SMAART (short for Sound Measurement Acoustical Analysis Real Time) was the first dual-channel measurement platform made to work with non-proprietary computer and audio I/O hardware, effectively bringing these tools to the masses. Last year, Rational Acoustics released SMAART version 7 (new license, $895; upgrades $450-$650), which is more efficient than predecessors and was built using object-oriented code architecture (meaning that the data gathering engines and display functions, for example, are now treated as separate modules). This allows for a tremendous increase in flexibility for setting up multichannel measurements; computer hardware is now the only factor limiting the number of measurements that can be run simultaneously.
Unlike traditional RTAs (Real- Time Analyzer), SMAART can display multiple input sources on one screen, with a different colored line representing each source. SMAART 7 is capable of displaying real-time averages derived from multiple input sources on the RTA display, which was not possible in previous versions. Also part of SMAART’s spectral engine, the Spectrograph display shows RTA information over time. In this plot, frequency remains on the x-axis, but the y-axis is replaced by time, and SPL is indicated by color. This is a useful tool for viewing the spectral content of dynamic music, or identifying problem frequencies (in lavaliere microphones, for example).
The real power of SMAART, however, lies in the transfer function measurement mode, used for measuring changes that occur from one point in the signal chain to another. In the live sound context, one common practice is to use SMAART to compare the signal leaving the mixing console against a measurement microphone. This allows the system engineer to see the cumulative effect that the system processor, loudspeakers and acoustic space have on the response.
Because the transfer function measurement is the result of comparing two signals, the source material does not matter, provided that all of the frequencies of interest are present. This is extremely powerful in that it allows full bandwidth music to be used in place of pink noise for optimizing sound systems. It additionally allows system engineers to compensate for changes to the acoustical characteristics of a space (i.e., a venue filling up with people) in real time, using whatever program material is running through the PA. Also integral to the Transfer Function screen is the phase trace, which is critical for setting driver alignment delay and crossover parameters.
A new feature of SMAART 7 is the ability to display averages from multiple (transfer function) measurement groups. One obvious application would be to take the information from several different measurement microphones placed at different positions throughout the space, and display their average as a single line (delay compensated and real-time averaged).
Unlike the Spectral and Transfer Function measurements, the Impulse Response (IR) measurement mode is a time-domain measurement, displaying sound energy over time. IR measurements are useful in acoustical analysis, allowing for the visualization of reflections and signal-decay characteristics.
I have had the opportunity to employ SMAART on tours, one-off concerts and corporate events, and in the alignment/commissioning of permanently installed systems. SMAART 7 is an indispensible tool. It is very stable and includes a number of UI improvements over previous versions. The company recently released an API (application programming interface), which will pave the way for seamless real-time interaction between SMAART and other software programs. The folks at Rational Acoustics plan to continue adding both new functionally, all of the features that were present in version 5 and all of the functionality of SMAART acoustic tools (an IR-based companion program to SMAART 5 with extended capabilities) as part of the standard software package, including the ability to produce a waterfall plot from IR data. Rational Acoustics is clearly in it for the long haul. SMAART 7 is a fantastic program, and the training and support are superb.