Sound Absorption: IKEA Mittzon Floor Standing Panel (+ GIK Acoustic panel).

Greetings audiophiles. Finally, I'm back home in Vancouver after my Asia trip. I love traveling but there always comes a time to look forward to "Home, sweet home." And music to listen to in my personal sound room of course!😌

In this post, let's talk about perhaps one of the most boring things you could buy - a sound absorption panel. Made all the more pedestrian because this one comes from IKEA. At a retail price of US$230 each for the smaller (but IMO adequate for my home audio) 27.5" x 61.75" x 3.125" panel, the IKEA MITTZON Floor Standing Acoustic Screen is inexpensive and easy to find. There is also the larger 35 3/8" x 61.75" model if you prefer for just a little more - US$250.

While this may look boring, I must admit that as I've experienced more and dare say, "matured" in this hobby, the most interesting upgrades do not have to be high-tech active gadgets, bear fancy brand names, or the stuff that seems to capture the latest hype.

No friends, always remember the most important components that contribute to sound quality! Digital technology in particular has reached levels of performance where diminishing returns are quite easily reached these days. Make sure to explore other "domains" and products in your search for high fidelity audio.

As you might be aware, in the last couple of months, I've been focusing more on the audio room. So it seemed natural to take some time now to examine my own space and see if there's something simple I can do to improve things further.

For awhile, I have been wanting to get more absorption into my room. The reverb time in my room - the "RT60" and related metrics - has been OK in that it's <0.5s (<500ms) across the audible spectrum, satisfying basic DIN 18041 tolerances for my size of "music room"; but could still be improved.

Already, I've been using absorption at the lateral 1st reflection points with GIK Acoustics FreeStand panels which made a significant difference. Let's go forward one more step - let's make the front of the room (behind speakers) more "dead" by placing the GIK's up there, while using the Mittzons in the lateral 1st reflection points.

To start, let's look at these new panels. The 27.5" x 61.75" Mittzon stand-up panels each weigh around 35lbs which is quite dense due to the wood frame and fiberboard absorbent material. This is noticeably heavier than the GIK panels which are only about 11lbs each.

Some assembly required. Dark gray panel leaning against
the wall. The lighter "Gunnared beige" cover on the floor
goes over the panel like a sock that snaps into the bottom.

Other than a screw-in metal base, the panel consists of 2 main pieces. A removable beige cover and the actual panel box. 2-persons recommended to put this together but it wasn't hard to do as a 1-person job with some patience.

Here's how it looks completed against my wall:

The brownish bits along the edges are the exposed wooden dowels that allow plastic snaps (included) to let you chain these panels together if you desire. The metal base is quite heavy and it's sturdy, metal edges slightly rounded. They've include some felt stickies to put at the bottom of the base to protect from scratching the floor.

Sticky hexagonal felt bits for the base, plastic attachments if you
want to chain panels, and the usual IKEA Allen key.

Okay, so I assembled a pair of these and they're now in my room. So what? 🤔

If this is a product introduction article (like this) or subjective review, I suppose I can just tell you that the room treatments have "transformed" the sound in my room. Diana Krall now sounds like she's standing in the space singing from about 10 feet away with accompanying instruments even better defined in the sound stage. This has also significantly changed the perceived definition when I listen to multichannel recordings and can now even better pinpoint where those clocks are in the Atmos version of Pink Floyd's "Time".

Of course wrapping up with simple subjective impressions would be way too easy. Let's do it the harder, and IMO more meaningful way! As far as I am aware, all significantly audible changes can be measured with sensitive enough tools, so let's examine these measured changes in my room.

Let's do sweeps using REW under four conditions using my acoustic panels as shown here:

Test system, Paradigm Reference Signature S8v.3 L+R speakers, Paradigm SUB1 front subwoofer, SVS SB-2000 Pro rear subwoofer. Fanless i3-N305 miniPC, and Integra DRX-8.4 receiver. Measurements with door closed. I have a built-in wood/glass cabinet with CDs, BluRays, various storage on the right hence why I've been using these movable standing panels instead of fixed room treatments.

Notice that I have the miniDSP UMIK-2 omni microphone placed at the main listening position (mid sofa, I've put a blue towel to reduce reflections from the leather sofa). For these measurements let's turn off the Dirac Live DSP room correction. I'll send a sweep to the L+R front stereo speakers concurrently so it sounds like a phantom channel at the main listening position; center, surround, height channels all off. With both front speakers active at the same time, that should excite a bit more of the room than a single speaker sweep.

What was the effect?

I. Time Domain

First, let's start in the time domain because absorption primarily reduces reflections and hence the duration of characteristics like reverberation in the room.

While I'll use the common term "RT60" here and there in this post, realize that this technical term is meant for large rooms with a uniform diffuse sound field. For us in small rooms, recall that we have to deal with the dreaded "Modal Zones" discussed previously and what's more appropriately called a "Quasi-Diffuse Zone". Nonetheless, we can still measure "reverberation time" as reflected in the "decay rate" of energy in our rooms and there are different metrics available. REW recommends using the Topt - a measure of the most reliable linear fit for the captured decay time. Here it is in my room without panels and with them in place at the various locations as shown in the pictures above.

Whether the GIK panels are at the side or up front behind the L+R speakers, we see a reduction of ~50ms compared to not having panels in the room. With both pairs of panels in play, there's >100ms reduction in maximum RT above 250Hz. My room's Topt is now measuring down to 360ms at the highest point from 490ms without panels.

Notice the other benefit is that the Topt curve is more even/balanced across the frequency range when the absorption panels are added. This more consistent decay across all frequencies means that we don't have "slow" muddy bass decay or exacerbation of "harsh" treble. Arguably, this homogeneity could be more important than just a target Topt number.

There are other ways we can look at time domain change. Here's the ETC (Energy-Time Curve):

1ms smoothing applied to better see the average changes.

With more panels, the rate of descent in total energy across 200ms becomes steeper without as much aggressive or isolated spikes (like that red peak ~10ms). By 100ms, there's about a 5dB spread between the ETC without panels and the combination of GIK + Mittzon.

II. Frequency Domain

Our ears are highly sensitive to frequencies as discussed previously. Since these sweeps correspond to steady-state frequency response, with the change in time domain performance, we should see at least a subtle effect due to changed interference patterns as the sounds are absorbed behind the front speakers and at the side reflections.

For ease of comparison, 1/6-octave smoothing applied.

Yup. The frequency response has changed with both the GIK + Mittzon panels in the room but not to a huge amount as expected. As you can see, without thicker bass traps, these panels affect down to about 300Hz. At frequencies like the 360Hz low-midrange where I have the cursor, there can be up to 2dB change.

IKEA publishes results done with ISO 354 showing the absorption across frequencies - here it is for convenience:

Another interesting frequency correlation we can look at is "clarity"; one of them is the D50 or "Definition" metric which correlates to speech clarity. For us audiophiles, especially those who enjoy vocals, this correlates to improved lyrical intelligibility as well. The higher the value, the better for intelligibility:

Human vocal fundamentals range from about 80-1500Hz with harmonics up to ~10kHz.

With the absorption panels, notice the improvements particularly from 400Hz to 6kHz. These are very important parts of the sonic spectrum stretching from low-mid to the "presence" region, covering the frequencies human ears are most sensitive to. Other clarity measures like C50, C80, etc. also improve in the same way.

In my room, with my rear-ported speakers, placing the panels behind the speakers alone can improve clarity a little, but not as noticeable as placing them to the side 1st reflection point. This might be different in other rooms and with other loudspeakers (directivity will play a role, for example dipole speakers could benefit a lot with absorption on the wall behind them).

III. Frequency and Time Domain Together

Finally, let's put the frequency and time domains together in a chart/plot. Let's compare the spectrograms without panels and with both GIK+Mittzon:

As expected from the data above, while visibly we can see small changes in the frequency energy (ie. the amount of red/orange/yellow), it's the better controlled decay time in the mid-range and upper bass that's most notable (300ms reference line).

The amount of energy in the bass frequencies <100Hz will change once I apply DSP next.

IV. The "cherry on top" - room correction DSP at main listening position

As I discussed a few years back when talking about my sound room, once I've arranged the physical set-up, I'll apply DSP room correction to achieve my intended, typically more neutral, tonality. In my multichannel system, Dirac Live Bass Control has been working well for me (very unfortunate that Dirac ART doesn't seem to be coming to current Onkyo/Integra platforms 🤨). I'll typically use the Dolby Atmos Music Target Curve as my standard listening target consistent with the company's recommendations for Atmos/Spatial music.

Let's quickly demonstrate, here are the "No panel" (red), "GIK + Mittzon Panels" (black), and the "Dirac Live Bass Control + GIK + Mittzon" (green) Topt curves overlaid to show the difference:

Notice that as expected the Dirac Live curve hasn't changed the room reverb time. Likewise the Energy-Time Curve doesn't change much with DSP:

And the "definition" D50 metric isn't affected by DSP across the midrange. Out of interest, let me also show the C80 "music clarity" metric which as far as I can tell is mainly designed to be used in concert halls where something like +3dB might already be reasonable at the listening position:

In a small-to-medium domestic sound room, you should be able to achieve more than +10dB; I'm sitting around +16dB.

From what I've read, one should focus on frequencies >500Hz (green) with this metric. Studios should at least achieve more than +5dB above 1kHz. I've also seen reference to above +20dB being described as "dry" which is not necessarily a bad thing and could be desired in music production; especially if you're working on the Steely Dan kind of sonic clarity! As you can see, I've bought an extra +4dB of "music clarity" at 1kHz with adding the GIK+Mittzon music panels and even a little higher with +5dB at 2kHz; however we might conceptualize this subjectively in our own mind.

While absorption panels primarily change time-domain characteristics, DSP correction is mostly concerned with tightening the frequency response potentially across 20Hz to 20kHz. I like full bandwidth equalization with modern DSP that allow for multi-point averaging and apply frequency-dependent windowing, but I know some audiophiles prefer that just bass frequencies (like below 300Hz) are manipulated. This is understandable since it's typically the "Modal Zone" standing waves below the Schroeder frequency where we hear the most anomaly. DSP can be essential in coordinating the level and phase of multiple subs - like my combination of Paradigm SUB1 and SVS SB-2000 Pro in these measurements:

And here is the spectrogram of my GIK + Mittzon panels + Dirac Live Bass Control DSP:

With DSP active, because we're boosting the sub-bass (below 70Hz), there's significantly more energy down there compared to without DSP shown in the earlier spectrograms.

Let me also add a waterfall plot here. Notice I'm using peak normalization at each frequency, evening out the frequency response to give us a more "apples-to-apples" comparison of the decay times - comparison across 300ms:

I placed a cursor at 250Hz to indicate room modal range below that point. Again, I trust that the improvement in the midrange is clear.

So, is this audible?

You betcha this is significant ladies and gentlemen, even before DSP!

The price for these panels I'm using is around $230*2 for the IKEA Mittzons + $199*2 for the GIK FreeStands - total US$858 + taxes (plus the price of the DSP if you don't already have that feature). At less than US$1k, it's not a lot of money considering the price of many other things in the audiophile world.

It should be obvious that this kind of measurable change is well beyond differences between hi-fi DACs or in many instances hi-fi amplifiers. This is almost infinitely more meaningful than the difference between bit-perfect streamers (which is basically nothing unless there's DSP being applied by the device) or the negligible effect of audio cables. Unless proven otherwise, I would be very suspicious of often expensive "tweaks" like these, or bizarre ones like this.

The point is, guys and gals, if you want to spend some money to verifiably make a significant difference to sound quality, make sure to look deeply into your sound room: the arrangement, and room treatments. Fidelity gains hit a wall of diminishing returns very quickly given the capabilities of fairly priced hi-fi consumer electronics these days like DACs and Class D amps. I think it's simply wise to be aware of that and act on this fact.

As for the IKEA Mittzon standing panels, well, they work. Even without playing music or running sweeps, the hand-clap-in-room-test shows noticeable reduction in reverb time which can be quantified as about a 12% reduction in Topt with just a pair of GIK panels from an untreated 490ms to 430ms, and then a further 16% reduction from 430ms to 360ms peak when I bring the pair of Mittzons in. This is a total of around 25% reduction in peak Topt measure of reverb time. Beyond the single numbers, the decay time is more consistent across the frequencies (especially midrange). This in turn translates to improved resolution with tighter transients, better clarity, and spatial imaging.

As with most things in life, we could overdo room correction for 2-channel stereo systems I suppose if the room is perceived as too "dead", or uncomfortably anechoic, often quantified as RT60 <200ms in an average to moderate sized room; clearly I'm not at risk. 

[With multichannel playback of music and soundtracks, it's better to aim for lower room reverb since the rear channels already contain the spatial surround content. The listener is going to be bathed in the sound from multiple directions so we're not as at risk of feeling the space being devoid of natural/smooth sonic decay.

For professional mixing studios, recommended RT60 is typically 200-400ms.

One more thing, a low reverb time doesn't necessarily benefit every recording. For example, some genres like modern pop and electronica benefit from the reduced "smearing" of fast tempo, dense rhythms, precise synth "plucks". On the other hand, for some acoustic, choral music and orchestral tracks, higher RT60 might add warmth and sense of space with the room reverb; lower isn't always necessarily better, subjectively at least.]

We can see that a change in room acoustics also can affect the frequency response. Indeed, room acoustics affect tonality and "coloration" of the sound. With up to 2dB variance especially in the very important midrange frequencies, I'll remeasure the room to optimize my Dirac Live filters.

The one issue I have with the IKEA Mittzon is that it comes only in "Gunnared beige". I can't fault them for choosing the lighter color as a kind of "neutral" that could work in many brighter work spaces. A darker color would be more fitting for most sound/movie rooms, I suspect. Since the outer cover can be removed for cleaning, I wonder if IKEA or a third party might want to sell alternate colored covers - black, blue, red, lighter and darker options would be nice for customers to better match their space. Alternatively, I suppose one could be crafty and use acoustically transparent decorative fabric to make a form-fitting outer layer.

Let me know if you're aware of any options to easily change the appearance of these Mittzon panel.

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Let's end with some music from The Cranberries' 1993 album Everybody Else Is Doing It, So Why Can't We?. Recently, the 2026 25th Anniversary Deluxe Remaster was released with new mixes by the original producer Stephen Street. Also available in multichannel/Atmos (stereo DR8, multichannel DR14) worth checking out on streaming services like Apple Music.

It's nice to hear remasters and remixes of older material like this where improvements have been made to clarity, dynamic range (improved percussion), and an expanded sound stage with more subtle depth. They didn't go overboard with the surround effects so while there's better envelopment and more defined instrument/vocal placement, this new mix IMO is still very much in the spirit of the original presentation.

Here's "Dreams":

As always, I hope you're enjoying some great music, audiophiles.