Smaart I-O

The production of the Smaart I-O was discontinued in September 2017.

The Smaart I-O is a measurement-grade 2×2 USB audio interface designed aSmaart I-Ond built specifically for use with Smaart Measurement Software.  The I-O features two high-quality, active balanced inputs with 50 dB of computer adjustable gain in precision 1 dB steps.  These input gains are monitored directly by Smaart allowing the user to retain accurate SPL calibration while varying measurement signal input levels. As a class-compliant USB audio device, the Smaart I-O uses the operating system’s built-in audio I/O drivers to communicate with Smaart and other audio-related programs.

The inputs employ a Neutrik combo jack (XLR / ¼”) to accommodate both mic and line level input signals, each with switchable 48V phantom power on the XLR inputs for measurement mics and a 20 dB pad on the ¼” to accommodate line level signals. The Smaart I-O also features two active balanced XLR outputs capable of providing +8.2 dBu (2 Vrms) max level signal for playback or excitation sources.

Powered by the USB port of your computer (or via the optional 5 VDC jack), the Smaart I-O provides a compact and portable measurement-quality input for your Smaart rig.

Smaart I-O Features:

  • Two (2) Neutrik XLR – ¼“ combo jack inputs:
    • Computer controllable 50 dB analog gain in precision 1 dB steps
    • Max input (at minimum gain): +6 dBu  (XLR),  +26 dBu (¼ ”)
    • Active balanced with 2k ohm impedance (XLR), 65k ohm (¼ ”)
  • Two (2) Active Balanced XLR Outputs
    • 150 Ohm impedance
    • Max Output : +8.2 dBu (2.0 V rms) w/ 100k ohm load
  • Frequency Response
    • Magnitude :  16 Hz – 20 kHz, +/- .25 dB
    • Phase:  16 Hz – 20 kHz, +/- 10 deg
  • Sample rate clocks of multiple I-O’s can be linked to allow for device aggregation in Smaart’s dual-channel measurements.
  • Bus powering via USB for convenient, single-cable connection to the computer.
  • Optional 5 VDC jack in cases of insufficient USB power
  • Dimensions:  1.75” (h) x 7.25” (w) x 4.25” (d)

Smaart I-O backsmallSmaart I-O frontsmall





The Smaart I-O is available for purchase via the Rational Acoustics Online Store (discounted Smaart v.7/Smaart I-O combo packages available) or from any authorized ScandinavianSmaartPartner.


Smaart I-O Control Application

Note:  To use the Smaart I-O Control Application with Smaart, you will need to have Smaart v.7.3.2 or later, or Smaart v8 installed on your computer. To update to the latest version of Smaart, log-in to your license management account at and download the latest installer.

I-O Windows




Smaart I-O Firmware

Click the link below to download the latest firmware package for the Smaart I-O. Before attempting to update the firmware on your device, please read the document “Smaart I-O Firmware Update Procedure

01/01/12 Version 1.0 Firmware

This firmware update fixes intermittent issues with noise and latency on the Smaart I-O inputs when connected to a computer running OSX 10.7 or 10.8. The update is recommended for all Smaart I-O users, even if you are not using a Mac computer.

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