How to Build DIY Sound Diffuser Panels in 7 EASY Steps

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Silent Home Hub DIY Sound Diffuser

If you’re trying to build the BEST recording studio or sound system for room acoustics, then we’re sure you’re already looking for acoustic enhancement services.

Some of these are sound absorption materials and bass traps. However, if you focus TOO MUCH on soundproofing, the quality of your sound can get DRY.

For this, you need sound diffusers, and they come in various shapes and sizes.

Sound diffusers and related services can be COSTLY, though. Especially if it’s custom-made, so why not make it yourself?

We’ll show you how to make your very own DIY sound diffuser for a fraction of the cost!

Table of Contents

What’s a Sound Diffuser? How Do Sound Diffusers Work?

A sound diffuser helps spread sound energy more evenly in all directions. It mimics how sound waves bounce in nature.

Sounds complicated? It’s actually fairly simple.

Think of sound as a spectrum.

On one end, you have a sound that feels HOLLOW. Think of a soundproofed room. In there, you’d feel creeped out or uneasy immediately after talking. Dead silence seems to follow you.

On another end, you have a sound that’s so DISTORTED and full of echoes and reverberation.

Think of being in a large and empty room — with hard, concrete walls. You’re definitely going to hear a lot of echoes, right?

In the middle, you have a sound that feels NATURAL. Think of being in a garden, talking with a friend.

The sound there feels so natural, with just the right amount of reflection and echoes, you’re not even going to give it a second thought.

This is what a sound diffuser does. It spreads out sound, so it’s neither dead nor has gone through a lot of distortion and echoes. It only feels natural.

This is why a studio NEEDS sound diffusers. It counteracts the hollow feeling brought about by sound absorption from soundproofing.

Making Your DIY Sound Diffuser Panel

Making your very own acoustic diffuser panels can be overwhelming at first, but don’t worry! Here are the steps to make your DIY acoustic diffuser.

Step 1: Choosing a Design

There are a few factors to consider when choosing a design:

  • Frequency Range
  • Material of Construction
  • Diffuser Placement
  • Type of Diffuser

Frequency Range

Deciding the range of frequencies you want to scatter and diffuse may be a tricky task. If you try to target a range of frequencies that’s TOO WIDE, your diffusion performance will fail.

A good rule of thumb is to stick to a range of 2 octaves at the most.

If you have to cover a wide range of frequencies, then make multiple diffusers to cover the frequencies you want.

Material of Construction

The material we recommend is WOOD. Wood trumps everything else as a diffuser. This is why almost all top-notch quality instruments use wood as their body or casing. Wood doesn’t absorb sound, it reflects it.

We learned this the hard way. And boy were the costs expensive!

As for the type of wood, it mostly depends on preference. Personally, in our experience, we recommend cherry wood if you’re not sure what to start with.

Sound takes on the characteristics of the material it hits. Keep this in mind whenever you’re in whatever environment you are in.

Let’s look at other materials:

Glass

Glass is no good. Try this experiment for yourself to see why. If your car speakers have equalizers, keep the volume down on the bass and the treble maxed out.

You’d feel UNEASY soon after as the sound jumps at you. You’d hear more NOISE than sound.

Foam

As for foams, these are SOUND ABSORBING materials, not sound diffusing materials. Some advertisers and marketers may sell this material as a diffuser, but don’t be fooled! They aren’t diffusers.

Foams only absorb sound, so it DEADENS the room. Good for soundproofing, but for diffusion, NO.

READ MORE: Complete Guide to Making DIY Acoustic Walls Panels for Soundproofing

Where Should I Place Them?

Think of where to place your DIY sound diffusers. The placement depends on the frequency you’re trying to diffuse and the orientation and size of your room.

Most of the time, they’re placed in the front and rear walls as these spots are often stale-sounding.

Type of Diffuser

Choosing the type of diffuser is crucial in designing your DIY acoustic diffuser. The best kind of diffuser depends on your target frequency, as well as the size of your room.

As mentioned before…

  • For lower frequencies, it’s best to go for 1D DIY sound diffusers
  • For higher frequencies, you can choose between the 2D-QRD and the skyline diffuser

Step 2: Determine the Pattern of Your DIY Sound Diffuser

To determine how DIY sound diffusers will look like, you use a diffuser calculator like this one.

With a diffuser calculator, you don’t have to go through all the COMPLICATED math that determines the pattern of DIY sound diffusers.

You only have to input information like:

  • Design frequency
  • Size of your studio
  • Number of wells that you want

Step 3: Gather the Tools and Materials

Once you have your plans for your DIY diffuser, we can now proceed to gather the things needed for the product.

Tools

The tools needed are the following:

  • Tape measure
  • Pencil
  • Sanding block
  • Hand saw
  • Wood glue

QRD Materials

Materials needed for a QRD are:

  • Wooden cabinet frame – think of a rectangular box made out of wood with one open side
  • Sectioning boards with a thickness of around a quarter of an inch
  • Wood blocks that can fit between the vertical wells.

2D-QRD Materials

Material needed for a 2D-QRD are:

  • Wooden flat baseboard around a quarter to half-inch thick
  • Wooden well dividers with a thickness of around a quarter inch
  • Square wooden blocks

Skyline Diffuser Materials

Materials needed for a Skyline Diffuser are:

  • Wooden Flat Baseboard around a quarter to half-inch thick
  • Square wooden blocks – widths are typically around 2 inches

Step 4: Cut the Wood According to Design

  1. Using your saw, cut the wood into each piece that you need.
  2. The length, width, and thickness of your panels and other pieces are determined by your diffuser calculator.
  3. Before you start cutting with your tools, MAKE SURE to use a tape measure and pencil to mark each piece, so you don’t make a mistake.
  4. After cutting each piece, don’t forget to sand it down so that the edges are smoothed out. Don’t go too far in sanding, though, as you might mess up the dimensions.

A piece of caution: this step is TEDIOUS. You will use up a lot of time doing this part, so brace yourself.

Step 5: Assemble the Sound Diffuser

Congratulations! Now that you have gotten through the hard part, we can now proceed with the fun part.

Assembling sound diffusers is fairly straightforward. It’s just a case of putting together the different wooden pieces and panels on top of your base in the pattern from the diffuser calculator.

Make sure you follow the dimensions of the panels from the calculator. DOUBLE-CHECK if the distance between panels and other pieces is according to the calculator.

PRO TIP: To make sure that the pieces stick, use wood glue as you stick the pieces of the sound diffuser panels to each other.

By following the dimensions CAREFULLY and CLOSELY, you ensure your product will be able to diffuse sound effectively.

QRD Assembly

  1. Specifically, for a QRD, the first thing you need to do is insert the vertical dividers onto the base and secure them in place with wood glue.
  2. After that, you need to add the supporting blocks between the dividers to the proper positions according to the calculator.
  3. These pieces should have VARYING widths, so refer to your design carefully.

Alternatively, you can use thin strips of the same size and layer them onto the backboard until the proper height is achieved.

You don’t need the supports in this case, as you are simply using additional layers to increase the height.

This method is even more labor-intensive, but it has better durability and performs well at scattering sound in all directions.

2D-QRD Assembly

In a 2D-QRD, you can follow the assembly for the QRD. The main difference is that the dividers are now vertical AND horizontal, making it a bit harder to do.

However, as long as you have the right tools, we’re sure you’ll end up with products that are just fine.

Skyline Assembly

  1. The best way to start building your skyline is by marking your base into a checkerboard pattern.
  2. Write in each box the length required, so you don’t always have to refer to your design.
  3. This may demand an EXTRA amount of time, but you are now less prone to making mistakes by doing this. In the end, you might actually save more time!

You can also construct your skyline WITHOUT A BASE by gluing the pieces to each other rather than sticking it to a base.

This may be more difficult, but you will also be using less material.

Step 6: Let the Diffuser Dry

If you’re an impatient person, this might also be a hard process for you. It’s important to let the adhesive dry out for at least 24 hours before you move it.

To prevent any accidental nudging from occurring, you should move the drying diffuser to a place where access is difficult.

Step 7: Mount the Diffuser

With all of the other steps done, your diffuser is now ready to be mounted.

Just hang the diffuser according to where you originally designed it for. Depending on how heavy your diffuser is, you can use either Z-clips or heavy-duty picture hangers.

How Do Sound Diffusers Work?

A sound diffuser mimics the natural environment sound waves operate in. Our ears hear sound waves that have been reflected off various surfaces like:

  • Plants
  • Stones
  • Poles
  • Buildings

How Does a Sound Diffuser Mimic This Phenomenon?

Depending on the type, sound diffusers make use of multiple towers or wells of different heights, widths, depths, and spacing.

They may look like just a random pattern of differing dimensions, but they are actually specifically arranged.

How Do You Know the Specific Pattern of the Sound Diffuser?

The specific pattern you are talking about is called the diffusion sequence.

The sequence of specific dimensions of the towers or wells of acoustic diffusers is designed based on COMPLEX mathematical formulas we mortals can only dream of understanding.

All you need to know is that it is based on many factors, such as the environment you will put your DIY diffuser and the frequency range you want to diffuse.

Go back to your acoustic diffuser calculator to determine the pattern that you have to follow DIY-style.

Acoustic Diffuser Types

There is no one specific diffuser type that is the best, and the type of sound diffuser you should use should depend on your needs and preferences.

Quadratic-Residue Diffusers

Quadratic Residue Diffusers (QRD) is a set of columns of wells and troughs of various depths.

After sound energy enters the wells and troughs, it bounces around inside the well and is reflected out in a more balanced arrangement.

This Is Best For:

QRD diffusers are used to control reflections in a room, specifically from rear walls and first reflection points, and are often used for low-mid frequencies.

This type of quadratic diffuser tends to be most effective when there are about 6 feet between you and the diffuser, making it a perfect option for a larger studio room.

Two-Dimensional Quadratic-Residue Diffusers

Instead of a set of columns, a Two-Dimensional Quadratic-Residue Diffuser, or 2D-QRD diffuser, uses a set of squares of various depths to balance out the sound.

Sound diffusers like these provide excellent sound diffusion in the mid to high-frequency range. Also, outside that diffusion range, this kind of quadratic diffuser provides more scattering for better sound quality.

This Is Best For:

These can be installed in your studio room to achieve a more SPACIOUS feel in your room. You would feel less constricted as the sound from a studio with a 2D diffuser feels more natural.

2D diffusers are often placed on the front wall between speakers and on the rear wall to improve quality by avoiding the absorption of back wall reflections.

This kind of diffuser is ideal for a SMALLER space because this diffuser is usually smaller than a quadratic residue diffuser.

Skyline Diffusers

Skyline diffusers are similar to 2D diffusers but with one key difference. Instead of square troughs, the skyline diffuser is composed of blocks of differing heights.

When put together, these blocks resemble a city skyline, which is the reason for its name.

A skyline diffuser scatters sound energy both horizontally and vertically to liven up the sound at dead spots and provide your studio room with a more NEUTRAL and BALANCED acoustic sound.

Just like the 2D diffuser, the two-dimensional scattering of the skyline diffuser broadens the sound depth and makes a room sound larger, making this a good acoustical tool.

This Is Best For:

Similar to the 2D diffuser, the skyline diffuser is usually placed on the ceiling, on the front wall between speakers, and on the rear wall to reduce areas of dead sound in a room.

Lastly, the skyline diffuser is often used for high sound frequencies.

Final Words

Boy and Girl giving a thumbs up

There you have it! Congratulations! Your very own cheap DIY sound diffuser. And just like that, you’ve probably already saved A LOT of money.

Hopefully, this article has equipped you with the skills to build diffusers of all kinds to make your studio as COMPLETE and FUNCTIONAL as it can be.

About the Author

andrea_adams

Andrea Adams

Fidgeting with gadgets and electronics has long been Andrea’s expertise. She has assembled, disassembled, and tweaked almost every type of device you can think of. Through the years, she has come to realize that technology should never be fussy. And that’s where her interest in quiet products stemmed from. She hopes to become your go-to person for insight when deciding on noiseless goods to purchase.