RX-DP20VBK/RX-DP15 -- THX Ultra2 THX Ultra2 provides a specification for equipment using the latest Dolby Digital Surround-EX and DTS-ES 6.1 channel soundtracks, presenting a movie closely to the director's original cut when it's played at home. The RX-DP20VBK and RX-DP15 bear the THX Ultra2 logo, certifying that they satisfy the newest certification standards of Lucasfilm Ltd., governing performance, features, sound quality, power, stability for driving low-impedance speaker loads, and ease of operation. THX Ultra2 offers THX Cinema and THX MusicModes that use seven channels of amplification for playback of multi-channel-encoded sources over a 7.1-channel layout. In 'Cinema mode', THX Ultra2 converts Dolby Surround Pro Logic matrix-encoded stereo and 5.1-channel soundtracks into 7.1-channel soundtracks. In 'MusicMode', 2-channel audio programs are converted into 7.1-channel surround sound for a compelling multi-channel audio experience.