Acoustic Sound Diffuser Panel Tiles - QRD, Sized for A1 mini, MK4 and P1S

A hard, flat wall sends sound back at you as one strong echo. These are acoustic diffusers that you print yourself, and what they do is break that echo up: the same reflection leaves the wall in many directions and arrives at many slightly different moments, instead of all at once from one spot.

Here is what they do not do. A diffuser does not take sound out of the room, and it does nothing for bass, room modes or loudness. Its job is to tidy up reflections, and that is the whole job. There are two series, each in three sizes for the A1 mini, the MK4 / Core One and the P1S / X1, and every size is cut into numbered tiles, so a wall of any width goes together without moving the tiles that are already on it.

Make your own wall in the browser

The quickest way to your own wall is the free Diffuser Generator. You pick the series, how many tiles wide the wall is and your printer bed and depth, and it shows each tile in 3D, how much sense the chosen wall makes, the approximate print time and filament for the whole wall, the calculated band and the wall plan. It downloads print-ready STL, either the whole wall as a ZIP with the plan or a single tile. It runs in the browser and costs nothing.

Open the Diffuser Generator: chronosauros.github.io/diffuser-generator

Why the wells have different depths

The deep series is a row of seven wells separated by fins, and the wells have different depths. Sound that goes into a deep well travels further before it is thrown back than sound that goes into a shallow one, so the parts of a single reflection return one after another instead of together. The deepest well is four units deep and one unit is about the width of a well, which is why a deep tile looks like a set of tall slots.

The depths are not random. They follow a number pattern, the same for every tile, chosen so that the returning sound spreads out evenly and does not pile up in a few directions. A shallow well next to a deep one is the whole trick, and the pattern decides which goes where.

The deep series is the deeper and lower of the two, and the price is printing time and filament. The blocks series is the shallow, decorative one. It is a two-dimensional diffuser made of square blocks of different heights, 13 x 13 of them on the A1 mini and P1S / X1 sizes and 13 x 11 on the MK4 / Core One size, and it is meant for the upper mids and treble. Every block is solid in the file, and the slicer turns that into a light part, which is why this series is the easy one to print and to hang.

Why the tiles are numbered

Seven identical tiles in a row would repeat the same pattern at every tile width, and a pattern that repeats sends the sound into a handful of preferred directions. So the tiles are not identical: each one is the same pattern shifted along by a different number of wells, and the number on the back tells you which is which. Hung in the order from the plan, they break up that repetition, and that is what takes the edge off those preferred directions.

The order also has a practical side. A wider wall adds tiles on the left, so the tiles that are already stuck on never move, and you can start small and grow.

What a sound diffuser changes in the room

Stand in the room and a flat wall gives you the echo as one sharp copy of the sound. A wall of these tiles gives it to you as many small reflections that come from more directions and are spread a little in time. That is the whole change, and I will not promise a particular sound beyond it.

As a rule of thumb, mount the deep tiles with the wells vertical to spread sound sideways, which is what a side wall or a rear wall usually wants. Turn them so the wells run horizontally and the sound is spread up and down instead.

Three printer sizes

Each tile is sized to its printer with a margin on every axis, so it is at least 20 mm smaller than the bed in every direction and does not lift off it. The times and grams below come from Bambu Studio slices of every file on a P1S profile, and the A1 mini and MK4 / Core One tiles were sliced on that same profile too. Take them as a good estimate for those machines, not as a measurement. A whole wall means the widest plan, with every tile number printed once.

• A1 mini (180 x 180 x 180 mm bed). Deep tile 154 x 155 mm and 90 mm deep, 356 g, 7 h 16 min to 7 h 28 min each, seven tiles. The widest deep wall is 107.8 x 15.5 cm, 2.49 kg and 51 h 15 min. Blocks tile 155 x 155 mm and 50 mm deep, 152 to 159 g, 4 h 05 min to 4 h 21 min each, nine tiles. The widest blocks wall is 46.5 x 46.5 cm, 1.40 kg and 37 h 36 min.

• MK4 / Core One (250 x 210 x 220 mm bed). Deep tile 224 x 185 mm and 130 mm deep, 645 to 646 g, 12 h 03 min to 12 h 17 min each, seven tiles. The widest deep wall is 156.8 x 18.5 cm, 4.52 kg and 85 h 00 min. Blocks tile 225 x 185 mm and 63 mm deep, 246 to 251 g, 6 h 06 min to 6 h 14 min each, six tiles. The widest blocks wall is 67.5 x 37 cm, 1.49 kg and 36 h 59 min.

• P1S / X1 (256 x 256 x 256 mm bed). Deep tile 231 x 231 mm and 134 mm deep, 811 to 812 g, 14 h 54 min to 15 h 12 min each, seven tiles. The widest deep wall is 161.7 x 23.1 cm, 5.68 kg and 105 h 15 min. Blocks tile 231 x 231 mm and 51 mm deep, 286 to 296 g, 6 h 58 min to 7 h 21 min each, nine tiles. The widest blocks wall is 69.3 x 69.3 cm, 2.61 kg and 63 h 56 min.

The deep tiles are heavy for their size, because the fins, the floors and the back plate print solid, and the closed air chambers under the shallower wells only remove the solid in between. The fins are 1.6 mm thick and the outer walls 2.0 mm, sturdier than in an earlier version of mine and chosen to be thick enough to stand straight at full height. The blocks are the light series. Both are a lot of printing for a wall, so pick the size by your patience as well as by your bed.

Building a diffuser wall

Every tile has its number and an arrow sunk 0.4 mm into the back, readable from behind, and the arrow points up. The orders below are as you see the wall from the room, left to right, and a wider wall adds tiles on the left, so the ones already stuck on never move. Deep walls are a single row, and more rows simply repeat the row.

• Deep, A1 mini: 4 columns (61.6 cm) 3 7 2 1, then 7 columns (107.8 cm) 4 5 6 3 7 2 1.

• Deep, MK4 / Core One and P1S / X1: 3 columns 2 6 5 (67.2 cm and 69.3 cm), 5 columns 1 7 2 6 5 (112 cm and 115.5 cm), 7 columns 3 4 1 7 2 6 5 (156.8 cm and 161.7 cm).

• Blocks, A1 mini and P1S / X1: start with tiles 1 2 over 3 4, add 5 6 as a third column, then 7 8 9 as a third row.

• Blocks, MK4 / Core One: tiles 1 2 over 3 4, then 5 6 as a third column.

These deep orders changed on 25 October 2026, after a 2D BEM simulation found orders that scatter a little better than the first ones (calculated, not measured). If your wall already hangs in the earlier order, there is no need to move anything.

A deep tile turned upside down has the wells of the tile numbered 9 minus its own number, so 2 and 7, 3 and 6 and 4 and 5 are the same part turned over. If you would rather print four shapes than seven, that works, and only the sunk number will then read wrong.

The wall plans are in the other files as SVG, one for each series, with every size and every wall width drawn tile by tile. For a wall that is not on the list, the generator above builds it for your bed and depth.

Printing the diffuser tiles

The deep tiles stand on their end, exactly as they sit in the STL, so the wells run upward and every layer has the same cross-section. That is why they need no supports: nothing overhangs, and each well has a smooth floor along its whole length. The blocks lie flat on their back, with the blocks pointing up. All of the files were sliced with a 0.4 mm nozzle, a Textured PEI plate and PLA (Bambu PLA Basic), with no supports and no brim, and with the chamber fan off.

• Deep: 0.28 mm layers, 4 walls, 10 % gyroid infill.

• Blocks: 0.20 mm layers, 2 walls, 15 % lightning infill, which supports only the block tops.

The 3MF files are only for the P1S / X1 size, seven deep tiles at 231 x 231 x 134 mm and nine block tiles at 231 x 231 x 51 mm, because every 3MF was sliced on the Bambu P1S profile. The A1 mini and MK4 / Core One sizes come as STL plus the settings above, and with the P1S numbers in the list as an estimate. Bambu Studio labels the first solid layers over the sparse infill as bridges. They sit on infill and not over air, and the largest true bridge on the mesh is the sunk tile number, 0.4 mm on the deep tiles and 4.7 mm on the blocks, but a solid top over sparse lightning infill can sag a little, so keep an eye on the first block tile.

Mounting without drilling

The back is flat, so the tiles take removable picture-hanging adhesive strips. Use strips that are rated together for at least twice the mass of the tile, which is 356 to 812 g for a deep tile and 152 to 296 g for a block tile, and put them near the four corners, away from the sunk number, on a clean, dry, painted wall. Press each tile on for 30 seconds and wait an hour before the tile takes any load. Strips are a poor idea on wallpaper, fresh paint or textured plaster.

Where things stand

Nothing has been printed yet as a full tile. The pictures are renders of the STL files, in filament colours chosen for the picture, and the times and grams are from Bambu Studio slices on a P1S. The geometry was checked on the mesh with automatic tests for heights, dimensions, closed shells and bridges. A mesh is not a printed part, though, so the first real print may turn something up, and I will update this page when it does. The design frequencies and bands in this text are calculated, not measured, because I have not measured these tiles in a room.

QRD maths for the curious

Each deep tile is a quadratic residue (Schroeder) diffuser with N = 7, and the well depths are taken from n² mod 7, which gives 0, 1, 4, 2, 2, 4 and 1 depth units. The design frequency is about 1110 Hz on the A1 mini size, 770 Hz on the MK4 / Core One size and 740 Hz on the P1S / X1 size, and the deepest well is 4/14 of the design wavelength.

It diffuses in a band that is set by the well width at the top and by the width of the wall at the bottom, so a wider wall reaches lower. Around seven times the design frequency the surface acts like a flat panel for a narrow band, which comes with the mathematics and is not a printing flaw.

Each deep tile is one period of the pattern. That makes seven shifts and four distinct shapes, because three of the shifts are simply the others turned upside down. Hanging different tiles next to each other in the order from the plan reduces the periodicity lobes that seven identical tiles would produce.

Learn more about acoustic diffusers

• Diffusion (acoustics) on Wikipedia, a general introduction.

• A brief history of room acoustic diffusers by Trevor J. Cox, from Acoustics Today (PDF).

• Practical acoustic treatment, part 4 in Sound On Sound.

• Room improvement in Sound On Sound.

• Acoustic Absorbers and Diffusers: Theory, Design and Application by Cox and D'Antonio, the book whose formulas these tiles follow.

Licence and credits

This is my own design, not a remix, and it is shared under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 (CC BY-NC-SA 4.0). The geometry and the code that generates it were written with AI assistance, and the AI label on this page is set to Yes.

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