Smaart® Control
Smaart Control enables loudspeaker measurements in Rational Acoustics’ Smaart software to be controlled by FIR Designer, captured in real-time & seamlessly integrated into the FIR Designer workflow for use in filter & DSP design. (Pre-existing Smaart files can still be manually imported into FIR Designer.)
Smaart Control is particularly helpful in time-limited live sound applications, enabling fast measurement capture and creation of custom DSP for system optimization.
Smaart Control includes support for the “moving mic measurement” method, which is often used as an efficient way to take a spatially averaged measurement with a single microphone, rather than averaging the response of multiple microphones at fixed positions.
Don’t use Smaart? No problem – FIR Designer can import data from other audio measurement tools
Using Smaart Control
Open Smaart Control from the Import tab
With Smaart open locally or on any networked computer, FIR Designer’s Smaart Control dialog (accessed from the Import tab) can live-stream any available Smaart Spectrum or Transfer Function measurement. Smaart’s signal generator on/off and measurement magnitude & phase banding or smoothing can all be controlled remotely.
A snapshot of a measurement can be taken from Smaart’s live measurement stream and stored locally in a ‘grabbed’ measurement list. Any measurement in the list can be sent via a single click to one of three destinations: the ‘Import’, ‘Target’ or ‘Averaging’ tabs, for use in the DSP design workflow.
Smaart Control is available in FIR Designer, FIR Designer M and FIR Creator EX. (Note that in FIR Creator EX, data can be sent only to the Import & Target tabs, as FIR Creator doesn’t include built-in measurement averaging.)
Smaart® Control in FIR Designer M
Smaart Control® in FIR Designer
The Moving Mic Measurement (MMM) Method
A moving microphone measurement is a practical and efficient way to capture a spatially averaged response using a single microphone. Instead of taking multiple measurements at fixed positions and averaging them, the microphone is moved continuously through the listening area while the measurement is being averaged.
This approach can provide a representative result of the listening space with significantly less setup time.
Measurement Configuation & Capture
Follow these steps to capture a moving microphone measurement using Smaart and FIR Designer
- Configure averaging in Smaart
Select either a Spectrum or Transfer Function measurement and set its Averaging to Infinite (Inf). This allows the measurement to continuously update as the microphone is moved.
- Enable streaming in FIR Designer
Open the Smaart Control dialog in FIR Designer and enable live streaming to the Smaart Streaming plot.
- Set the Reset Delay
Configure the Reset delay to match the time it takes to walk from the computer (running FIR Designer) to the measurement position.
- Configure Auto Grab
Enable Auto grab, and set the Grab delay to the desired measurement averaging time (typically 30-120 seconds). This determines how long Smaart will average the microphone signal before the measurement is captured.
- Select Reset Average in FIR Designer.
- Walk to the measurement position
- Slowly move or wave the microphone throughout the listening area.
When moving the microphone, avoid stopping it in one position for long periods (this can bias the average towards that location) or making any rapid movements (which may introduce handling noise).
After the Reset delay + Grab delay time has elapsed, the measurement is automatically captured and added to the Grabbed Measurements list.
Settings for Moving Mic Measurements in the Smaart Control dialog within FIR Designer
Using The Measurement
Any captured measurement can be selected from the Grabbed Measurements list, and transferred with a single click to the Import tab, Target tab or Averaging tab in FIR Designer. From there, it can be used directly within the FIR Designer workflow for filter & DSP design.
Further Reading
This technique is discussed in more detail in several published articles, including the Audio Engineering Society paper:
“Moving Microphone Measurements for Room Response in Cinema”
Authors:
– Paul Peace (Community Professional Loudspeakers)
– Shawn Nageli (Harman International)
– Charles Sprinkle (NXC Systems)
Note: Access to this paper requires an AES login.
Related Questions
No. FIR Designer does not capture loudspeaker or audio system measurements directly. The Smaart Control feature provides remote control of Smaart® from within FIR Designer, but capturing measurements requires a licensed copy of Smaart.
However, Smaart is not required to use FIR Designer. The software can import measurement data from a wide range of acoustic and loudspeaker measurement applications, allowing you to design DSP filters using measurements captured with your preferred measurement system. See the full list of supported measurement import formats.
No. FIR Designer cannot capture measurements (either fixed-position or moving-microphone measurements), unless its via Smaart Control. FIR Designer is DSP design and optimization software, not a measurement tool.
Most audio professionals already use dedicated measurement software (such as Smaart®, SysTune, Easera, or REW) to collect data. If you’re not using Smaart Control for measurement capture, FIR Designer can import pre-existing measurement data in a wide range of file formats, allowing you to continue using your preferred measurement tool.
No. Smaart Contol is only needed when live-streaming active measurement data. If you already have Smaart data saved as either Spectrum (*.srf) or Transfer function (*.trf) files, use the ‘Import’ tab to manually upload the data into FIR Designer.
The file format determines what measurement data is imported into FIR Designer. Smaart spectrum files – both single channel and average – contain a magnitude-only spectrum which is loaded as frequency (Hz) and magnitude (dB) with the phase set to 0 (degrees). Transfer function files contain various data elements including the complex spectrum, which is loaded as frequency (Hz), magnitude (dB) and phase (degrees). They additionally include a coherence spectrum not present in Spectrum files.
This import tab video provides the step-by-step instructions for loading saved measurement files (in any Smaart or non-Smaart file format) into FIR Designer.
See the full list of supported measurement import formats.
A moving microphone measurement produces a spatially averaged frequency response that better represents the listening area than a single measurement taken at one fixed position. By continuously moving the microphone while the measurement is averaged, the influence of small position-dependent peaks and dips caused by room reflections and standing waves is reduced. This makes moving microphone measurements particularly useful when designing room correction filters and DSP equalisation intended for multiple listening positions.
Yes. Averaging multiple measurements taken at different microphone positions is a well-established alternative to using a moving microphone measurement. Both techniques aim to produce a spatially averaged response that better represents the overall listening area by reducing the influence of location-specific room effects.
The two methods are not identical. A moving microphone measurement creates a continuous average as the microphone moves through the space, whereas measurement averaging combines a number of individual measurements taken at discrete positions. The accuracy of the latter depends on the number and distribution of the measurement locations.
If you have already captured multiple static measurements, FIR Designer can average them directly in the Averaging tab. Alternatively, Eclipse Audio’s free Averager utility can be used to combine measurements before importing the result into FIR Designer or another DSP design workflow.
Smaart is a registered trademark of Rational Acoustics LLC, Connecticut, USA.
