ALTERING SOUND WITH PHYSICAL OBJECTS

RADIATIORS AND RESONATORS 

Ben Herrington

Pumping sound through mechanical devices (specifically, using sound to vibrate objects in a specific way while simultaneously recording the result) is not new. Mid-century audio engineers used transducers to activate metal plates and captured the result via contact mics. Springs were used similarly (in a smaller form factor) using transducers and pickups. These mechanical techniques (along with echo chambers) introduced reverb to our collective toolkit. 

L. Hammond — Electrical Musical Instrument

The United States Patent and Trademark Office

Storing physical objects like this in today's studio doesn't make much sense if we only think in terms of reverb. Software provides great emulations, and an impulse response enables us to capture and store acoustic characteristics far more conveniently.

But what if we're thinking beyond reverb?

Our recent post about wooden mechanisms mentioned the sound-shaping potential of pairing a particular sound source device with a specific sound-shaping radiator/resonator. To build on that concept, we can introduce mid-century plate/spring reverb techniques to pump pre-recorded or synth-based sounds through anything that effectively transmits the vibration. This technique enables us to leverage the unique physical characteristics of different objects. It adds new mic'ing options and new points for injecting performance. It allows us to react to and play with something physical.

SSI ROUND DUCTING RESONATOR

What might we do with this?

Resonators and radiators can help impart a physical and organic quality to things like real-time synth tweaks. We can very quickly generate volumes of interesting sonic vocabulary from a simple sound source:

This physical and organic quality is indispensable for adding authenticity to sounds in immersive experiences. Ride vehicle sounds are particularly well suited to this kind of treatment. While none of us have jettisoned in a spaceship escape pod, we have all ridden in cars and planes. We have heard vehicles resonate and vibrate as different sonic frequencies sweep through them. By building and running our sounds through objects like car doors and hoods, we can introduce sonic elements that share characteristics similar to the sounds riders encounter in their everyday lives — working towards sounds that help convince them that what they hear is authentic. Techniques like this help riders forget that they are hearing a soundtrack and help fully immerse them into the experience.

SSI RESONATOR FOR SPACE THEMED COASTER VEHICLE

On a smaller scale, sending sounds to this device made from electronic salvage adds an authentic sounding panel resonance to UI sounds:

This panel's satisfying array of chunky knobs and switches adds a performative aspect. A piezo mounted to the back of the panel can feed a modular synth rig for processing and triggers, with the modular output then going back to the panel speakers:

We can also perform resonators and radiators in a way that achieves more esoteric results. In this example, friction mallet groans on an exposed piano served as source material:

After basic pitch shifting, I played the sounds back through a flex sheet resonator as Roy manipulated and undulated the sheet:

These are a few examples out of many.