Open Sound Meter1.5.2 - App Store

Open Sound Meter is an application for tuning and controlling audio systems in real-time.
Allows to measure and analyze:
- Spectrum
- SPL (RMS, Leq)
- Magnitude
- Phase
- Group delay
- Phase delay
- Coherence
- Impulse
- Step
- Spectrogram
- Impedance
- Nyquist plot
- Crest factor

You can store any result. Stored measurement can be adjusted by gain, delay and polarity, adjusted with filters, equalization.

Math function gives you a possibility to average your measurements, virtually join them and predict how they will sound together.

For better results, you can apply calibration files for your microphones.
For the measurement, you can use any iOS compatible audio interface or connect to your mixing console. Save the project on the device or in iCloud.

Direct connection works with Behringer X32, Midas M32, Allen&Heath Qu, DiGiCo S21/S31/SD12/UB-MADI, Yamaha TF and other consoles that have audio over USB. For Yamaha CL/QL you can use Dante AVIO adapter.

Version History New in 1.5
- Equalizer source
- Leq chart
- 200Hz Low-pass filter to measurements
- Gain, polarity and delay to filters
- Shelf, notch, band pass filters
- Q factor 4th order All-pass filter
- Deselect source by right mouse click
- Group and Equalizer properties available by click on the header of corresponding group
- Flat standard line
- Filter out mathematical noise in convolution

1.5.1 adds bug fixes and small corrections to the equaliser
1.5.2 improves delay finder and activates split view 1.5.2 09/17/2025 New in 1.5
- Equalizer source
- Leq chart
- 200Hz Low-pass filter to measurements
- Gain, polarity and delay to filters
- Shelf, notch, band pass filters
- Q factor 4th order All-pass filter
- Deselect source by right mouse click
- Group and Equalizer properties available by click on the header of corresponding group
- Flat standard line
- Filter out mathematical noise in convolution

1.5.1 adds bug fixes and small corrections to the eqalizer 1.5.1 09/04/2025 - Equalizer source
- Leq chart
- 200Hz Low-pass filter to measurements
- Gain, polarity and delay to filters
- Shelf, notch, band pass filters
- Q factor 4th order All-pass filter
- Deselect source by right mouse click
- Group and Equalizer properties available by click on the header of corresponding group
- Flat standard line
- Filter out mathematical noise in convolution 1.5 08/18/2025 - Groups
- Generator remote control
- SPL spectrum
- Phon spectrum
- Offset level
- Gain numeric
- LTW transforms for windowing from a time domain
- Frequency range for windowing from a frequency domain
- Points added into target trace
- Presets for target trace (default, immersive, car, headphones)
- Peak hold for numeric values
- Add Brown noise
- Add sin burst noise
- Support for csv calibration file format
- Export cal data with PPO and ignore data with bad coherence ( less 0.97 )
- Add 10 and 120 min Leq values
- Limits for linear impulse chart increased
- Enable Bluetooth and AirPlay devices
- Fix for iOS application as a server 1.4.1 01/16/2025 - Groups
- Generator remote control
- SPL spectrum
- Phon spectrum
- Offset level
- Gain numeric
- LTW transforms for windowing from a time domain
- Frequency range for windowing from a frequency domain
- Points added into target trace
- Presets for target trace (default, immersive, car, headphones)
- Peak hold for numeric values
- Add Brown noise
- Add sin burst noise
- Support for csv calibration file format
- Export cal data with PPO and ignore data with bad coherence ( less 0.97 )
- Add 10 and 120 min Leq values
- Limits for linear impulse chart increased
- Enable Bluetooth and AirPlay devices
- Fix for iOS application as a server 1.4 12/03/2024 fixes and improvements 1.3.2 02/25/2024 - Leq measurements
- Music noise replaced M-Noise (for updated AES-75 standard)
- Windowing source
- Exponential window function
- THD+N value measurement
- Input filters (A, C and 1 kHz Notch)
- Normalized impulse response
- Difference function in Math source
- Swipe gesture to hide but not delete the source
- Allpass filter added
- Peak filter added
- SNR calculated from squared coherence value
- Step chart limits extended
- RTA chart renamed to Spectrum
- SPL view renamed to Numeric 1.3 11/12/2023 MLS+ noise added. 1.2.3 03/14/2023 - Apply mode for math source
- Accurate tuning for weightings
- Option for inverse polarity for even channels in the generator
- Peak and Crest Factor values in digital meters
- System time in digital indicators
- Pause for Level charts
- Fixes and improvements 1.2.2 12/31/2022 - Added Butterworth filters
- Added Linkwitz Riley filters
- Added Bessel filters
- Filters could be used as any other data source
- Fixes and improvements 1.2.1 09/28/2022 - Added min and max functions for the math source
- Added resulting impulse response for vector math source
- Added level chart
- Added SPL/dbFs meters

Since v1.2 desktop versions could work remotely with iPad/iPhone applications 1.2 08/28/2022 - Impulse response time window is equal for frequency responses time window
- Add impulse response for math source in vector mode
- Add negative delay option
- Increase sweep sine period
- Add iPhone support
- Bug fixes and optimisations 1.1.4 07/11/2022 - Impulse response time window is equal for frequency responses time window
- Add impulse response for math source in vector mode
- Add negative delay option
- Increase sweep sine period
- Add iPhone support
- Bug fixes and optimisations 1.1.3 07/11/2022 - Added remote sources (via network)
- Added weighting curves (A, B and C)
- Added selection of many outputs in generator
- Added PPO option for line mode RTA
- Added FT windowing normalisation (for measurements with music as reference)
- Extended PPO ranges
- Extend Impulse and Step plots time limits
- Bug fixes and improvements 1.1.2 05/27/2022 - Added burst noise
- Added impedance mode for magnitude
- Added sample rate to stored notes
- Added inheritance of the settings when plot type changed
- Math source is allowed to select in a source in an other math source
- Force device's sample rate
- Extended frequency limits in plots (up to 96KHz) and generator (up to 192KHz)

Fixes:
- count for math source when cloned
- spectrogram auto add sources
- other minor issues 1.1.1 04/04/2022 - Add Bluetooth and multi-sample rate devices support with a selection of needed sample rate
Add experimental functions:
- Nyquist plot
- Crest factor plot
- Phase Delay plot
- Add Y-axis log scale for impulse response
- Add peak hold and crest factor
- Fix properties bar for min window size
- Add scroll to the side menu
- Show version in updater
- Add impulse data import from CSV
- Add export impulse to WAV
- Add auto names for stores
- Math source subtract method reworked
- Add linear mode to magnitude char
- Add missed FFT sizes
- Add units to impulse response properties
- Add invert option for linear magnitude graph
- Add SNR option for coherence chart
- Add selection to charts to show or hide the specific source
- Make charts source selection same width
- Add ignore coherence option to stored data

Also:
- Lots of improvements and fixes 1.1 02/14/2022 - M1 compatible
- internal loop buffer
- long delay finder
- dB and power modes for math source
- up to 10 sources to the math
- export stores to CSV files
- remake math for phase polar averaging
- fixed bugs and improve stability 1.0.9 12/09/2021 - Portrait orientation enabled
- Support slide view 1.0.7 09/15/2021 - improve UI
- spectrogram level normalization added 1.0.6 09/07/2021 - improve renderer
- bug fixes 1.0.4 08/12/2021 - Target trace added
- Phase chart positive values option added
- bug fixes 1.0.3 08/11/2021 iOS12 support 1.0.2 07/15/2021 UI improvements 1.0.1 07/04/2021 1.0 06/10/2021