3D printed acoustic diffusers

[eldrick 65]

I've recently been using my UM2 to work on acoustic diffuser panels for the window-wall in back of my flat-panel speakers, and came up with these.

The "trees" against the window are five feet tall and made of square printed PLA units of 16 cavities, each square cavity of "random" depth up to 6" deep, then assembled with superglue. The white plastic is just translucent enough that each cavity transmits a unique amount of light from the window behind it, and the resulting colors range from ivory to taupe in the daytime, and white at night. They are rather digital-organic looking, sort of like pixelated videogame trees.

This process took about three months for my UM2, with the printer running 3/4 of the time. It also took about 18kg of plastic at US$50/kg.

The audible results are well worth it, IMHO. The diffusers have essentially removed the wall in back of the speakers, audibly speaking, and give a much greater sense of depth, along with less blocking of background instruments. There is greater separation of instruments, and it is easier to follow a musical line or voice. Not having a coherent echo delayed ~7ms after the sound from the front side of the ribbons has also made the highs noticeably clearer - cymbals and horns are much less fuzzy.

So - a fun experiment that looks nice in the listening living room and sounds great.

 

[valcrow 145]

Wow look at that setup!!

That's incredibly cool! Looks trippy too.

From an audio noob: Why did you go with boxes rather than those spikey shapes I always see in audio booths?

 

[xeno 108]

Fancy setup

and a great way of thinking for using an Ultimaker, did you buy the UM just for this project ?

some more pics would be nice.

 

[Dim3nsioneer 558]

@EldRick: How did you get the sizes of the individual boxes? Do you have a special software for calculating the diffusors?

@Valcrow: The baffles you probably mean are absorbers. These are diffusors that distribute the sound in a way you don't get a clear reflection on the glass front behind.

 

[eldrick 65]

I justified getting into 3D printing mainly to produce a couple of products for sport fencing:

http://stores.thefencingpost.com/pommel-epee-french-grip-melting-pommel-14g-170g/

http://stores.thefencingpost.com/pommel-epee-french-grip-palmel-18g-170g/

but this was always in the back of my mind.

I had been interested in diffusers for some years, but making them from wood, or buying them, was costly and/or a lot of work.

As to the design process, I found designs on Thingiverse.com http://www.thingiverse.com/thing:189052

I tried the various designs (I liked the hexes), and the rectangular one had the most artistic possibilities, as I could fit different sizes together in a pseudo-random way. I had to modify the design for printing, but then just cranked them out scaled to several different sizes and depths. Arrange to suit, and superglue together. Since the key word is "random", the exact sizes and depths of the cells aren't real critical, as long as the depths of the cells are in the ballpark of the wavelengths you are trying to affect.

 

[tinydancer 0]

That's really neat, especially the color spectrum created by the depth of the boxes.