I'm experimenting/prototyping 3D models to passively absorb specific low frequencies, with the idea of reducing fatigue/increasing productivity in the workplace (where making/taking calls is continuous). The 3D models are based off of a research paper by Yong Li and Badreddine M. Assouar, called "Acoustic metasurface-based perfect absorber with deep subwavelength thickness" [0].

Absorbing low (male voice; 80Hz - 300Hz, not including overtones) frequencies normally takes a fair bit of dampening material, unless something like a Helmholtz resonator [1] is used. The paper shows that a ~100x100x12mm 3D printed Helmholtz resonator may entirely absorb 125.8Hz (in an extremely narrow band). I'm uncertain about transmission losses (i.e. volume of the frequency perceived behind the material).

So far, I have created/vibe-coded a script to take the inputs: frequency and tile dimension (it's square). The output is a 3D object (.stl) which can be printed.

Today I tested my 3D model, which roughly resembles the model in the paper (1mm roof & floor as opposed to 0.2mm, because of printing difficulties), by using a DIY'D impedance tube and publicly available software [2]. The print was meant to be tuned at 125Hz, but results showed 131Hz and absorption factor of ~0.42 (lower number as opposed to 1.0 may be due to inexperience with all of this; it may be due to an imperfect test setup).

My impedance tube is made from 96mm (inner) diameter PVC tube, a Visaton KT 100 V 4 Ohms speaker, an amplifier, Motu M2 audio interface, 2 Behringer ECM8000 measurement mics and some 3D printed adapters (to hold the speaker and sample).

Nothing to concretely publicise or share so far, but am thoroughly enjoying the process of digging into a field (acoustics) completely new to me, solely out necessity and/or frustration in the workplace.

Should anyone be interested, I will share my project with HN once it has progressed to where I have something written up or worth sharing.

[0] http://dx.doi.org/10.1063/1.4941338

[1] https://en.m.wikipedia.org/wiki/Helmholtz_resonance

[2] https://mathworks.com/matlabcentral/fileexchange/931

Naive question but what would be the advantage over traditional sound isolation? (such as in music studios)

These subdomains/sites are most likely misconfigured in such a way that malicious actors are able to redirect to/host anything they wish.

There was a blogpost here on HN about this, showing that (Roblox/Robux) scams were also seemingly hosted on .gov sites. I can't find that post anymore.

Here is a publication related to what you've found: https://cofense.com/blog/threat-actors-exploit-government-we...

I think you are right. A bunch of them appear to be some sort of redirect attack (I'll have to read that link you posted). In other cases I see the just upload files directly such as: https://www.rld.nm.gov/wp-content/uploads/2025/06/z7ot3u38jf... or in that original link I posted it looks like they took over the entire subdomain somehow.

I have quite a few more examples but they are too explicit to post.

My thought on this matter is, if we can't get this contained now on .gov websites then how will we be able to handle malicious spammers when they fully realize the power of AI driven spam attacks? I think things will get out of control real fast very soon.

I guess at least the EU are lining up to put up an iron curtain once they get all the locals KYCd for EUnet.

https://news.ycombinator.com/item?id=44168134

This looks great. What is the reason for adding the https://sso.tax? Why did you make SSO an enterprise feature?

Is it due to some (technical) reason that would require a monetary compensation to be profitable?

SSO has security benefits (on top of the maintainability aspect) which would also benefit small businesses.

To be honest, we're still finalizing our long-term pricing details. For what it's worth, "Sign in with Google" and "Sign in with Microsoft" are available to all users, and we'll prioritize additional canonical OIDC providers as demanded (let us know what you need!). 100% agree with the security benefits here. The SSO reference on our pricing page specifically applies to SAML-based IdPs, intended for customers who require further customization re: auth and provisioning strategy.

I hadn't the time to look around further, so I missed the Google and Microsoft SSO login options. As long as those are/remain free, there is no SSO tax.

I will have another look when I have more time, thank you.

SSO tax seems like a very reasonable price differentiation method to me. Most of the price increases on sso.tax are quite reasonable for a company that needs SSO (most companies I've worked in don't bother until they are above 100 employees, despite what that site says).

> most companies I've worked in don't bother until they are above 100 employees, despite what that site says

Companies don't "bother with" SSO because using SSO is expensive, since every product charges more for the privilege. Otherwise there's no reason why a 2-person company shouldn't be using SSO from the get go.

There are many small businesses that outsource their IT to managed service providers, but are understandably limited in their budget.

In my opinion, SSO tax results in arbitrary denial of employing best practices for these businesses.

Passwords are evil, because people generally don't care about security or don't have the capacity to employ proper hygiene around passwords. This likely means that SSO tax indirectly contributes to an increased number of account compromises (especially in small businesses, because more limited funds means more limited security; they're low-hanging fruit for bad actors).

The alternative is that the starter pricing tiers are more expensive. Pick your poison.

> SSO tax seems like a very reasonable price differentiation method to me

Security is not a differentiation method. It's table stakes for any technical product. That's what the above linked website explains.

> Security is not a differentiation method. It's table stakes for any technical product.

Security as table stakes, sure. SSO, certainly not.

It's an additional cost, last I checked it was between 10$ and 20$ per user per month if you take the cheapest option and outsource it.

This whole notion of "Unless you meet this security standard that 99% of products don't meet, your product hasn't met table stakes" is nonsense and needs to die.

SSO will get cheaper in the future; for now it's hard for a product development team to justify getting 0$ in revenue just because of some purity test by irrelevant folk on the internet.

We will have to agree to disagree on whether SSO is security or not.

> We will have to agree to disagree on whether SSO is security or not.

It's not a binary flag, it's a spectrum. "Defense in depth" is a thing, and that means a layered approach to security.

Just because a product is missing SSO does not in any way mean that that product fails any security check.

IMO, holding the position that not having SSO is the same as not having security is unreasonable.

Missing SSO does not magically make the other $FOO layers of your security vanish into the ether.

Running my own keycloak or another ory hydra is a boring task. Locking SSO behind some arbitrary scale and raked up price takes sales away from you. It’s a matter of perspective.

> Running my own keycloak or another ory hydra is a boring task.

Simply running keycloak is not sufficient for SSO.

An SSO implementation may take months of dev time (i.e. $50k, minimum, considering cost of dev hours spent on it, and opportunity cost of not having those devs putting those hours into features).

And after you have done that, it remains an expensive feature - it's a high-touch feature that will eat product support time like you wouldn't believe.

Outsourcing this is still the cheapest option, and it still costs more than the product itself in many cases.

I don’t understand your point. My question is: if the service provider offers SSO as an additional feature, why limit it to certain size of a client? Their service supports it. Why cannot my two persons company enable this feature? My two persons company can run my own keycloak and use it as an OAuth provider in your product all right. If you need months of dev time to enable SSO on my account then say that upfront because I will certainly find a different service provider because you clearly don’t know what you’re doing.

> If you need months of dev time to enable SSO on my account then say that upfront because I will certainly find a different service provider because you clearly don’t know what you’re doing.

If you could do that, you would. The point is that SSO is high-touch and high-maintenance, and the price reflects that.

If it is as cheap you appear to think so, you'll make a killing offering SSO for businesses and undercutting the current providers by (maybe) 50%.

I don't think you are doing that. Maybe I am wrong, but if you are right you're leaving easy money on the table.

If they're offering SSO using a 3rd party provider like Auth0 then they probably have to charge for it because of how expensive it is.