Harman Kardon AVR75 Owners Manual - Page 31

Advanced Features 29 3. Subtract the distance to the surround speakers from the distance to the front speakers. a. When setting the delay time for the Dolby Digital surround mode, the optimal delay time is the resulting figure. For example, if the front speakers are ten feet away and the surround speakers are five feet away, the optimal delay time is figured as 10-5=5. Thus, in this example, the delay should be set at five milliseconds. b. When setting the delay time for an analog surround mode (Pro Logic, Hall, Movie or Matrix) take the result of the subtraction and add 15 to obtain the optimal delay time. For example, if the front speakers are ten feet away and the surround speakers are five feet away, the optimal delay time is figured as 10-5+15=20. Thus in this example, the delay should be set at twenty milliseconds. The Dolby Digital mode also provides a separate setting for the center channel delay mode, since the discrete nature of Dolby Digital signals makes the location of the center channel speaker more critical. To set the delay for the center channel, measure the distance from the preferred listening position in the center of the room to both the center channel speaker and either the left or right speaker. If the distances are equal no further adjustment is required and the center delay should be set to zero. If the distance to the front speakers is greater than the distance to the center speaker you may wish to reposition the speakers by moving the front left/right speakers closer to the listening position or the center speaker further away from the listening position. If repositioning of the speakers is not possible, adjust the center delay time so that you add one millisecond of center channel delay for each foot that the distance to the center speaker lags behind the front speakers. For example, if the front left/right speakers are each 10 feet from the listening position and the center channel speaker is 8 feet away, the delay is figured as 10-8=2, suggesting an optimal center delay of 2 milliseconds. The factory settings for the delay times are shown in the chart on page 31. If the use of the formulas described above or your own experimentation and preferences suggest that the delay time be changed, the adjustment is made from the SURROUND MODE menu. Reach the menu by pressing Select j and then pressing the ¤ button i once so that the on-screen cursor > is next to the SURROUND MODE line and then press Select again. The SURROUND MODE menu (see figure #15) will then appear. If you wish to change the surround mode before proceeding, use the ‹ or › buttons i until the desired mode is highlighted in reverse video. Next press the ¤ button so that the cursor is next to CENTER CH or SURROUND CH. (Note that center channel delay may only be adjusted in Dolby Digital mode.) Press the › button i until the desired time is highlighted in reverse video and then press ¤ until the cursor is next to RETURN TO MAIN MENU and press Select j. Other adjustments may now be made, or move the cursor to MENU OFF and press Select to exit the menu system. Digital Audio Playback Dolby Digital Dolby Digital (also known as AC-3) is the latest advancement in surround sound technology, delivering up to five fullrange surround channels (left, center, right, left surround and right surround) plus a special dedicated Low-Frequency Effects (LFE) channel. This represents a major advancement over traditional analog surround in that each surround channel is fully discrete and capable of full bandwidth reproduction. Dolby Digital is available on DVD and LV discs, and it will be a part of the new high definition television (HDTV) system when digital broadcasting begins in 1998. Dolby Digital for the home is based on the same system used to deliver digital audio soundtracks in movie theaters, enabling true cinema reproduction in your home. To utilize the Dolby Digital mode you must have a digital source properly connected to the AVR75. The RF digital output of a laser disc player should be connected to the AC-3 RF jack a on the rear panel. Note that this jack is for use only with the RF output from an LV player and should not be connected to any other audio, video or digital device. Digital datastream outputs from DVD players, HDTV receivers and CD players should be connected to the AC-3/PCM Optical or Coaxial inputs on the rear panel ° ·. In order to provide a backup signal and a source for recording, the analog outputs provided on digital source equipment should also be connected to their appropriate inputs on the AVR75 rear panel. (e.g., connect the analog stereo audio output from a DVD to the DVD inputs • on the rear panel when you connect the digital outputs). When playing back a digital source, first select the input using the remote or front panel controls d48)!. Next select the digital source by pressing the appropriate Digital Input button 9g. When the digital source is playing, the AVR75 will automatically detect