A semi professional studio soundproofing project and help in

[dolbythx]

You have more friends here dolbytx! When measuring SPL the A rating ignores all Bass, all LF. I am in a Prosumer studio, a house in an estate. We are in lockdown so really no traffic or activity outside tonight. My quiet room is measuring (iPhone NIOSH App) 32-35dBC and simultaneously 26dBA. Very quiet, I can hear the hiss of air molecules hitting my eardrums!

Oh sorry Dandan, I forgot you. I looked at it in the daytime and now it is between 34-40 Db when I look at it as DbC.This is a very noisy place. It was 180 m2 empty. Glass is everywhere. We covered a plasterboard wall inside. But the floor is 180 m2 of tiles on a concrete screed. And I can hear your footsteps. There are no voices of speech. But the place is vulnerable. The ceiling is also 10 cm down.What can I do better? It makes me think so much and I despair.

[gullfo]

a thin carpet may help with the foot sounds without significantly removing mid and high freq. a lot of windows - maybe build some interior shutters which will act as window blocks and be easy to open and close. heavy plywood/mdf and on the side towards the window - an absorber to damp any resonances in the space between the shutter and the window glass.

[dolbythx]

The entire 180 m2 area is covered with glass in this way. I covered the glass part of the studio with aerated concrete (380 kg / m3). One side of the wall Aerated Concrete + 7.5cm air gap + 2 gypsum. The other sides are 2x gypsum + 15cm airspace + 2xgypsum. The picture shows the floor. It is covered in this way on all sides. There is a lot of noise and echo in the workplace. It feels like it has never been inside. In its final form, only sudden loud sounds, footsteps on the floor and vehicles playing bass are heard in the studio. other incoming voices are minimal though.
There is a lot of free space outside the room, but first I will think of a thin rug in the room. but should I add some mass underneath? In this way, I can leave a 2 cm gap from the wall and insert electrical cables into it, making it invisible. I think there is not much left I can do. I thought of putting another layer of drywall on the walls. But it is said that it can be worse if damping is not done. Green Glue is very expensive here and I don't know what could be an alternative. If it was cheap, I could apply green glue to the ground.

[gullfo]

for that much glass - you'd be best served by building an inner wall with some small window for light. i'd cover the interior of the glass with a thick soft shaded plastic to damp it and eliminate visibility from outside. then build the wall and have the inner insulation just touching the glass to damp it further. the bass from the passing vehicles and trucks - most of that will come from structural transfer once you have the walls and ceiling mass attached.

you could add some rebonded carpet foam on the floor + 2x 20mm plywood. that may help a little.

[dolbythx]

The window system you said yes would be nice, but it's too late. Unfortunately because I was afraid, I covered all the cheeks with a gypsum wall.
I used 40 kg of rock wool for the ceiling. I will nail wood for the diffuser effect. How much area of ​​the ceiling should I cover?
I will add plywood as you said for the floor.

[gullfo]

similar to the walls for coverage would be a good start. maybe some photos of the current state of construction as well to help answer questions.

[dolbythx]

Sorry, it's a little late. Average 16-17 m2. Almost all of the voices are coming from the ground. I hear conversations from the store below. I'm listening and the voices are always coming from below. Do you think if I raise 20 cm, can I lower the resonance from the ground? What route should I follow?

[gullfo]

one thing to check - is the window/door the source or is it truly via the floor structure? you might invest in a stethoscope to determine where it is coming from. it may be from the walls as well if the transfer is via the structure. or it could be wrapping via the window (which would be much easier to correct).

[DanDan]

+1 Stethoscope, but a hard contact one.... https://www.drapertools.com/product/545 ... tethoscope

[dolbythx]

The sound is coming to the door from the far place and from below. I slept on the floor. I listened with my ear as well. I know who the talking person is

[gullfo]

i would fix the door first and see what's left. any shared ventilation?

otherwise isolation of the floor, if it's already transmitting just voices, could lead to an significant expense. barring the desire for cost, maybe you could try adding a layer of rebonded carpet padding with 2x MDF or cement board to create a decoupled mass barrier - but if this is structurally transferred, then the walls will also be in play.

[dolbythx]

I don't want to avoid the expense. It is difficult for me to pour extra cement for decomposed structure. Do you think it's a bad idea to raise it with a wooden frame? I can separate the walls with pads. It's ridiculous but among the expensive things here is the rebounded sponge. Rock wool is cheap. Green glue 22 euro. 1 euro = 10 liras. Too expensive for me. Wood is cheap.

[gullfo]

what other options for a soft (relatively) non-porous decoupling? sheets of neoprene? other carpet pads? a frame floor will become resonant unless you can fully damp it (so filled with sand is one option)

[dolbythx]

I think have a rebounded foam, pa elastomeric foam, Soft quilt Fiber, Rubber products, Sheep wool, rock wool, kanuf mineral wool. How high is the separation required when I am going to decompose? Sand can be a heavy-duty option for an undercoat.
There are not many options. Should the aim be in the form of damping between the mass without leaving an air gap? Would it be a bad idea to raise it 20 cm from the ground with the carcass and fill it with mineral wool?
I am very ignorant about the ground and cannot find an answer.

[gullfo]

the air gap would be the problem. the rebonded foam or recycled rubber etc are generally soft enough to be spread out and still be resilient with the added mass and equipment, people, etc. the sand - would be my last option in this case.