What does RT60 stand for?

RT60 stands for 'reverberation time to a 60 decibel decay' — the number of seconds it takes for sound in a room to drop by 60 dB after the source stops. It is the standard metric for how echoey a space feels.

What is a good RT60 for an office or meeting room?

For offices and meeting rooms, aim for an RT60 of roughly 0.4 to 0.5 seconds. Untreated glass-and-concrete offices in Singapore often measure 1.2 to 1.8 seconds, which is why calls and meetings feel hollow and tiring.

Does lowering RT60 make a room sound dead?

No, when treatment is designed properly. The goal is to bring RT60 into the right range for the room's activity, not to remove all reflections. A well-treated office or restaurant still feels natural — just focused and clear instead of washy.

Is RT60 treatment the same as soundproofing?

No. RT60 treatment controls sound inside a room — reducing echo and improving clarity. Soundproofing blocks sound between rooms. Acoustic panels will not stop noise from next door, and soundproofing will not fix a boomy boardroom.

How many acoustic panels do I need to lower RT60?

It depends on room volume, existing finishes, and your target RT60. A small meeting room might need 6 to 10 square metres of absorption, while a restaurant or hall needs far more. Placement matters as much as quantity — panels at first reflections and parallel walls perform best.

Can I measure RT60 myself?

For a rough check, clap once in the empty room. If you clearly hear a lingering tail after the clap, the room is too reverberant for speech. Proper measurement requires a calibrated microphone and acoustic software, but a site survey by an experienced specialist is usually enough to plan effective treatment.

Which panels work best for reducing RT60?

(acoustic material felt) panels, fabric-wrapped mineral wool panels, and stretch fabric track systems all lower RT60 effectively across speech frequencies. suits offices and schools, fabric-wrapped panels suit premium meeting rooms and churches, and track systems suit larger halls.

22 April 2026

What Is RT60 Acoustic Treatment? A Practical Guide

RT60 measures how long sound lingers in a room. Acoustic treatment lowers it to make speech clear and spaces comfortable — here's how it actually works.

RT60 acoustic treatment is the practice of adding sound-absorbing materials to a room so that reverberation time — the time it takes for sound to decay by 60 decibels after the source stops — drops to a level suited for the room's purpose. In plain terms, it is how we stop spaces from sounding echoey, muddy, or exhausting to speak in. For most Singapore offices, restaurants, and classrooms, the goal is an RT60 of roughly 0.4 to 0.6 seconds.

Below, we break down what RT60 actually measures, why it matters commercially, what targets to aim for, and how acoustic treatment is used to hit them. This is the single most important metric in acoustic design — and the one most often confused with soundproofing.

What RT60 actually measures

RT60 stands for reverberation time to a 60 dB decay. Imagine clapping once in an empty hall. The sound does not stop instantly — it bounces off walls, ceiling, and floor, gradually fading. RT60 is the number of seconds it takes for that tail to drop by 60 dB, which is effectively the point where the human ear perceives it as silent.

A short RT60 means sound dies quickly. A long RT60 means sound lingers, overlaps with the next syllable, and the room feels washy. This is why a cathedral sounds majestic for organ music (long RT60) but terrible for a sermon without a good PA system.

RT60 is measured per frequency band (typically 125 Hz to 4 kHz octaves) because hard rooms often behave very differently at low vs high frequencies. A good acoustic report will show RT60 across the spectrum, not just a single number.

Why RT60 matters for your business

Reverberation is the hidden cost behind a surprising number of business problems. When RT60 is too high, the consequences are very practical:

Offices: video calls sound hollow, meeting rooms force people to repeat themselves, and staff finish the day fatigued from effort listening.
Restaurants and cafes: diners raise their voices to be heard, noise builds on itself (the Lombard effect), service becomes stressful, and reviews mention the noise.
Tuition centres and classrooms: students at the back miss consonants, comprehension drops, and teachers strain their voices.
Gyms: trainer cues get lost under music, and coaching quality suffers.
Churches and event halls: speech intelligibility collapses even with a capable sound system.

In every case, the root cause is the same — reverberation time is too long for the activity happening in the room.

RT60 is not soundproofing

This is the single most common misunderstanding we correct on site visits. RT60 treatment and soundproofing solve different problems:

Acoustic treatment (RT60) manages sound inside the room — reducing echo, boosting clarity, improving how the space feels.
Soundproofing blocks sound from passing between rooms — dense walls, sealed doors, isolated ceilings.

Adding acoustic panels will not stop your neighbour's karaoke, and adding mass-loaded drywall will not fix a boomy boardroom. If your complaint is "the room sounds echoey" or "calls are hard to understand," you need RT60 treatment. If the complaint is "I can hear the meeting next door," you need soundproofing.

What RT60 target is right for your space

There is no single "good" RT60 — the right target depends on what the room is for. These are sensible working targets we use in Singapore projects:

Meeting rooms and offices: 0.4–0.5 seconds. Speech should feel tight and immediate.
Classrooms and tuition centres: 0.4–0.6 seconds. Clarity for young listeners is critical.
Restaurants and cafes: 0.5–0.7 seconds. Some liveliness is welcome, runaway noise is not.
Gyms and studios: 0.5–0.8 seconds. Enough absorption to keep cues intelligible over music.
Churches and event halls (speech-led): 0.8–1.2 seconds. Longer suits music, but intelligibility must hold.
Recording and podcast rooms: 0.3–0.4 seconds. Very controlled and dead.

An untreated glass-and-concrete office in Singapore often measures 1.2–1.8 seconds — two to three times longer than it should be. That is why it feels tiring.

How acoustic treatment lowers RT60

RT60 is governed by two things: room volume and total absorption. Absorption is the sum of every surface's ability to soak up sound rather than reflect it. Sabine's formula simplifies it: larger rooms and harder surfaces mean longer RT60; more absorption means shorter RT60.

In practice, treatment means introducing porous absorbers — usually acoustic panels made from acoustic material (), fabric-wrapped mineral wool, or fabric track systems — onto walls and ceilings. The goal is not to cover every surface. It is to add enough absorption, in the right places, to bring RT60 into the target range.

Placement matters more than quantity

Ten panels in the wrong locations will underperform five panels placed well. First-reflection points, parallel hard walls, and large flat ceilings tend to contribute most to echo. A good design brief addresses those first, rather than spreading material uniformly.

Materials commonly used

Fabric-wrapped panels — strong broadband absorption, premium finish, ideal for meeting rooms, churches, and studios.
Fabric track (stretch fabric) systems — seamless wall-to-wall coverage for larger halls and auditoriums.
Acoustic ceiling panels and baffles — essential where wall space is limited or glazed.

How RT60 is measured in the real world

Professional measurement uses a calibrated microphone and either an impulse source (a balloon pop, starter pistol) or a swept sine-wave played through a speaker, with software calculating the decay curve per frequency band. For most commercial fit-outs in Singapore, you do not need a lab-grade test — a reasonable site survey, room dimensions, and an experienced eye are enough to predict RT60 and specify treatment that will work.

If you want a rough self-check: clap once in the empty room. If you can clearly hear a tail of sound lingering after the clap, the room is over-reverberant for speech use.

What good RT60 treatment looks like in practice

A well-treated office does not feel "dead." It feels focused. People lower their voices naturally, calls sound crisp, and the room stops fighting the conversation. A restaurant at full capacity still has energy, but the background sits below the conversation rather than on top of it. A classroom lets the teacher speak at a normal volume from the front and still reach the back row clearly.

That is the real deliverable of RT60 treatment — not a number on a report, but a room that works for the people in it.

Get your space assessed

If your office, restaurant, classroom, or hall feels echoey, muddy, or tiring, RT60 is almost certainly the issue. Send us photos of the space and a short description of how it is used — we will tell you the likely RT60 range, what target to aim for, and what treatment (panels, ceiling, or fabric wall) will get you there without over-engineering it.