The Smaart I-O is a measurement-grade 2x2 USB audio interface designed and built specifically for use with Smaart v7 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. The Smaart I-O employs Neutrik combo jacks (XLR / 1/4-inch) to accommodate both mic and line level inputs, each with switchable 48V phantom power on the XLRs for measurement mics and a 20 dB pad on the 1/4-inch 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.