ᐅ Is using KALLAX as a sound absorber in a home theater effective?

Hello everyone,

I am currently considering whether the IKEA KALLAX shelf is really suitable as a sound absorber for a home theater. My room is relatively small (about 15 m² (160 ft²)) and I mainly want to improve the reverberation time and make the sound overall clearer, without having to buy professional acoustic panels.

So here is my specific question:

Is the KALLAX shelf, when lined with acoustic fabric or similar materials and maybe filled with books or other stuffing, a sensible option for sound insulation or absorption in a home theater?

How does the construction especially affect sound absorption in the bass range?

I look forward to your opinions, experiences, or alternative suggestions for better sound in a small home theater. Thanks in advance!

Kla48 schrieb:
Is the KALLAX shelf, when lined with acoustic fabric or similar materials and maybe filled with books or other items, a practical option for sound insulation or absorption in a home cinema?

It’s great that you are diving so deeply into this topic! 🙂 I think it’s fantastic when people get creative and use furniture like KALLAX as sound absorbers. Bookshelves already do a good job of reducing mid and high frequencies, especially when they’re fully packed.

You can cover the shelf with acoustic fabric and then stack foam or mineral wool behind it – that works really well against echoes.

However, in the bass range, KALLAX is rather limited because low-frequency sound carries a lot of energy and requires heavier, deeper traps. But as a combination of furniture and absorber, it’s super practical! You get furniture and improve your sound at the same time – great!

Give it a try, it will definitely help! And above all, it’s fun to be creative ;-)

LEMAN schrieb:
In the bass range, the KALLAX is rather moderate

I would like to add exactly that.

The KALLAX shelf can indeed help with the absorption of mid and high frequencies – the porous materials behind the compartments (acoustic fabric, foam, books) reduce reflections and reverberation. However, bass usually passes through because low frequencies require resonators or thick materials that can absorb bass waves.

If you mainly have bass issues, you should additionally plan for bass traps, for example in the room corners. The shelf can be supportive, especially when filled in a way that absorbs a wide range of sound.

Note: The stability and how well the fabric is secured are important to prevent new resonances. A properly set up KALLAX will definitely improve your sound, but it does not replace a professional setup.

Kla48 schrieb:
How does the construction method affect sound absorption, especially in the bass range?

Regarding the construction method: A KALLAX shelf is made of particleboard, which is relatively thin and has open compartments. These limit the absorption of low frequencies significantly, as bass energy requires very high mass and/or large volume to be noticeably reduced.

The shelf’s absorption in the mid and high frequencies can be improved by filling it with books, acoustic panels, and covering it with fabric, but measurable bass absorption remains minimal.

In general, sound absorbers made with thick mineral wool or specially designed bass traps are better suited for this purpose.

If you are looking for a cost-effective improvement, using a KALLAX as a supplementary element can be helpful. However, for deeper bass control, it is not very effective.

LEMAN schrieb:
You can cover the shelf with acoustic fabric and then stack foam or mineral wool behind it – this works really well to reduce echo.

I can confirm this – I fitted my KALLAX in the home cinema with foam and acoustic fabric.

The sound became clearer, and above all, speech intelligibility in movies improved significantly, which was the most important thing for me. But as already mentioned, the bass issues didn’t disappear; I had to solve those with additional corner bass traps.

For me, the most important thing was that with a piece of furniture you already have, you can also take the room’s acoustics into account. It simply makes the room more comfortable, even though bass still needs to be addressed separately.

It would be great to know whether you have already integrated the shelf or if you are still in the planning stage?