Indianapolis - THX revealed more details about its first performance standard for soundbars, pointing out that active and passive models would qualify for its certification mark but that all would likely require the use of an active subwoofer.

The certification standard would join standards for A/V receivers and HTiB systems.

The standard calls for flat response from 35Hz to 20kHz through a two- or three-channel soundbar, reference sound levels of a minimum 85dB with 20dB of headroom at a viewing distance of six feet, a smooth blend between satellite and subwoofer drivers, and controlled horizontal and vertical dispersion to minimize distortion-inducing floor, ceiling and wall reflections, technology operations VP Peter Vasay told TWICE. The dispersion requirements would optimize sound reproduction for viewers sitting anywhere on a couch that's 6 feet from a TV, he noted.

The crossover level between subwoofer and satellite drivers is low enough to minimize location changes in voices and instruments.

The standard also calls for a minimum of two stereo analog connections. Digital inputs are optional. The standard does not require the inclusion of any virtual surround technologies or embedded surround-sound decoding, he added.

Reference dB levels are optimized for rooms with a volume of less than 2,000 cubic feet, whereas the HTiB standard is designed for rooms of 2,000 cubic feet with sound pressure levels of 85dB with 20dB of headroom at a viewing distance of 10 feet.

The first soundbar meeting the standards is an active model from direct-to-consumer speaker supplier Teufel, which sell only in the European Union. That model, on display at CEDIA Expo, is an active 2.1 system with 350-watt output, separate subwoofer, and analog and digital inputs.