The Monitor XT20 is a two-way passive bookshelf speaker built around a 6.5-inch bilaminate paper woofer and a 1-inch Terylene dome tweeter. The woofer is described as Dynamically Balanced and is aimed at open midrange and punchy bass with low distortion. It is the larger of the two bookshelf models in the Monitor XT line and reaches about a half octave lower than the compact MXT15.

The tweeter extends the response to 40 kHz, and the speaker carries Hi-Res Audio certification for use with high-resolution streaming, movies and games. The frequency response is stated as 38 Hz to 40,000 Hz, with a 3200 Hz crossover and 87 dB sensitivity. Low-resonance cabinets are part of the design. It is Dolby Atmos certified and DTS:X compatible, and the MXT90 height module can be added for 3D sound.

Connection is through 5-way nickel-plated binding posts. It works with 4- and 8-ohm outputs and with AV receivers or stereo amplifiers delivering 30 to 200 watts per channel. A black finish is offered, and the pair is supplied with an owner's manual, info sheet and quick start guide available as downloads.