StudioSix Digital Does Serious DIY Audio Measurement on the iPhone
While wandering the aisles of the recent Audio Engineering Society show in San Francisco, I found a great little measurement rig for the iPhone, iPad, and iPod touch that deserved inclusion in my recent article on DIY audio measurement in the January 2011 issue of S+V [on stands now]. Unfortunately, the article had already gone to press, so I thought I'd report on the system here.
Most of the audio spectrum analysis software for iPhones, Droids, etc., is fine for quick'n'dirty tests but lacks the necessary resolution for the serious measurements discussed in the article. The products from StudioSix Digital are much more suitable for the lab-coat crowd-even if your lab coat's getting a little threadbare.
The company offers a measurement app called AudioTools, which includes many basic functions, and you can upgrade it with additional modules. It also sells a dedicated audio interface called the iAudioInterface that includes a calibrated measurement microphone.
The real-time spectrum analyzer included in the basic version of AudioTools offers maximum resolution of 1/3-octave, which isn't adequate for serious measurements. However, the optional FFT module offers much better resolution. While its finite resolution limit is 1/120-octave, you'd probably use it in 1/24-octave smoothing mode, which gives it all the resolving power you need to get your subwoofer(s) tweaked to perfection.
AudioTools costs $19.99, and the FFT module costs an additional $19.99. If you have an iPhone, you really don't need anything more - the software's calibrated for the internal iPhone mic, and for basic in-room measurements that should be adequately accurate. If you have an iPod touch or you want lab-quality accuracy, you can add the iAudioInterface for $229.99. Although I was able to get only a 15-minute run-through at AES, the StudioSix Digital products seem like a powerful yet reasonably priced alternative to dedicated audio measurement hardware.