Noah Bennett
Acoustic Engineer & Room Acoustics Educator | Founder, Reverb-Calculator.com
My name is Noah Bennett. I built Reverb-Calculator.com because the physics of how sound behaves inside rooms is genuinely fascinating, practically important, and almost entirely invisible to the people making decisions about acoustic spaces — from architects designing concert halls to musicians building home recording studios to teachers frustrated by classroom echo.
The central measurement in room acoustics is RT60: the time it takes for sound to decay by 60 decibels after the source stops. A concert hall with RT60 = 2.0 seconds gives classical music its richness and spatial depth. A recording studio with RT60 = 0.4 seconds gives recorded audio its clarity and definition. A classroom with RT60 = 1.5 seconds makes speech intelligibility difficult and teaching exhausting. These are not matters of taste — they are measurable physical quantities with calculable optimal ranges, and the tools to calculate them have existed since Wallace Clement Sabine first derived his reverberation equation at Harvard University in 1898.
Reverb-Calculator.com puts those tools directly in the hands of anyone who needs them.
What I Research and Write About
My work on Reverb-Calculator.com covers four areas:
RT60 calculation and acoustic formula methodology. The Sabine equation — RT60 = 0.161 × V/A in metric units, where V is room volume in cubic metres and A is total sound absorption in metric Sabins — is the foundational formula of architectural acoustics. It works well for rooms with relatively uniform absorption and standard geometry. For rooms with high average absorption (absorption coefficient above approximately 0.3), the Eyring equation — RT60 = 0.161 × V / (−S × ln(1−ᾱ)) — provides more accurate results. I research the derivation, application, and limitations of both formulas: when each is appropriate, what conditions cause each to underestimate or overestimate reverberation time, and how the underlying acoustic physics connects the mathematics to real room behaviour.
Absorption coefficient science and material selection. The accuracy of any RT60 calculation depends entirely on the absorption coefficients assigned to room surfaces. These coefficients — which express what fraction of incident sound energy a material absorbs at a given frequency, from 0 (perfectly reflective) to 1 (perfectly absorptive) — vary significantly by material, surface treatment, frequency band, and installation method. I research published absorption coefficient data from authoritative sources, how to apply it accurately in calculations, and how material selection and acoustic treatment affect RT60 outcomes across the frequency range.
Room design targets and acoustic specifications. RT60 does not have a single correct value — it has optimal ranges that depend on the intended use of the space. Recording studios and vocal booths need RT60 between approximately 0.2 and 0.6 seconds. Classrooms need 0.6 to 0.9 seconds for speech intelligibility. Home theatres work well between 0.3 and 0.5 seconds. Concert halls for orchestral music need 1.5 to 2.5 seconds for acoustic richness. I research these target ranges, the acoustic standards that define them (including ISO 3382 for room acoustical parameters and ISO 12354 for building acoustics), and the practical acoustic treatment decisions that bring a room within its target range.
Room acoustics education. Behind every RT60 calculation is a set of physical principles worth understanding: how sound energy propagates through an enclosed space, why hard parallel surfaces create flutter echoes and standing waves, how early reflections and late reverberation have different perceptual effects, how room volume and surface area interact to determine acoustic behaviour, and why the same material has different absorption coefficients at different frequencies. I research these principles and write about them in accessible language — connecting the physics to the practical decisions that architects, engineers, studio designers, and anyone building or treating an acoustic space needs to make.
Why I Built This Site
Most RT60 calculators online give you a number. You enter room dimensions and materials, you get 0.8 seconds. But they do not tell you whether 0.8 seconds is good for your room’s purpose, what surface treatments would bring it into a better range, why the Sabine formula gave a different answer than the Eyring formula, or what happens to your RT60 when you add acoustic panels to only one wall.
Reverb-Calculator.com was built to give the number and the understanding that makes it actionable — to be the resource that connects the calculation to the acoustics physics, the design targets, and the practical treatment decisions that follow.
Accuracy Standards
Every page on this site meets the following standards before publication:
- RT60 calculation formulas are mathematically exact as published in the acoustic science literature
- Sabine constant values (0.161 for metric, 0.049 for imperial/feet) are correct and clearly stated
- Absorption coefficient data is sourced from published reference tables and attributed accurately
- RT60 target ranges are sourced from established acoustic standards and design guidelines including ISO 3382
- Where the Sabine and Eyring formulas give materially different results, both are documented with an explanation of which is more appropriate and why
- Limitations of the calculation models — including assumptions about room geometry, diffuse sound fields, and uniform absorption — are clearly disclosed
If you find an error anywhere on this site — a formula that does not verify, a coefficient value that contradicts a published source, a target range that is incorrect — please report it via the Contact page. All corrections are reviewed personally and applied promptly.
Tools and Content on This Site
- Reverb Calculator — the flagship tool: calculate RT60 using the Sabine equation from room volume, surface area, and average absorption coefficient
- How It Works — technical explanation of the Sabine and Eyring formulas and their application
- Reverb Calculator FAQ — common questions about RT60, room acoustics, and using the tools
- Educational articles on RT60 calculation, absorption coefficients, room design targets, and architectural acoustics
More tools will be added as the site grows.
Get in Touch
Contact: reverb-calculator.com/contact
How the tools work: reverb-calculator.com/how-it-works
Editorial standards: reverb-calculator.com/editorial-guidelines
Noah Bennett is the founder and sole author of Reverb-Calculator.com. All tool pages, educational content, and supporting pages on this site are written and maintained by Noah Bennett. Last updated: June 2026.