SPLnFFT Noise Meter 4+

Serious audio measurements

Fabien Lefebvre

    • 4.9 • 40 Ratings
    • $3.99
    • Offers In-App Purchases



Serious audio measurements since 2010

SPLnFFT is a sound level meter (noise meter) for your iPhone or iPad with many advanced features: frequency analyzer, frequency meter, test signal generator, dosimeter, ...

This soundmeter App is the only one for iOS recommended by the "Laborers' Health and Safety Fund of North America".
Here are extracts from other reviews:
"our favorite sound measurement app" SafetyAwakenings.com
"SPLnFFT is comprehensive, easy to use" TapeOp.com
You will find more reviews here: https://www.facebook.com/SPLnFFT

For daily use, a very simple interface displays the level of exposure: if orange or red, protect your ears !
Professional users will take advantage of a wide range of accurate and reliable measurements: Leq, peak, L10, L95, taktmaximal, frequency analysis, histogram, dosemetering, ... A&C weightings are compliant with ANSI® S1.42 standard. "468" refers to ITU-R 468-4

>>> Some KEY INFORMATION <<< :
- you absolutely need to allow access to microphone to use this App
- screen rotation must be un-locked
- there are built-in help messages (speech bubble). Need more ? Contact us !: email, blog, Facebook,...
- do not expect to measure as low as 0dB(A) in a quiet room, for these 2 reasons: 30-130dB(A) is the standard usable range for sound level meters and anyway a standard quiet room is around 30dB(A) whereas a typical anechoic chamber is 10 to 20dB(A)
- to change frequency weightings (dB(A),dB(C),...) a LONG PRESS is required (1/3rd of a second). This is to avoid accidental changes

Top digital display is for measurement of sound power in 'slow' mode (averaged on 1s). Central analog display is for 'fast' mode (averaged on 1/8th s). But it can display 'slow' mode as well on request: just click on 'fast' label.
Peak and average values are displayed below and are held until you touch the 'reset' label. The videos on Youtube reveal more details.

Bottom view is a real time FFT (frequency analysis). You will notice that predominant frequency and next one are highlighted. Their frequencies and relative power are displayed on the right. If your input signal is a pure tone then this App will lock on its frequency and display a very accurate result.
Green line is the result of a real time FFT done with 1024 points. Purple line is the averaged FFT (exponential filtering done on power of each frequency). Blue line is a copy of what the purple line was when the user froze the display the last time.
A test tone at 1kHz or a white noise or a pink noise can be generated and sent to right and/or left outputs (select the type you want in BEEP tab). This FFT view - more precisely an upsized version of it - can be exported as a picture in your own photo library, using the camera button (when display is frozen only). This picture can be exported in a mail as well.
The display can be flipped upside-down to ease reading: just rotate your iPhone while holding it vertically.

As for ALL sound meters (thus including this one and all others at any price), calibration is suggested if you want to reach extreme precision. This is enabled in this App thanks to a slider to apply some compensation and to three non volatile memories (choice to be made in MIC. tab). How to ? For calibration, you need and external reference, either a calibrated sound meter, or a calibrated noise source.
Note as well that the tiny embedded loudspeaker cannot reproduce extreme frequencies. Thus if you want to hear a real white or pink noise, you will need to use a quality headphone or HiFi system.

This App was designed seriously for our own needs, by a signal processing expert, and is regularly updated to maintain accuracy and reliability.

***** Any comment, any feedback ? Click on 'support' in iTunes: there is a blog for this. You can even contact us directly by email or through the dedicated FaceBook page (note 'send email' top right) *****

What’s New

Version 7.0

Optimized for latest iPhones and iOS.
Note that iPhone X and later do NOT support any more upside down orientation.

Ratings and Reviews

4.9 out of 5
40 Ratings

40 Ratings

DavidRuess ,

Fantastic, Reliable, Useful

I use this app several times a year and have used it for many years. It is a fantastic reliable and useful app. I highly recommend it.

It’s very helpful when measuring speakers, general levels of noise if I’m in an audience, and I even use it with over the ear headphones (I just get the mic-end of the phone as close I can where my ears would reside within the earpiece to get a general idea so I protect my ears).

If you don’t have a dedicated spl meter (or don’t carry one around with you) I recommend you get this. You won’t be disappointed. 🙂

Eivind T ,

My best app purchase

I use it all the time to understand more about the audio environment around me.

I bought it several years ago. The author has all the time kept the app updated and current. Seems to be someone who cares deeply and really knows the domain.

RCRX1800 ,

Very Accurate

I’ve used this app for several years, it’s extremely accurate. I use it mainly for live music inside a club venue. This app stays reliable and steady along with upgrades of phones.
I’ve found zero inconsistencies.
It does help me show guitar players that their stage amp is louder than the PA.

App Privacy

The developer, Fabien Lefebvre, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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