ROOM 1 :
Cellar/basement/laundry room of an apartment building.
This space is the communal basement and cellar for the entire building (10 apartments). It is on the -1 floor, underground. It is composed of different small-sized “rooms”, all adding up to around 25 sqm.
The entrance of the space feels like it should be echoey, but it is not. There is a continuous background noise from the washing machine and dryer, creating a sort of dead and boomy atmosphere. Every sound becomes a bit muddy, toned down from the materials of the space, but also the humming from the machines and the heater. It seems almost cavernous, and being underground with no connection to the outside reinforces this feeling.
These two “rooms” are quite similar in atmosphere. Very boomy and boxy, the sound does not echo, and everything feels absorbed. You can still hear and understand the size of the room, you can also hear how far you are from the laundry room and how many walls separate you from it.
And finally, the laundry room. You can hear it the second you step out of the elevator (when the machines are turning). It is loud, dense, with a lot of different sounds and frequencies all merging. There is this constant whirring, mixed with the clanging and rattling of the metal from the machines and the splashing coming from the pipes. It is also very hot in the room, making it rapidly overstimulating.
ASSIGNMENT 3 :
Analysis of a clap :
Found a delay of 0.09 s for 30 dB, so a total delay of (0.09 * 2) = 0,18 s
By putting the measurements in a calculator, with a RT Goal of 0.2s :
ROOM 2 :
Elevator
This space is way simpler than the basement, but I felt it was interesting to compare the two and to understand the full auditory experience of going to the basement.
This elevator is about 1.5 sqm, all made out of metal, except for the floor, which is made out of a sort of resin.
The sound here feels metallic, almost robotic. When the elevator does not move, the ambience is dead, boxy, and a bit sharp in some ways. There is not much echo, the sound is clear and the room feels small.
When the elevator is moving, the ambient sounds of metal clanging, thumping from the doors and whirring of the motor, cover the voice quite easily. On top of this, there is the voice annoucement and dings that emphasizes this robotic atmosphere.
Overall, the auditory experience of going down to the basement is quite dense, with mostly low frequencies, thumping and rattling.
FINAL ASSIGNMENT :
The choosen room for this assignment is the room D24.1 on the D floor of the HIL Building. This room is currently 13.5 m x 9.7 m x 4.8 m, which results in a total volume of 630 m3. The total surface area is around 490 m2. The floor and ceiling are made out of concrete, the north facing wall is made out of glass panels and the 3 other walls are made out of plasterboard. This room is currently used as a an office/computer room with a few tables and chairs. It also had some suspended ceiling panels.
Looking at the freequencies relevant for general conversation (so from 500 to 4000 Hz), we can check if the reverberation time is adequate for an office space in this room.
Looking at this graph, we should be on the A3 line : “Communication intensive usage with several simultaneous speakers spread throughout the room”. With a volume of 630 m3 ; the T(target) should be around 0.75s. We can see with the data received from the different receivers that the T30 is way too high, nearly twice as the one recommended.
We can also check for the desired reverberation time with this equation ; giving us a result of 0.73s for a volume of 630m3.
Using this equation (B4 & height over 2.5m ; in this case, for a proper room acoustic, the surface of absorption in the room should be at least around 80 m2.
With the absorption coefficient and the different areas that are currently in the room, we can see that we are missing bteween 11 and 24 m2 of absorption surface for the room to respect a reverberation time of 0.75s.
That is of course if we want to keep it as an office. But if we want to transform it into a yoga studio / relaxtion room the reverberation time can be closer to 0.9s ; meaning the wanted area for absorption panels needed is around 70 m2, so close to what we have.
Although for a yoga studio, it would be nice to add a mirror on one of the wall. We can add it to one of the plasterboard wall (either east or west) but not in front of the glass panels, otherwise it would create a lot of reverberation and flutter echo between the two.
Adding a mirror to the eastern wall (half the height of the wall so 2.4m), this would result in turning this 47 m2 plasterboard wall into 23.5 m2 of plasterboard and 23.5 m2 of glass. Changing these new datas we get this :
So now we have to compensate for this new mirror wall, and add round 15 m2 of absorption material in the room.
To do this, we can add a curtain in front of the glass wall to block the light coming in for deeper meditation or relaxation. We can do a 3m high curtain, so light can still come in but it will block the view and direct sunlight from coming in. We can use this type of curtain that absorbs the frequencies we want to tackle. We can use 2 fullness to be sure the curtain always has folds even when closed.
Adding this curtain would result in adding 3m x 13.5m =40.5 m2 of absorption material when closed – the coefficient of absorption for a curtain of that weight with 2 layers is around 0.45. But it absorbs more the high frequencies, meaning it is around 0.2 for the low Hz and around 0.5 for the high Hz.
Results with curtain closed
This is good, but only works when the curtain is fully closed. If it is opened, so around 6 m2 :
Results with curtain open
So that means we still need to put some absorbtion panels on the opposite side of the mirror in order to reduce the reverberation time when the curtain is open.
To do so, we can add some acoustic panels like these ones, a bit seperate from the wall (20cm) so it follows the green curve :
With 6 m2 of these, this is the most balanced outcome, trying to tackle mainly the high frequencies btween 1000 and 2000 Hz :
Results with curtain open + acoustic panels
For comfort and visuals, we can finally add a thin cork flooring that does not change the reverberation time compared to the concrete flooring that is currently there.
With both these additions, the finals data seems a bit too overcompensating.
Results with curtain closed + acoustic panels
But that allows the room to be very versatile. It can accomodate a dance group with music when the curtain is closed, a yoga class when the curtain is half closed and a meditation session when the curtain is fully open, in full immersion.
These acoustic modifications allow the room to be used in many different ways, always relating to dance / yoga / meditation, a space out of time for overworked and stressed scholars 🙂
Here is a quite render of what the room would finally look like :
