Acoustic/Soundproofing Curtains

[Fried Chicken]

The upstairs home theater room gets accessed from the back via stairs whose room geometry makes installation of a door particularly difficult. The top stair is "inside" where a doorframe might fit. Doesn't matter, point is: I have a door-sized opening for which I need soundproofing.

I currently use a literal mattress that I slide closed much like a caveman might move a gigantic stone to the entrance of their cave. It's not an elegant solution and leaves an opening at the top of the.... portal.

Are there soundproofing curtains that work? Is this one of those things for which one has to spend a fortune to get anything usable? Could I conceivably create my own, and if so, what sort of fabric/material would be good for this?

I've done the usual search-engining, but they don't work as well as they did in the early 2000's.

 

[m. zillch]

The upstairs home theater room gets accessed from the back via stairs whose room geometry makes installation of a door particularly difficult. The top stair is "inside" where a doorframe might fit. Doesn't matter, point is: I have a door-sized opening for which I need soundproofing.

I currently use a literal mattress that I slide closed much like a caveman might move a gigantic stone to the entrance of their cave. It's not an elegant solution and leaves an opening at the top of the.... portal.

Are there soundproofing curtains that work? Is this one of those things for which one has to spend a fortune to get anything usable? Could I conceivably create my own, and if so, what sort of fabric/material would be good for this?

I've done the usual search-engining, but they don't work as well as they did in the early 2000's.

I pretty sure curtains just as thick as your mattress should work equally as well.

The reason sound absorbing/blocking materials work well, such as fiberglass, is due to its abundant interstices*. The sound has no straight path so it instead bounces around between the millions of internal surfaces and at each bounce it loses some of its energy, which is dissipated as heat.

*a fibrous or air pocket filled structure akin to the inside of an English muffin