Acoustics Based on Volume:
Aluminium
A sphere, a cube and a tetrahedron: three objects made of aluminium, all constructed to contain the same volume. Together they form a new instrument which shows how form changes its acoustic character by using its individual resonance. With the use of electronics, the shapes can be used as instruments or acoustic (reverb) chambers. A work made for both performance and research, with an interest in the language of bodies.
Cube
Content
Volume 14526.78 cm3
Surface 3573.87 cm²
Thickness 1 mm
Mass 954 grams
Material Aluminium
Audio
Feedback frequency 501.3 Hz
Echo time 1.363 sec
Sphere
Content
Volume 14205.78 cm3
Surface 2836.56 cm²
Thickness 1 mm
Mass 742 grams
Material Aluminium
Audio
Feedback frequency 3720 Hz
Echo time 0.901 sec
Tetrahedron
Content
Volume 14163.22 cm3
Surface 4216.17 cm²
Thickness 1 mm
Mass 1133 grams
Material Aluminium
Audio
Feedback frequency 835.6 Hz
Echo time 1.472 sec
To go more into depth I did some research on the instruments with a couple different tests to find information that you normally wouldn't hear just by ear.
I found out that the forms have not just one, but multiple resonating frequencies. I created a feedback loop in order to find their strongest resonating frequencies. The test for the echo time was more complex. I tried different pulses using the transducer, but striking the forms myself worked best, as the strike resulted in the longest decay. After finding the best percussion stick, I struck each form 9 times and calculated the average echo time.
Another test I did was a filter sweep. Here I didn't notice any considerable differences between the forms, except for the sphere. The sphere produces a lower dB and has some notable peaks and one clear peak at its resonant frequency: 3.720 kHz.
Frequency sweep from 200 Hz to 20 kHz, -18 dB
I also let some audio samples go through the forms with the curiosity of how they would be transformed. I used multiple samples, but a hi-hat and a kick sample had the most interesting outcomes. With the hi-hat sample, you see the sphere really popping out in its higher frequencies and with the kick sample you see the tetrahedron having a powerful low end.
Hi-hat sample
