Music for Drones Week 2: getting some sounds on tape
This week we decided to record the drones as they flew by a stand mic. We wanted to get a sense of how they sounded, what specific moves (e.g., fast breaking, rotating on the yaw/ around the vertical axis (like a ballerina spinning in a tiny jewelry box), etc.) correlated to what specific sounds, and so on.
We connected a mic to an iPhone, and mounted them on a tripod about 6 feet from the ground. We put the tripod in the middle of Fretwell/Cato/Denny/Storrs quad, and then C flew one battery-long flight, and R flew another. C synched the sound from the mic with the sound from the iPad we used to make the videos. Here are the videos:
DS_1
DS_2
Especially when the drones hovered near the mic, there was something gradual-process-y about listening to the slow, subtle changes in pitch, in harmonization, in rhythmic patterning. Listen for this in DS_1 around 1:33-1:49.
Perhaps unsurprisingly, there weren’t a whole lot of different sounds. There were basically two variables: (1) distance from the mic, & (2) the speed or intensity of the motor. We could get staccatto motor sounds, and we could definitely hear the harmonization of the rotors, which would fall in and out of something resembling a choral unison (maybe this is the equivalent of windshield wipers falling in and out of phase?).
Now, this may be because we were using a small mic that couldn’t pick up the level of detail we needed to distinguish more finely among different motor combinations, rotor speeds, etc. We’re going to use a better mic this coming weekend.
You’ll notice that the drones look a bit different: they have rotor guards, and they have a lapel mic transmitter attached to their undercarriage. (It took us a while to figure out the best way to attach that transmitter. Ultimately we screwed the lid directly to the body of the drone; that way we wouldn’t have to mess with/around the circuit board.) This reduced battery life to about 6-9 minutes, depending on how hard we flew them, how windy it was, and other variables. These extra attachments also made the drones somewhat harder to control; there was a bit more drift.
This made us wonder: What is a “tuned” drone? As we were discussing it, we thought that a ‘tuned’ drone is like an aligned car–it hovers in place when it’s in neutral. C is working on tuning the drones.
We’re happy to report that all four drones are now assembled: (L-R) Pauline, Delia, Laurie, and Wendy. We’ve been flying Laurie and Delia; they’re in regular configuration (GPS mode). Pauline is in IOC/manual, and Delia is in IOC/failsafe. We’re thinking of them as a nest of drones, like a ‘suite’ or ‘family’ of instruments.
This coming week we’re going to record with the onboard mics, and we’re going to build a contact mic. C found a telephone mic, one that amplifies and records electric signal (not sonic signals), so we want to experiment with that, too.
We’re also going to record with a better fixed mic. R developed a list of specific moves (maybe equivalent to a fingering chart?) so that we can get a bank of sounds to use in a concrete-style composition. We’re going to do a dry run of that chart to then prepare to make some high-quality, indoor recordings.