Basement cinema - Sound insulation

Hello community, I would like to ask how to soundproof a basement cinema (especially bass) or what materials are available for this. Thank you very much!

The best sound insulation (for low-frequency sound) is only a room-in-room solution with decoupling in between. Everything else is just sound optimization within the room.

Good morning KingSong

Acoustic engineer, then I am perfectly taken care of with you!

In the meantime, I also see that bass is my enemy in the house and it is not really controllable. I have considered a room-in-room solution, but so far I have failed because the original room is not large. How do you see it, how much space / distance / air cushion? does the room-in-room solution need to work, and how is something like that built?

Alternatively, which materials absorb, with which could I at least achieve some reduction, or is that basically not possible? Every decibel (of bass?) counts for me that I have to reduce in the home theater room in order not to disturb the family. If a reduction is possible with some effort, I’m in, if it is just fooling oneself, pointless.

Thank you!

So if the room does not allow for a room-in-room solution, I would try the following. Take a look at the Lignotrend acoustic elements. They also have an acoustic calculator on the site. Such acoustic elements with a thick mineral wool insulation behind them will definitely turn your room into a sonic and visual experience! But be careful, the better the room sounds, the quicker you notice if the speakers are crappy. However, you will only moderately control the transmission of low-frequency components to the rest of the house with this, but it’s better than nothing.

I once worked for a while in a recording studio that was located directly (50m) next to an S-Bahn track. It was more about preventing anything from outside from getting inside. This was achieved, but only through R-i-R, where the inner room was mounted on rubber feet and completely decoupled from the rest.

What can possibly already help: decoupling the bass-producing furniture from the floor.

This is not only supposed to bring acoustic improvements, but also prevents the sound from spreading directly in the masonry.

Whether this is a problem for you can be tested quite easily with old, thick carpet scraps, thin mattresses, or the like. Simply place the sub and speakers on them and compare.
As a permanent solution, there are quite a few options on the market ranging from cheap rubber feet to expensive spike systems.

However, this does not help against airborne sound. For that, suspending the ceiling with air and then mass (bitumen boards on a supporting structure or the like) and (for good sound in the cinema) another layer of air in the form of pyramid foam might help.

Thanks guys for your information! The Lignotrend walls look very appealing and expensive.

FYI:
Basement room
- Precast concrete basement (reinforced concrete)
- Outside Styrofoam, bitumen, stud mat, gravel backfill, drainage all around
- 2 DM100 pipes to the outside
- 1 10x10cm opening in the technical room
- 2x 100x60 basement windows
- Floor tile, underfloor heating
- Connections for water, sewage, Sat, web
- Empty conduits in all 4 corners for hanging speakers
- Interior walls approx. 10cm thick
- Not rectangular, 2 slopes on one side
- Door in the sloped wall
- Screen opposite the sloped walls
- Seats by the sloped walls

Currently:
- Ceiling with cheap ceiling panels

Unfortunately, I do not have permission to post a photo, but maybe that will come later.