SmaartTools for iOS single channel RTA is a full-featured audio spectrum analyzer based on the single-channel portion of Smaart 7 by Rational Acoustics.

If you need a two-channel FFT for your iOS device, check out Transfer Function, a module in our AudioTools app.

Smaart Tools was developed by Studio Six Digital in collaboration with Rational Acoustics and is based on the proprietary algorithms, techniques, features & color mapping found in the Smaart® v.7 acoustic test and measurement software.

Now, you can have the sophisticated analysis of Smaart® on the iPhone and iPod touch mobile platform.

The single-channel module includes the following features from Smaart® v.7: the RTA Bar graph, RTA Line graph, RTA Bar & FFT graph, and the Spectrograph. On the iPhone and iPod touch, there is an additional graph, the Spectrograph with the RTA Line graph on top of it.

All of the RTA banding options available in Smaart® v.7 are available, including log, lin, Octave, 1/3rd, 1/6th, 1/12th, 1/24th and 1/48th Octave modes.

The decay modes from Smaart® v.7 are also available, and include None, 1, 2, 4, 8, and 16 averages, and the Smaart 1-10 second custom decay settings, as well as Infinite, Fast, and Slow.

The frequency scale can be zoomed down to a single octave, and the dB scale can be zoomed down to 1dB resolution. Double-tap the screen to return to full frequency response, and to auto-scale the dB scale.

Real-time Spectrograph history is saved, just swipe to see sound events that have scrolled off the screen.

Other features include high-contrast mode, variable Spectrograph speed, vertical or horizontal running Spectrograph, Difference mode, Peak Tracking, and FFT Windowing.

All of the standard AudioTools features, such as Save / Recall and the Generator Panel are available. All settings are automatically saved and restored the next time that you run the app.

On iPad and larger iPhones, split graph mode is available, so that you can put any two graphs on the screen at the same time. Check out the screenshots to see if your device supports them.

Smaart Tools RTA Spectrum works great with the built-in iOS device microphone, as we have proprietary microphone compensation and calibration database derived for every iOS device. To upgrade to full professional results, use our iTestMic, or iAudioInterface2 with any test & measurement microphone.

Also see our other great audio test and measurement apps.

What’s New

Version 4.9

-Updated for iOS 13
-Fixed issue with setup menu
-Bug fixes and stability improvements

Ratings and Reviews

3.8 out of 5
4 Ratings

4 Ratings

soldoubt ,

I was wrong!!

App DOES support external interface!! Why no website or support though?! Crazy!!

Developer Response ,

Please see, and you can always contact us for support from the support page on that site. --Andrew

macphoto77 ,

Used it for years but needs updating

I have owned this app since it came out in 2010 or so. Best fft app available in my opinion. Last year I bought an iPhone X and have been disappointed ever since. Love the phone but for whatever reason this app does not like the new platform. It appears as a smaller screen in your bigger phone. Also I might add I now have an iPhone xs max and it has the same smaller screen format. Also some of the features/buttons are rounded off and sometimes not accessible until you flip your phone 180deg. Obvious the developer is not using this app on the new iPhone format ie no push button, extended screen and rounded corners. This app needs an overhaul.

Developer Response ,

First, thanks for being a long-time user and for reaching out to us. We appreciate the feedback, although we can respond quicker if you email us at
As to the app, we have tested and built for the new devices, including iPhone XS Max (I have one myself) and if you are running the latest version, 4.7.0, it should work well.
The "image in a box" is due to Apple adding the notch and the thin action bar at the bottom. We need to avoid those areas, and thus the app display auto-adjusts to avoid what Apple calls "safe areas'. We have rebuilt all of our apps to respect this screen area.
As to rounded-off buttons, if you could please send us more information about this to the email address above we would appreciate it.

soldoubt ,

Rip off!

Accidentally purchased this by an apparent fly-by-night app developer. I had purchased another app to analyze room acoustics from same developer and mistakenly purchased this. $50 for an app that cannot utilize an external interface!!! SMAART on the apple mic?!? What?!?

When I attempted to get a refund, I was blocked. Studio six's web site will not load a web page. I could not even google cache it to find contact info!!

This company has zero customer service, is a ghost. I highly recommend staying away from any of their software. Zero accountability, zero support, all profit for them. Total waste of money and I feel conned!!

Developer Response ,

I think you have your external interface working now, but if not, please contact us by our support page on --Andrew


Andrew Smith
29.8 MB

Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, French, German, Japanese, Polish, Simplified Chinese, Swedish

Age Rating
Rated 4+
© Andrew Smith
In-App Purchases
  1. Reference Curves Option $14.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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