, will do. I have DIY QRD-7s on the front wall to see if there is an improvement with the use of these.  I have the WBF in placement both on the front and side walls as well as equipment so I do have some experimentation to do.
Bob