RT60 in a Home Studio: What It Means and What It Doesn't

RT60 gets thrown around in home studio discussions as if it's a single, precise, universally meaningful number. In a small room, it's genuinely useful — but with a significant asterisk that most guides skip entirely.

What RT60 actually measures

RT60 is the time it takes a sound to decay by 60 decibels after the source stops — essentially, how long a room keeps "ringing" after a sound happens in it. A shorter RT60 means a more controlled, "dead" room; a longer RT60 means a more reverberant, "live" one.

The Sabine equation

The standard way to estimate RT60 from a room's construction is the Sabine equation:

RT60 = 0.161 x V / A

where V is the room's volume in cubic meters, and A is the total absorption — every surface's area multiplied by how absorptive that surface's material is, summed together. More absorptive surfaces (soft furnishings, acoustic panels) lower RT60; more hard, reflective surfaces (bare walls, glass, hard flooring) raise it.

Target ranges by use case

There's no single "correct" RT60 — the right target depends on what you're doing in the room. Commonly-cited starting ranges: roughly 0.2-0.4 seconds for mixing, a slightly tighter 0.2-0.35 seconds for mastering, and a shorter still 0.15-0.3 seconds for a dedicated vocal recording booth. General listening rooms can comfortably run a bit longer, up to roughly 0.5 seconds, without feeling problematic.

The part most guides skip: small rooms break the assumption

Sabine's equation assumes a statistically diffuse sound field — sound energy spread fairly evenly around the room, which is a reasonable assumption in a large room with a lot of independent reflection paths. A typical home studio is not acoustically diffuse, especially at low frequencies, where individual room modes dominate the response rather than a smooth, even decay.

There's a specific crossover point for this: the Schroeder frequency, roughly calculated as 2000 x sqrt(RT60 / Volume). Below this frequency, you're really hearing discrete room modes, not reverberation in the textbook sense, and RT60 as a single number becomes progressively less meaningful. For most home-studio-sized rooms, this crossover frequency sits well up into the range that matters for music — meaning a meaningful part of what you hear isn't accurately described by a single RT60 figure at all.

This isn't a reason to ignore RT60 — it's a reason to treat a calculated RT60 as a genuinely useful planning estimate, and a measured one (with an actual microphone and impulse-response software) as the more trustworthy number when the two disagree.

What actually changes your RT60

Primarily, added absorption: acoustic panels, bass traps, thick curtains, carpet, and even furniture all add absorption and lower RT60. Removing hard, reflective surfaces (or covering them) does the same thing. If your calculated or measured RT60 is above your target range, the fix is more absorptive surface area — see how many acoustic panels do I need for how to size that.

Calculate yours

Studio Music Tools' RT60 Calculator uses the Sabine equation with an editable, per-band materials database (14 common surfaces and treatments across 6 frequency bands), and calculates your room's Schroeder frequency automatically so you know exactly how much to trust the result for your specific room.