Let’s get physical (space)

I mean… Let’s talk about sound in the way that provides us with the most physical and tangible approach to it. When we talk about sound, we often do it in terms of frequency: the lows, the mids, the highs… 100 Hz, 1000 Hz, 10000 Hz. Frequency replies to the question: “How often (does air oscillate when excited by a sound wave)”? So when speaking of sound in terms of frequency we talk from a time domain perspective.

Rarely we talk in terms of real-world, anatomic dimension of sound: what is called wavelength. Wavelength replies to the question: “How much physical space is occupied by a single full cycle of oscillation of a given frequency?” As such it is expressed in meters. When speaking of sound in terms of wavelength we talk from a space domain perspective

Each single frequency has its own precise wavelength and one cycle of it occupies a precise space. Given a sound speed C of 340 m/s ( as per International System of Units) at sea level with an air temperature of 15° C (59° F), wavelength L for frequency F can be derived with the formula L = C/F.

So… 100 Hz has a length of 3,4 meters. 1000 Hz is 34 cm. 10000 Hz is 34 mm.

40 Hz is 8,5 meters… 800 Hz is 42,5 cm… 6.3 kHz is 53,9 mm.

As you can see frequency and wavelength are inversely proportional to each other: as frequency raises, wavelength shortens.

I think that’s pretty cool to know… Actually I think it’s great to know about the space “occupied” by sound frequencies. Because after all space is where sound sources live, and it’s also where we operate as audio engineers positioning microphones to capture sound!