Back in the old days, measurements required an array of bulky black boxes. Scopes, tone generators, and calibration devices usually took up at least several square feet of surface on every tech’s desk. Then along came the computer age, and all those boxes were compressed into one medium-sized case with a portable computer, external interfaces, calibration microphones, and all the necessary cables. I was amazed when Kevin Voecks came over to my home to set up a Revel speaker system and I saw such a rig for the first time. Out of a slim briefcase he produced everything he needed to run a complete battery of tests on my room. The whole process took him less than half an hour.
In this age of iPads and iPods it had to happen—someone has developed a complete suite of audio tests for the iPad, iPod, and iPhone called “AudioTools.” The basic AudioTools app package costs $19.99. It comes with four of its twenty-four modules enabled. These active modules include an SPL meter, real-time analyzer (RTA), signal generator, and recorder.
The AudioTools SPL meter looks very much like a classic RadioShack analog SPL meter. Anyone who’s used an RS unit will be quite familiar with its layout and functions, as they are identical to the original device. With AudioTools’ real-time analyzer and signal generator you can examine the frequency response of your speakers in any room or test environment. Finally the recorder functions let you use your iPod, iPad, or iPhone as a portable recorder with selectable sample rates from 8kHz to 48kHz.
The start-up menu for AudioTools has six test categories—SPL, Acoustics, Line Input, Speakers, Utilities, and Settings. Under SPL tests you’ll find the analog SPL meter, an SPL Pro meter, an SPL graph, and something called Traffic Light. This last test lets you set sound-pressure-level trigger points so you get a visual representation of the SPL levels—green is for acceptable limits, yellow for when the level approaches a pre-set point, and red for when that pre-set level is surpassed for a specific duration of time. This test is ideal when you need to know quickly whether an SPL level exceeds a pre-established limit.
Acoustic tests include an RTA, FFT (Fast Fourier Transform), ETC (energy time curve), Impulse Response test, and Smaart Tools 1 test suite. Smaart Tools was developed by Studio Six Digital in collaboration with Rational Acoustics and is based on its proprietary algorithms, techniques, features, and color mapping. Line-input tools feature a signal generator, audio scope, VU meter, and THD+N (total harmonic distortion plus noise) and amplitude-sweep generators. Under the Speaker Tests menu you’ll find tests for polarity, distortion, impedance, an impedance sweep, and a delay finder. The utilities section contains a signal generator, monitor, calculator, recorder, and data and audio file export functions. Under settings are the global, microphone, line-input, and line-output adjustments.
All except the nine base-level apps in AudioTools are available for purchase on an à la carte basis. The prices range from as little as $7.99 for a more sophisticated SPL meter to $59.99 for the Room Impulse Response test. If you are contemplating buying any of these additional apps, you can access Studio Six Digital’s YouTube tutorial videos about the app’s functions. Each and every à la carte app has its own YouTube tutorial. These videos walk you through all of an app’s functions, how to use it, and how to set it up properly. I wish all iPod/iPad programs had this level of instructional ergonomics built in.
By default AudioTools utilizes the iPod/iPad/iPhone’s built-in microphone, but you can also employ an external instrument/calibration-grade microphone through Studio Six’s auxiliary iAudioInterface module. This $229 device works with all first-, second-, and third-generation iPod Touches. It enables high-quality line-level analog-audio inputs and outputs for all the AudioTools tests. Unfortunately the iAudioInterface does not work with the latest fourth-generation devices because Apple changed the I/O so the earlier pin-outs are no longer compatible. Studio Six Digital is in the final stages of developing a new interface device for the fourth generation, and it should be available by early summer. Studio Six Digital even offers an upgrade program so owners of the first-generation iAudio Interface boxes can receive 50% of their original purchase price to apply to the new unit.
I’ve been using AudioTools’ base set of tests since before CES. At the big show the SPL level meter proved to be invaluable—I finally had an accurate and convenient way to make sure that I was listening to music at the same SPL level from room to room. I could also tell when a room was playing music too loudly, which I discovered was the norm at CES. Obviously this is probably the most simple-minded (but still practical) use for AudioTools. More ambitious applications include measuring your speakers’ actual vs. published “nominal” impedances, and discovering how your speakers are interacting with your room.
If you’ve had a desire to test, tweak, optimize, or even build your own music system from scratch, the tests included in the AudioTools app will make your job easier than before. All this ergonomic elegance can be had at a price that makes most stand-alone test gear almost completely obsolete. If ever you needed another reason to buy an iPod, iPad, or iPhone, the AudioTools Suite is a pretty darned good one.
SPECS & PRICING
AudioTools iPad/iPod/iPhone App
Type: Software for the iPod Touch, iPad, and iPhone
Price: $19.99 for base module, other test modules available for download from $7.99 to $59.99
STUDIO SIX DIGITAL
5050 Pierre St Unit D
Boulder, CO 80304