Acoustic Diffusers

What are those acoustic diffusers? You’ve seen them probably many times before (in studios, concert halls, listening rooms or theaters) but you didn’t know what are they really for. These things are mainly made from wood and they usually look beautiful. People use diffusers to improve the acoustics of the specific room.

How do they work?

Acoustic diffusers are different object from plain walls and usually mathematically calculated in many ways to fit your requirements. They should scatter the sound wave in every direction while the energy of that wave remains the same. That’s the main reason why musicians like to use them. If you have a musical instrument, you shouldn’t absorb all the reverbations because it won’t sound as it should. Also , no acoustic treatment will lead to very harsh and not clear sound. The best (and the most expensive) way is to use acoustic diffusers.

Blackbird studio C. The most awesome and complicated build of diffusers that was ever done.

Types of diffusers

There are many types of diffusers. The most popular ones are the Quadratic Residue Diffusers (QRD). These can be 1 or 2 dimensional (so they scatter sound waves only in horizontal / vertical plane (1D) or in both (2D) ). These diffusers are mathematically calculable and you are able to tell the exact specs of the one that you are building.

This is a QRD 17 + 1 diffuser from The number of wells of these diffusers is a prime number. There is a +1 only because they wanted to make it symetrical. The default generated sequence for the well depths was: [0, 1, 4, 9, 16, 8, 2, 15, 13, 13, 15, 2, 8, 16, 9, 4, 1], as you can see, it’s not symetrical so they just added an „extra well“ with sequence number 0 (which means that the depth of that well is 0) to the end of that sequence. This is why they call it 17 + 1. You can calculate these diffusers using the Diffuser Calculator app but there is not added an +1 well. (not everyone uses this, see here, I made this diffuser at home from $15 using my app!)

Now lets see another beautiful diffuser by that page, it’s the 2D QRD N73.

This is one of the most beautiful diffusers that I’ve ever seen. It costs more than $6000 but no doubts about the price, to build this diffuser it can take up to few months. If you think that you have enough time and even tools to build this, then good news for you. You can build that diffuser too using my app. How to build it? Check the section Tips for Diffusers.


To be continued…