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Free Apple iOS acoustic measurement app created by Studio Six Digital for JL Audio

Studio Six Digital, makers of the AudioTools acoustic measurement software for Apple iOS, have created a free acoustic measurement app for JL Audio called, rather creatively, “JL Audio Tools”. iOS is the operating system used by Apple’s iTouch, iPhone and iPad devices and hence this free app will run on any of them. Obviously the iTouch and iPad will need some kind of microphone attached since they do not come with this as standard. The app can be downloaded directly from the iTunes store. More information on the app can also be found at the app page on the main Apple website.

In this blog post I’m going to walk you through the main features of the app. Once you’ve downloaded the app and launched it the first screen you see is the menu screen. The JL Audio Tools app does not have all the features of the paid-for Studio Six Digital Audio Tools app but does have many of them. The JL Audio app offers a Sound Pressure Level (SPL) meter, a Real Time Analyzer (RTA), a speaker polarity test and some handy audio calculators.


The first feature is the SPL meter, which is a basic offering that does not include any choice of weighting curves (and I’m not exactly sure what weighting it is set to as standard although I would imagine it is a C weighting) or additional features such peak hold.

The next feature is a RTA which is displayed on the iOS device in landscape. The RTA has a switchable octave or one third octave control and runs from 20Hz to 20kHz. Personally I think this is one of the best features in the whole app although again it doesn’t offer control over decay speed or offer a peak hold function.


The next features are the set of audio calculators. There is an ohm’s law calculator, an amplifier power calculator, a dB conversion calculator and my personal favorite, the sine wave calculator.

The sine wave calculator is really useful, since you can quickly enter any of frequency, wavelength and time and it recalculates the other values. I often use a calculator like this when evaluating the acoustics of someone’s room. The calculator is useful since it enables you to identify where nulls for particular room modes might be (at the quarter wavelength position).

The final feature is a speaker polarity test function. To get this to work you need to download a wave file from the Studio Six Digital website and burn it to a CD or other device to generate the test signal. In my opinion this is a great feature, since you can pay upwards of $100 for a standalone hardware polarity test set which doesn’t fit in your pocket! Quite a few times I have found a speaker incorrectly wired in a home theater setup due an installers misunderstanding of how to wire adjacent bipole speakers. I even came across it once in a high end audio setup where the owner wondered why there was no central image!

Overall this is a great set of acoustic measurement tools for a great price – free! Acoustic Frontiers is proud to be a JL Audio dealer for the F110, F112 and F113. We offer free in home installation and subwoofer calibration for both high end audio setups where the subs support a pair of speakers and for home theater environments. Our subwoofer calibration process must be one of the best in the business – we use high resolution acoustic measurements to perfectly set crossover points, phase and delays. The result is seamless integration from sub to speakers. We also offer the subwoofer calibration process separately. It normally takes about a half day to set up a pair of subs. If you are interested we’d love you to get in touch.

4 thoughts on “Free Apple iOS acoustic measurement app created by Studio Six Digital for JL Audio”

  1. Nice to hear about this free version of Audio Tools, i've owned the pay version for some time and find it very useful. Recently on my iPhone however I've noticed an almost 4 db discrepancy between Audio Tools SPL's and other iPhone SPL apps, and my Radio Shack meter (admittedly not the ultimate reference but at least it's external to the iPhone / iPad). The other apps allow you to calibrate the input to a known reference (in my case the Shack meter – everything C weighted). Can you calibrate the Audio Tools products? (haven't found it) How about this free one?

    Correction on the iPad, Audio Tools works great as they have built in mics, the RTA display is especially nice on the larger screen (as well as a cool 'old fashion' looking SPL meter). Also my iPad2's SPL pretty much agrees with the Radio Shack.

    Thanks for the review and pointing out this free app – Bruce

  2. Hi Bruce

    Thanks for the comments! I just looked and yes you can change the mic calibration in the setup for the JL Audio app. You just enter a value in the box called 'Mic Calibration' and it adjusts the SPL outputs.


    1. Thanks for the comments! I just looked and yes you can change the mic calibration in the setup for the JL Audio app

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