Presonus StudioLive RM32AI 32-Channel Rack Mount Digital Mixer+Studio Headphones 32-Channel Rack Mount Digital Mixer with 32 Preamps. Fully recallable digital mixer. Inputs and Outputs:32/16 locking XLR inputs, each with: Recallable XMAX Class A mic preamps. 48V phantom power. Stereo tape input (RCA jacks). 16/8 XLR line-level Mix outputs, Four 300 ms alignment delays on the last four Mix outputs. 2/1 DB25 jacks mirror 16/8 line-level Mix outputs 3 XLR main outputs (left, right, mono/center) with analog trim pots. S/PDIF digital output on removable option card. Headphone output with volume knob and selectable source. 1x1 MIDI I/O (for future implementation). Channels and Buses . 32 internal channels. 25 mix buses. Fully integrated, continuously bidirectional, 52-in/34-out, FireWire 800 direct recording interface (24-bit, 44.1/48/88.2/96 kHz) Microphone Preamp. Input Type: XLR Female, balanced, locking. Frequency Response to Direct Output (at unity gain): 20-40 kHz, 0.5 dBu. Frequency Response to Main Output (at unity gain): 20-20 kHz, 0.5 dBu. Input Impedance: 1 k. THD to Main Output (1 kHz at unity gain): 0.005%, +4 dBu, 20-20 kHz, unity gain, unwtd. S/N Ratio to Main Output (Ref = +4 dB, 20 kHz BW, unity gain, A-wtd): 94 dB Pro Professional Studio Headphones. Semi-open, diffuse-field studio headphone. Analytical sound. Comfortable fit due to rugged, adjustable, soft padded headband construction. Robust, easy serviceable construction as all parts are replaceable. Single-sided cable. Velour, circum-aural (around the ear) ear pads. Supplied in a carrying bag. Transmission type Wired Headphone design (operating principle) Semi-open. Headphone impedance 250 ohms. Headphone frequency response 5 - 35.000 Hz. Nominal sound pressure level 96 dB. Construction Circum-aural (around the ear). Cable & plug Coiled connecting cable with mini-jack plug (3.5 mm) &  adapter (6.35 mm). Net weight without packaging 295 g