For my first assignment, I decided to expand on “I am sitting in a room.” I wanted to compare how a feedback loop would be impacted by placing various drinks between the speaker and mic.
My setup was as follows. I had a cardboard box. In opposite corners, I placed a diaphragm speaker and a simple cardioid mic with a foam filter. I would create my wall of various drinks between the speaker and mic, and close the box. For the input sound, I used a clip of a trap artist named Famous Dex recording ad-libs for a song of his. Why? Cuz it’s funny.
For the liquids, I chose to use Spindrift and Almond milk. Why? Cuz I like those drinks. The containers and method by which they were set up were also different, which I expect to impact the output.
Here were the results of each after 10 iterations.
SPINDRIFT
Audio:
Spectral analysis:
ALMOND MILK
Audio:
Spectral analysis:
My breakdown
With the Spindrift, you can see many spikes in the frequency analysis. It’s also somewhat understandable, and you can hear the original sound to some degree. I think this is because of how I set up the cans of Spindrift– there were three different methods by which sound could pass through– Aluminum, the liquid, and air (there were gaps between the cans). Because of this, many different frequencies were able to find ways through the barrier and stay inside the system. In fact, I had to turn down the amplitude often to avoid clipping, because the system’s amplitude was not stable.
With the almond milk, there was less flexibility for ways the sound could stay in the system. Because of this, there is a spike at a particular frequency (about A#7), which, I guess, is the almond milk frequency. You can hear this in the sound as a cool whistling tone. In contrast with the spindrift, I actually had to turn up the amplitude of the sound, to prevent it from becoming too quiet. I think that may be the reason you can hear some glitches in the sound. Also, since most frequencies are quickly dampened by the system, Dexter’s voice is practically unrecognizable.
I found this to be a super cool project; one variable I did not consider was that the amplitude would be unstable. In retrospect, this totally makes sense mathematically– unless the amplitude was totally unchanged in each iteration, it would exponentially grow or decay. I expect to use these principles in some of my music; feedback systems in live performance, in particular, seems like an area of interest for me.
More audio clips
Spindrift rounds 4, 6, 8.
Almond milk rounds 4, 6, 8.