Sonaroom Beta

Public beta 0.1.0

Reads Sonasync measurements →

Sonaroom3D Acoustic Simulator

Model the room.
Hear the treatment.
Check it against
the measurement.

Sonaroom builds the room in 3D, predicts how long it rings in every octave band, and lets you put real acoustic panels on its walls and ceiling the way you would in SketchUp. It plays you the room before and after, and when Sonasync has measured the real room, it reads that measurement beside the prediction — so the treatment is bought on numbers, not on a brochure.

Download the beta Reserve a licence How it calculates

Windows 10/11 64-bit · Linux soon · free during the beta · no account, no telephone home

What it does

Ten things, in the order a room job goes

Draw the room. Say what it is made of. Put the source and the listener where they really are. Predict, treat, listen, and print it for the client. Every step shows its number before you move on, and every number can be traced to a formula on this page.

  1. 1Room

    A shoebox by its three dimensions, or any floor plan drawn point by point with its own height. Volume and surface areas are worked out from the real shape, not its bounding box.

  2. 2Materials

    Absorption per octave band for every surface, from a library you can edit. Porous absorbers can be designed from thickness and density, with a third-octave curve, NRC and SAA.

  3. 3Treatment

    Real panels, bass traps and diffusers from a product library. Place them by hand: the panel follows the mouse and snaps onto the wall or ceiling it is over, like SketchUp, with undo for every move.

  4. 4Air

    Temperature and humidity of the room. At 8 kHz the air in a big hall absorbs more than many walls do, and the prediction knows it.

  5. 5Reverberation

    Sabine and Eyring RT60 for every octave band, before and after treatment, side by side.

  6. 6Impulse response

    Image sources for the early reflections and a matched diffuse tail — or a full ray trace for any shape. Read the way a measurement is read: EDT, T20, T30, C80, D50.

  7. 7Listener and level

    Where the listener sits, and a map of sound pressure level over the whole room: direct sound plus the room’s reverberant field.

  8. 8Room modes

    The axial, tangential and oblique modes, and the Schroeder frequency below which modes — not reverberation — shape the bass.

  9. 9Listen

    Your own music or speech through the room, untreated and treated, switched in one click. Both exported as WAV for the client to hear.

  10. 10Report

    A PDF, and a single HTML file with every plot and a cursor that reads values as you move along the curve — the way Sonasync’s report does — with the before and after audio inside it.

With Sonasync

Sonasync fixes the system. This fixes the room.

An equaliser can flatten a loudspeaker. It cannot shorten a reverberation: a long decay is the room giving the sound back late, and no filter in the rack takes energy out of the air after it has left the box. Sonasync already tells you which part of a response EQ can fix and which it cannot. Sonaroom is where the part it cannot fix gets fixed — and the two read the same measurement, with the same analyser, in the same units.

  1. SonasyncMeasure the room

    Swept sine through the PA, from the seats that matter. Each sweep’s whole decay is kept, not just the part an EQ needs.

  2. SonasyncExport the impulse

    A mono 32-bit float WAV with a .json beside it, written straight into a shared folder: Sonasync measurements / RoomAcoustic 3D.

  3. SonaroomImport it

    One button, Import room impulse from Sonasync, opens that folder. It is found by itself — read from Sonasync’s own settings.

  4. SonaroomCompare and treat

    The measured T30 is drawn on top of the predicted Eyring curve. Match the model to the real room, then design the treatment on a model you trust.

  5. SonasyncMeasure again

    After the panels are up, measure again and import again. The report shows prediction and measurement on one plot.

Read the way ISO 3382 reads it

  • EDT, T20 and T30 per octave band, each with the r² of its straight-line fit — below about 0.98 the number is not one to quote, and the program says so.
  • C50, C80 and D50: clarity for speech and for music, and definition.
  • The noise floor is measured from the tail and the Schroeder integral is cut where the decay meets it, so noise is never read as reverberation.
  • A band whose decay never falls far enough says so — T30 needs 45 dB of clean decay, T20 35, EDT 20 — rather than inventing a number.
  • The band filter is the same zero-phase filter the Sonasync analyser uses, so a T30 here and a T30 there are the same T30.

No copying files about

Sonasync keeps its measurements folder in its own settings. Sonaroom reads that setting, finds the RoomAcoustic 3D folder inside it, and opens there. If Sonasync has never been told where to keep its measurements, both programs fall back to Documents/Sonasync/measurements — the same place, by the same rule, written down once in each program.

A measurement belongs to a real room, not to a project, so it stays loaded when you open another project: measure once, try three designs against it.

The impulse the simulator makes is checked the other way round, too: read back through the same analyser that reads Sonasync’s files, its T30 lands within 10 % of the Eyring prediction in every band. The analyser is tested on the prediction before it is trusted with your room.

The science

Where every number comes from

Nothing here is a black box. These are the formulas the program actually runs — each one published, most of them older than the people using them — and the standards that say how to apply them. Where a simple formula stops being right, the program uses a better model, and says which one it used.

Sabine and Eyring, with the air

The two classic reverberation formulas, per octave band, with the air’s own absorption added as the term 4mV.

Sabine T = 0.161 V / (A + 4mV) Eyring T = 0.161 V / (−S·ln(1 − ā) + 4mV) A = Σ Sᵢαᵢ ā = A / S α ≤ 0.99

Sabine (1922), Eyring (1930). Eyring holds where Sabine over-reads a well-treated room; both are shown, so you see how far apart they are.

Air absorption, ISO 9613-1

The pure-tone attenuation of air at the room’s temperature, humidity and pressure, converted to the energy coefficient the room formulas use.

m = αair / (10·lg e) [1/m] energy falls as e^(−m·r)

ISO 9613-1:1993, applied the ISO 354 way. Checked against the standard’s own table to within 3 %.

Image sources, then a diffuse tail

Every mirror image of the source up to the chosen order, each losing √(1−α) of its pressure at every wall it bounces off, in every band. Where the image set stops being complete, a diffuse tail takes over at exactly the energy the images would have added up to — so the two parts join without a step.

image p = (1/r)·Π √(1 − αᵢ)·e^(−m·r/2) tail dE/dt = 4πc / V · e^(−13.8·t / T)

Allen & Berkley (1979). The tail’s noise is seeded: the same room gives the same impulse response every run.

Ray tracing, for any shape

Rays from the source into the 3D mesh, each hit found with the Möller–Trumbore triangle test, energy collected at the listener in a histogram per band, and turned into a real pressure impulse through octave filters. How long and how far it traces is worked out from the room itself.

window 1.5 × the longest predicted RT60 bounces from the mean free path 4V / S stop a ray 70 dB down is dropped

Krokstad, Strøm & Sørsdal (1968); Möller & Trumbore (1997). Order-8 Butterworth band filters, causal, so nothing arrives before the direct sound.

Level over the room, Barron’s revised theory

Direct sound plus the reverberant field — which falls slowly with distance, because sound reaching a far seat has been decaying for longer.

Lp = Lw + 10·lg( Q/(4πr²)·e^(−m·r) + (4/A)·e^(−0.04·r / T) ) A = 0.161 V / T

Barron & Lee (1988). Its reverberant level is checked against a sum over image sources.

Reading a decay, ISO 3382-1

The same reading for a simulation and for a measurement. Time zero is the direct sound — the first sample within 20 dB of the peak — not the moment the source fired.

Schroeder E(t) = ∫t∞ p²(τ) dτ EDT 0 to −10 dB × 6 T20 −5 to −25 × 3 T30 −5 to −35 dB × 2 C80 = 10·lg( E0–80 ms / E80 ms–∞ )

Schroeder (1965); ISO 3382-1, annex A.3.4 for the onset.

Room modes and the Schroeder frequency

Below a certain frequency a room stops behaving like a reverberant space and behaves like a set of resonances. The program lists them and marks where that change happens.

f = (c/2)·√( (nx/L)² + (ny/W)² + (nz/H)² ) fS = 2000·√( T / V )

Rayleigh’s room modes; Schroeder’s transition frequency. Why it matters in small rooms: Toole (2006).

Materials, from physics

A porous absorber designed from its thickness, density and air gap, on the 32 third-octave bands of ISO 266; walls by the mass law. NRC and SAA computed the way the ratings are defined.

porous Miki’s model (improved Delany–Bazley) walls mass-law transmission loss ratings NRC; SAA per ASTM C423 (200 Hz–2.5 kHz)

Miki (1990). Product data in the library is the manufacturer’s own.

  • ISO 3382-1 room acoustic parameters
  • ISO 9613-1 absorption by air
  • ISO 354 the 4mV convention
  • ISO 266 preferred frequencies
  • ASTM C423 SAA

How it is checked

A formula is only as good as the test that holds it to the answer

“Accurate” is a claim. These are the checks behind it — 100 automated tests in 36 files, every one run on Windows and on Linux before a build is allowed out. Each holds a part of the program to an answer worked out another way: a published table, a closed-form decay, or a second model.

What the tests hold the program to
WhatAgrees toChecked against
Air absorptionwithin 3 %The ISO 9613-1 table, at several temperatures and humidities
Image-source impulse, read by the measurement analyserT30 within 10 %Eyring, in every octave band
Ray tracer in a live roomwithin 10 %Eyring, in every octave band
Ray tracer’s pressure impulseT30 10 % · C80 1 dBThe energy its own rays carried
A known decay, read backT20, T30 within 10 % · r² > 0.98The decay it was made from
Clarity and definitionC80 0.3 dB · D50 0.02An exact exponential decay
Noise in a measurementnever read as reverberationA decay buried in noise on purpose
Barron’s reverberant levelmatchesA sum over image sources
Direct soundexactThe inverse-square law

The packaged program checks itself too: every release build starts the finished program, runs the acoustics, the ray tracer, both reports and the audio, and is not packaged unless all of it passes.

Research

Built on published work, the AES’s first

The methods here were not invented for this program. They come from the Journal of the Audio Engineering Society, its conventions, and the acoustics literature it rests on. Each entry says where it shows up in the program.

  1. AES
    Kleiner, M., Dalenbäck, B.-I. & Svensson, P. — “Auralization — An Overview” J. Audio Eng. Soc. 41(11), 861–875, 1993

    In the program: the listening stage. A room’s impulse response, convolved with dry material, lets you hear a room that is not built yet — and hear it again with the treatment in.

  2. AES
    Farina, A. — “Simultaneous Measurement of Impulse Response and Distortion with a Swept-Sine Technique” AES 108th Convention, Paris, preprint 5093, 2000

    In the program: where the measured room comes from. Sonasync measures with swept sines, and the long impulse it exports is what Sonaroom reads.

  3. AES
    Toole, F. E. — “Loudspeakers and Rooms for Sound Reproduction — A Scientific Review” J. Audio Eng. Soc. 54(6), 451–476, 2006

    In the program: the room-modes view and the Schroeder frequency. Below it, a small room is a set of resonances, and treatment has to be judged there differently from above it.

  4. AES
    Savioja, L., Huopaniemi, J., Lokki, T. & Väänänen, R. — “Creating Interactive Virtual Acoustic Environments” J. Audio Eng. Soc. 47(9), 675–705, 1999

    In the program: the shape of the impulse response — exact early reflections from image sources, joined to a statistical late reverberation.

  5. JASA
    Allen, J. B. & Berkley, D. A. — “Image method for efficiently simulating small-room acoustics” J. Acoust. Soc. Am. 65(4), 943–950, 1979

    In the program: the image-source engine, wall by wall and band by band.

  6. JSV
    Krokstad, A., Strøm, S. & Sørsdal, S. — “Calculating the acoustical room response by the use of a ray tracing technique” J. Sound Vib. 8(1), 118–125, 1968

    In the program: the ray tracer, for rooms that are not boxes.

  7. JASA
    Vorländer, M. — “Simulation of the transient and steady-state sound propagation in rooms using a new combined ray-tracing/image-source algorithm” J. Acoust. Soc. Am. 86(1), 172–178, 1989

    In the program: why there are two engines, and why each is checked against the other and against Eyring.

  8. JASA
    Schroeder, M. R. — “New method of measuring reverberation time” J. Acoust. Soc. Am. 37, 409–412, 1965

    In the program: every decay curve, measured or simulated, is a Schroeder backward integral.

  9. JASA
    Barron, M. & Lee, L.-J. — “Energy relations in concert auditoriums. I” J. Acoust. Soc. Am. 84(2), 618–628, 1988

    In the program: the level map over the room.

  10. JASA
    Eyring, C. F. — “Reverberation time in ‘dead’ rooms” J. Acoust. Soc. Am. 1, 217–241, 1930

    In the program: the RT60 the other models are held to.

  11. Book
    Sabine, W. C. — Collected Papers on Acoustics Harvard University Press, 1922

    In the program: the Sabine RT60, and the optimiser’s quick estimate.

  12. JGT
    Möller, T. & Trumbore, B. — “Fast, minimum storage ray-triangle intersection” Journal of Graphics Tools 2(1), 21–28, 1997

    In the program: every ray hit in the ray tracer.

  13. ASJ
    Miki, Y. — “Acoustical properties of porous materials — Modifications of Delany–Bazley models” J. Acoust. Soc. Jpn. (E) 11(1), 19–24, 1990

    In the program: the absorber designer in the material editor.

Where this stands

A beta, and what that means here

Everything on this page works and is tested. What follows is what it does not do yet, so nobody finds out on a job.

  • Image sources are for box-shaped rooms. A drawn floor plan is simulated by the ray tracer instead, which handles any shape.
  • Room modes of a drawn plan are those of its bounding box — a rough guide, and labelled as one.
  • No diffraction. Sound bends round edges in a real room; geometric models, this one included, do not follow it. It matters most at low frequencies and around small objects.
  • Absorption is only as good as its data. Product figures are the manufacturers’ own; the library has five products to start and takes your own.
  • Panel placement is phase one: place by hand, snap to the surface, move, undo. Dragging an existing panel, arrow-key nudging, typed distances and panel arrays come next.
  • Not code-signed. Windows SmartScreen shows a “Windows protected your PC” notice the first time. Choose More info → Run anyway.

Pricing

Free while it is in beta. Reserve your licence now.

During the beta the whole program is free to use, with nothing locked. Prices are set before the full release. Reserve a licence today — nothing to pay, nothing to sign — and you are offered it first, at a founder’s price, before anyone else can buy.

Now

Beta

Free during the beta

Everything, for anyone who wants to try it

  • The whole program, unlocked
  • Sabine, Eyring, image sources and ray tracing
  • Treatment with real products, placed by hand
  • Sonasync measurement import
  • Before / after auralization and WAV export
  • PDF and HTML reports
  • Windows and Linux
Download the beta

At release

Pro

Price reservedannounced to reservation holders first

The full program, for paid work

  • Everything in the beta
  • Every update of the version you buy
  • Bought once, yours permanently — no subscription
  • Founder’s price for everyone who reserves before release
Reserve Pro

At release

Pro + Sonasync

Price reservedfor less than the two bought apart

Measure the room, then fix it

  • Sonaroom
  • Sonasync Suite — Time Align and Correction
  • The round trip: measure, import, treat, measure again
  • Already own Sonasync? Say so when you reserve.
Reserve the bundle

How reserving works

Email masterpro0115@gmail.com with the name the licence should be issued to — yours, or your company’s — and which edition you want. That is the whole reservation. You pay nothing now, and you can change your mind at any time.

Before the full release, every reservation holder is sent the price and the founder’s price, before they are published here. Buy then, or don’t.

When sales open, payment is by PayPal internationally and GCash within the Philippines, and licences are issued by hand, by a person, usually within a day — the same way as Sonasync.

Download

Get the beta

Version 0.1.0. Every build here passed the full test suite and its own self-test before it was packaged.

Download from the releases page
  • Windows installer Sonaroom-0.1.0-windows-x64-setup.exe · 133 MB
  • Windows, no install Sonaroom-0.1.0-windows-x64.zip · 207 MB

Windows 10 or 11, 64-bit. The installer needs no administrator rights.
Linux packages (.deb, .rpm, .tar.gz) follow in a later beta.
This program is not code-signed: on first run choose More info → Run anyway.