Where to Put Acoustic Panels: Placement and Layouts

Put the first acoustic panels on the side walls, where sound from your speakers or TV bounces once on its way to your seat. A mirror and a patient friend will find those spots, or Plan in 3D will find them around your own sofa, doors and windows. After that, the wall is mostly a matter of composition, which is the enjoyable part.

Where to put acoustic panels first: the side walls

Sound from each speaker reaches you twice: directly, then again off the side wall. Take speakers 2 m (6.6 ft) apart, your seat 2 m from each, in a room 3.6 m (12 ft) wide. The bounce travels 3.12 m against the direct 2.00 m, so it arrives about 3 milliseconds later and only about 4 dB quieter (distance alone; speaker directivity ignored).

A 3D view, from above and behind the seat, of a room 3.6 m (12 ft) wide. Two speakers 2 m (6.6 ft) apart each send a 2.00 m direct path to the listener and a 3.12 m path off the side wall. A Surge Pro felt panel in Silver Nimbus hangs at each mirror point, where the bounce lands. The bounce arrives about 3 ms later and only about 4 dB quieter. — The worked example seen from above. The bounce travels 3.12 m against the direct 2.00 m, so it arrives about 3 ms later and only about 4 dB quieter (distance alone).

That is far too soon to hear as an echo, so your brain folds it into the original. This is the precedence effect: the first arrival sets where you hear the sound, and the late copy is merged into it. The cost is focus. A voice that should sit dead centre gets wider and blurrier.

Why so fussy? With your eyes closed, you can tell when a finger snap in front of you moves by about one degree, partly because your brain notices when one ear hears it about 10 microseconds before the other. By that standard a reflection 3 ms late is an age, long enough to smear a singer between your speakers.

EBU Tech 3276, the European Broadcasting Union's standard for reference listening rooms, asks that reflections in the first 15 ms be at least 10 dB below the direct sound, from 1 to 8 kHz. From distance alone, the example room would need to be just over 7 m (23 ft) wide. Few living rooms are.

A panel that absorbs 90% of the sound reaching it cuts the bounce by 10 dB. Felt gets close in the mids and highs: on its 35 mm air-gap spacer, Surge Pro's laboratory absorption coefficient is 0.84 or higher in every third-octave band from 400 Hz to 5 kHz (NTOU, ASTM C423-22). At 250 Hz it reads 0.59, and less again in the bass. So a panel at the bounce point cleans up voices and detail, and leaves the low end largely as it was.

Close view of the edge of a black-framed Surge Pro panel, held off a terracotta wall by a round spacer. — Surge Pro in Silver Nimbus from the side, standing off the wall on its air-gap spacer.

The mirror trick for first reflection points

Sit where you listen. Have a friend hold a mirror flat against the side wall at the height of your ears and slide it slowly along. Wherever you see a speaker in the mirror, that is a first reflection point. Mark it, then repeat for the other speaker and wall; with a TV, look for the screen. Of the two pieces of equipment, the friend is usually the harder to source. Cover each mark with some panel to spare, since nobody sits perfectly still. Find the bounce. Put a panel there.

Plan in 3D does the same geometry around your own furniture, doors and windows. It marks each first bounce on the walls and ceiling, and every + puts the next panel on the loudest one still uncaught. It finds the bounce points; it does not prove a layout sounds best, because its placements have not yet been measured in a real room.

When a sofa, TV or window owns the reflection point

A sofa against the side wall is easy: the bounce lands above it, at ear height, and the panel goes there. A window, a door, a TV on that wall or a tall bookshelf is harder, because a panel cannot go there. Slide the panel just past its edge so it still covers part of the spot; Plan in 3D does the same.

Two framed panels of beige felt with sweeping curved ridges, and the edge of a third, hung on a plywood wall above a dark sofa, with an acoustic guitar resting on the cushions. — Wave in Sandstone above a sofa.

Should panels go at first reflection points at all?

Not everyone thinks so. Siegfried Linkwitz, co-creator of the Linkwitz-Riley crossover, argued that absorbers there take the top off a reflection and leave the rest, so it no longer matches the direct sound. He preferred side walls left alone, absorption behind the listener, and speakers that send the same tone in every direction. Felt absorbs strongly from about 400 Hz up and much less below that, so his point applies here too, above all with speakers like his. A box speaker already sends a duller sound sideways, so its reflection was never a faithful copy, and he wrote that box speakers seem to do best in deader rooms. With dipole or omnidirectional speakers, try the room without side panels first.

There is also taste. Floyd Toole's research found many listeners enjoy side reflections as a sense of space. Some people like the extra width. If you mix, or want every voice pinned in place, you probably will not.

Ceiling clouds and corners

The ceiling has a first reflection point too. A panel hung there on a Cloud Kit catches it; Plan in 3D hangs clouds 25 cm (10 in) below the ceiling. No laboratory test exists for a hung panel, so the planner rates a cloud with the wall-mounted data and says it likely absorbs more at low frequencies than that shows. Nobody has measured a cloud against a wall panel, so no advantage is claimed here. A cloud is a place for felt when the walls are spoken for.

A dark-walled music studio with a row of ribbed beige felt panels hung on wires below the ceiling as a cloud, and more ribbed panels on the walls behind the desk and beside the window. — Rhythm Pro in Sandstone hung as a ceiling cloud in a studio, with more on the walls.

On a Corner Kit, a panel mounts across a corner at 45 degrees with a cavity behind it. That mount is untested too, so the planner rates it with the same wall-mounted data and says it likely absorbs more at low frequencies than that shows. No corner advantage is claimed here either.

Acoustic panel layout ideas: five layouts with panel counts

Once the bounces are caught, the remaining panels mostly work on the echo, which depends far more on how much the room absorbs in total than on where each panel hangs. So they can go where the wall looks right. The layouts below use the Modular Series, one with a Wave set from the Art Series, and Plan in 3D can turn a layout into a cart from what is in stock.

The mirror pair (2 panels). Two Rhythm Pro 2′ × 4′, vertical, one on each side wall at the mirror point.
A run behind the sofa (4 panels). Four Surge Pro 2′ × 4′ in a row, tops on one level line. The wall behind your head is where even Linkwitz wanted absorption.
Centrepiece and field (7 panels). A Wave set flanked by four Surge Pro 2′ × 2′ in the same colourway, two stacked each side.
A frame around the TV (4 panels). A Rhythm Pro 2′ × 4′ either side of the screen and two Rhythm Pro 2′ × 2′ above. This one is for the echo and the eye: the TV's first bounces land elsewhere.
A cloud over the dining table (4 panels, 4 Cloud Kits). Four Rhythm Pro 2′ × 2′ hung as a square, centred over the table.

Four square light grey felt panels with raised curved lines, hung in a two-by-two block on a terracotta wall beside a taller panel of the same design, with studio equipment blurred in the foreground. — Four Surge Pro 2′ × 2′ in Silver Nimbus hung as a square, beside a Surge Pro 2′ × 4′.

How far apart should acoustic panels be?

Spacing is mostly visual. The Art Series installation guide hangs a set of three 550 × 950 mm panels 25 to 75 mm (1 to 3 in) apart, so a set takes 1.7 to 1.8 m (67 to 71 in) of wall. At 25 mm a set reads as one piece; at 75 mm, as three. Spacing also helps a little: sound bending round each panel's edges is absorbed too, so spaced panels absorb more per panel than continuous coverage. That edge effect is part of why laboratory values can pass 1.0.

Two sets of three 550 by 950 mm panels drawn to scale. Hung 25 mm apart, the set takes 1.7 m (67 in) of wall and reads as one piece; hung 75 mm apart, it takes 1.8 m (71 in) and reads as three. — A set of three 550 × 950 mm panels at each end of the installation guide's 25 to 75 mm range.

How high should acoustic panels be?

A panel that catches a bounce goes where the bounce lands, between the height of your speakers' tweeters and your ears when seated. With speakers on stands the two are close, so centre the panel on your seated ear height, measured on your own sofa. A 2′ × 4′ hung vertically covers 1175 mm (46 in) of height, enough for listeners of different heights. Panels hung for the eye can share one level line, or align with a door head.

What panels cannot do, and what has not been measured

Panels at reflection points buy clarity: a firmer centre, a cleaner voice. They will not cure a room that booms; that depends mostly on where the speakers and your seat sit.
Panels absorb sound in the room. They do not block it to or from the neighbours.
Plan in 3D's echo times are estimates, not measurements of your room. Clouds and corner mounts have no test of their own.

Frequently asked questions

Should acoustic panels go behind the speakers or the TV?

Not first: the bounces that blur the image land on the side walls and ceiling, and Plan in 3D never puts a panel on the wall behind the sound. Behind speakers, pulling them 50 cm to 1 m (20 to 40 in) out from the wall mostly helps the bass. That is another article.

Should acoustic panels be vertical or horizontal?

At a reflection point, vertical covers more heights, which suits one seat. Horizontal covers more of the wall's length, which suits a long sofa where each seat's bounce lands a little further along.

How many acoustic panels do I need?

Two at the side-wall points is the start. The total depends on the room's size, surfaces and use, and how many acoustic panels do I need works it through.

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Fantastic little totebag with a touch of creativity

Some bags look good only when putting down, but the Rothko Tote surely looks great on my back! Not only was it versatile for everyday commute, it is sleek, stealth and stylish, well-suited for most attires dressing up or down. The tote is PACKED with compartments and I like how everything can just sits nicely in their own designated place without dangling. The only thing I would add is a little pen pouch but I guess given the circumstances it might seem obsolete. The bag is not expandable and has a relatively slim silhouette so don't expect to put on a truckload, but if you're looking for a nimble EDC bag paired with a artistic flair, I would 10/10 recommend the Rothko Tote.

Form and Function meet for beautiful panels

Not only are these panels beautiful works of art, their function as absorber/diffuser is top notch. Using in my audio room, the sound is much better with the Massform panels, than my previous panels.

Love them

These are perfect if you’re looking for acoustic panel to bring down sound reverberation and also look cool. I love the quality of these panels. The metal frame makes it very classy and unique. I haven’t installed them on the wall of my game room yet but I can feel the difference already. Packaging was also very professional; drywall anchors and screws were included in the box.

Well Designed and Wife Approved

Anesthetically, the panels are well designed. My wife loves them, although she wasn't much help in choosing the design. The 3 panel application really fits our living living room layout.I hope they provide dimensions that better accommodate a complete wall application down the line

Nice metal frame, beautiful and functional acoustic panels that double as art.

These are awesome panels! With the solid well-built metal frame, they do have a slight weight to them but more of a solid feel than bulky. The panels were all symmetrical and look even lined up on the wall. As far as performance, they do a great job and have comparable results to a 2'x4' owens corning trap. I lined these up along a window frame to cover up the window and to quiet some of the traffic noise and there is actually a significant difference with them installed. Of course the room is already treated, but these not only became the centerpiece, they also helped focus the sweet spot in the room where the vocalist stands. They have become a conversation piece as well. Some people ask if it's just art and I explain to them that it is designed after famous architecture and show them the pictures in comparison. It really does change the point of view and how you look at them. I really do love that they are functional art. It's up to you if you find the price worth it, but I do love how they tie the room together, make for an interesting look, and really help lower the noise floor in the room. I have built regular panels for significantly less, but they weren't as creative, didn't have a metal frame, and definitely weren't expertly cut into a piece of art! The only reason I took off one star was one of the panels actually had pieces of the design loose and floating around in the box. It had become unglued. For the price, I was expecting a panel that would stay together a little better. Nonetheless, I'm very happy with them and a little hot glue fixed it right up as it was obvious where the pieces went.

Where to Put Acoustic Panels, and How to Lay Out the Wall