AcousticsCheck

B&L Lund AB

About this app

AcousticsCheck is a professional room acoustics measurement tool
developed by B&L Lund, AB Sweden — built for
acousticians, building engineers and facility managers who need
fast, reliable measurements in the field.

THREE MEASUREMENT METHODS

• ESS (Exponential Swept Sine) – Play an exponential sweep
through an external loudspeaker and let the server compute the
impulse response via deconvolution. Returns T20, clarity
(C50/C80) and STI per octave band (125 Hz–4 kHz).

• Interrupted Noise – Classic ISO 3382 method. Pink noise is
played and cut abruptly. The app records the decay and computes
T20 via Schroeder backward integration.

• Impact – Clap your hands or use a starter pistol. The app
captures the impulse response and analyses it on the server.

PROFESSIONAL MEASUREMENT ACCURACY

All measurements are analysed on B&L's server using the same
algorithms as professional acoustic software. You receive
band-resolved T20 with uncertainty estimates, signal-to-noise
ratio per band, and R² values for the decay line fit.
Measurements with high background noise are flagged
automatically.

MICROPHONE CALIBRATION

Connect a calibrated measurement microphone (USB or analogue
via an adapter) and upload your calibration file. The app
applies the frequency correction automatically to every
measurement so results are traceable to NIST/PTB standards.

SPEAKER PROFILING

Unsure about the frequency response of your measurement setup?
Hold the phone 5–10 cm from the driver and let the app build a
loudspeaker correction profile automatically. The profile is
stored locally and applied in real time during ESS analysis.

MEASUREMENT HISTORY AND COMPARISON

All measurements are saved locally with date, room details and
results. You can label rooms, add volumes and compare against
Swedish and Nordic standards (SS 25268, BBR, Boverket).
Recordings can be played back directly in the app.

QUOTE REQUEST

Select rooms that need treatment and send a combined request to
B&L Lund AB. Attach measurement data, room
information and photos directly from the app. Previous
requests are saved and can be supplemented with follow-up
measurements after treatment has been carried out.

REQUIREMENTS FOR ESS MEASUREMENT

• Wired external loudspeaker (Bluetooth introduces too much
latency)
• Calibrated measurement microphone recommended
• Internet connection for server analysis

Requires Android 8.0 or later.

What’s new

External USB microphones are now correctly detected across all platforms. Connecting a calibrated microphone automatically activates the matching profile.
Share calibration profiles between apps
Mic and speaker profiles can be exported and imported as JSON. Profiles from Bullerkollen open directly in Akustikkollen via the share sheet.
Stability improvements
Speaker calibration is only applied when the correct external speaker is connected.