Diffusion

Sound behaves in many ways like light. When you shine a lamp in a mirror the light is reflected. Sound works in a similar way, every hard surface is a mirror for sound. That’s why your voice in the bathroom sounds different from in the livingroom.

Soundwaves are basically particles of air that set eachother in motion, and high frequencies create shorter waves than low frequencies. Absorbtion converts the energy in a soundwave to heat and reduces the energy in a room. That way the room will sound calmer and dryer. For a booth that’s desirable, but sometimes it isn’t. In those situations diffusion is an excellent alternative.

Diffusion implies that a soundwave is reflected, but with different timings or in different directions. Controlled reflections if you will, and they are much less annoying and keep the energy and livelyness in the room. Diffusion in smaller rooms can help making the room acoustically bigger. It’s used in conjunction with absorbtion and low-end treatment.

Diffusers can be tuned to be effective in a particular part of the frequency spectrum. SANDBOX diffusers are built by hand and can be optimised for your room. They can be finished in any RAL colour or woodfinish.

QRD (Quadratic Residue Diffusers) are wells with different depths reflecting soundwaves with slightly different timing differences. That way a mix of slight phase differences occurs, effectively diffusing the sound. QRD’s can work evenly on selected parts of the frequency spectrum and can be used to work either horizontally or vertically, depending on placement. 

By using diffusers we can control reflections in a different way than – or combined with – absorbers. Diffusers are really great on backwalls and primary reflection points. QRD diffusers can also influence the perceived space, i.e. they can make small rooms appear acoustically larger.

One can also distinguish diffusers based upon directonal properties; horizontal, vertical or both. A QRD is regarded a 1D-diffuser, Skyline would be 2D.

Maar er zijn ook varianten waarbij het geluid verspreid wordt door de vorm van de diffuser. Een 1D-diffuser ziet er dan uit als een halve cylinder die horizontaal of verticaal geplaatst kan worden en het geluid verspreidt in het gekozen vlak. 

Een 2D diffuser is meer een halve bol die het geluid zowel horizontaal als verticaal verspreidt. 

In the second half of the last century there has been a lot of research regarding acoustics and diffusers, and that has led to excellent mathematical formulas. With the help of these formulas we can build diffusers that target very specific frequency ranges.

Skyline diffusers get their name from the resemblance to city skylines. They work similar to QRD diffusers, however skylines are effective in multiple directions. Combined with absorbers and basstraps these wooden elements will also help to create a nice look.