This document describes the additions and changes found in the DTS and Dolby Digital (Version 2.00) firmware for the Lexicon DC-1. Features unique to the DTS version will be noted: (DTS version only). Although the changes may appear minor at first, significant changes were made to further the DC-1 towards the goal of building an optimum processor for film and music.
The additions and changes fall into these two categories:
1) Effect additions and changes.
2) Input Configuration additions and changes.
1) Effect additions and changes
The new firmware includes several improvements and changes to the LOGIC 7, MUSIC LOGIC, TV MATRIX, and MUSIC SURROUND effects. While the new 5.1 formats represent a huge step forward in home entertainment, we realize that most people will spend most of their time listening to two channel music and 4:2:4 matrixed film sound. Therefore we have spent a tremendous amount of time developing sophisticated algorithms that provide extremely compelling and involving audio presentations from non 5.1 sources. We are particularly pleased with the results of our research and development as implemented in the LOGIC 7 and MUSIC LOGIC modes.
We have consulted with some of the top studio engineers and producers in the world, allowing them to audition a wide variety of material both of their own and others. With their feedback, our algorithms have evolved to a point that most of them, even the minimalist/purist contingent, are extremely impressed and pleased with the multi-channel presentation the DC-1 can provide from a two channel source.
Our main areas of concentration were the control of the width of the front hemisphere information and the overall envelopment and relative listener position in the resultant soundfield.
The "SOUNDSTAGE" control.
A "SOUNDSTAGE" control has been added to the MUSIC LOGIC, LOGIC 7, TV MATRIX and MUSIC SURROUND effects. "SOUNDSTAGE" changes the level of the surround channels relative to the front channels in a dynamic way. The control has three positions; "FRONT," NEUTRAL," and "REAR." Changing this setting moves the perceived seating position either forward or backward in the listening space.
The "SOUNDSTAGE" control is adjustable and its dynamic action is intelligent. The new algorithm detects if the source was originally surround encoded. It does this by looking for rear steered material, and detects the directional orientation of the background sound between strong sounds. The same detection and intelligence is utilized for the "SURROUND ROLLOFF" control, which controls high frequencies in the surround channels. High frequency attenuation of the surround channels is desirable for music and broadcast sources without surround encoding. However, when a surround source is detected these filters are removed, so the surround outputs reproduce surround events with full bandwidth.
The "FRONT STEERING" control.
The "FRONT STEERING" control is quite different from previous firmware releases and is reflected in the settings. "MUSIC," selects the music approach to front steering described below. "FILM," selects the film approach to front steering also described below. "½," selects the music approach, but limits the loudness of the center channel and the reduction of the center component in the left and right main channels. Under most conditions the "½" setting is the same as the "MUSIC" setting. However, if a radio or television broadcast has an announcer only, the "½" setting will cause the announcer to come from all three front channels. "OFF," sets the center channel level softer than the front left and right channels, and leaves the level unchanged as the steering varies. "OFF" is equivalent to conventional stereo with a slight center fill. Considerable research went into determining the ideal center channel properties in a surround system
When film sound is reproduced utilizing the "MUSIC" setting of the "FRONT STEERING" control, dialog may be reproduced by the left and right front channels, particularly if there is music or effects present at the same time. For a listener located far off axis there is a small apparent movement of the dialog as the steering changes. This small dialog movement is very subtle, but some may find it undesirable. For those listeners we have also included a "FILM" setting in the "FRONT STEERING" control.
The "FILM" setting has excellent image stability throughout the entire room during dialog and vocals, while preserving the full width of the front image in between dialog, and music without vocals. The front image during vocals with the "FILM" setting is narrower than with the "MUSIC" setting, but the results are highly satisfactory in any case.
In the new firmware, the LOGIC 7 effect is intended for playback of matrix encoded material, and the front steering is factory preset to "FILM,". In the MUSIC LOGIC and TV MATRIX effects, the "FRONT STEERING" control is preset to "MUSIC," but can be changed in the "EFFECT ADJUST" menu.
This approach for the center channel yields wonderful results on a variety of music material. It preserves the width of the front image even with complex material and high vocal levels. At the same time it reproduces film with better dialog intelligibility than traditional matrix decoders, maintaining adequate separation between the center channel and the left and right front channels during dialog.
NEW DTS Modes
DTS LOGIC 7 (DTS version only). This effect utilizes LOGIC 7 decoding technology to create 7.1 channels from DTS sources. The improvements over standard DTS decoding are not subtle, and is highly recommended for any systems utilizing side and rear channels. Greater envelopment and sense of movement are achieved when the listening area is completely immersed in the soundfield where there is content dependent dynamic control of the side and rear levels.
DTS THX 5.1 (DTS version only). This effect includes Lucasfilms home THX enhancements for DTS, which are similar to the THX enhancements for Dolby Digital (AC-3) found in the THX 5.1 effect: Re-EQ of the front channels, adaptive de-correlation of the surround channels, and timbre matching between the front and surround channels. NOTE: when utilizing any "THX" effect in the DC-1, the rear outputs will mute unless "STANDARD (LARGE or SMALL)" is selected for the side speakers in the "SPEAKER CONFIG" menu. Selecting STANDARD or DIPOLE does not alter the signal sent to the side outputs.
DTS FILM (DTS version only). This effect allows customization for playback of DTS film material. Many DTS films are mixed using an LFE level 10dB lower than their music counterparts. The LFE MIX LVL allows user control of this parameter. The SIDE LEVEL control allows level/mute control of the side channels for regular DTS 5.1 channel playback.
DTS MUSIC (DTS version only). This effect allows customization for playback of DTS music material. Most DTS music discs are mixed using an LFE level 10dB higher than their film counterparts. The LFE MIX LVL allows user control of this parameter. The SIDE LEVEL control allows level/mute control of the side channels for regular DTS 5.1 channel playback.
DTS 2 CHAN (DTS version only). This effect utilizes LOGIC 7 matrix encoding to create a 2 channel down mix, to allow compatibility with existing two channel recording and listening devices. Playback of LOGIC 7 encoded material is optimized through the LOGIC 7 effect, but maintains compatibility with traditional matrix decoders (Pro-logic etc.), Stereo and Monaural.
2) Input Configuration additions and changes
EFFECT is now labeled PCM FX. Selections are the same as previous firmware releases.
DTS FX (DTS version only). Determines which DTS effect the DC-1 utilizes when a DTS encoded signal is identified at the input.
The following effects are pre-assigned in the INPUT CONFIG menu:
At any time these assignments may be changed via the INPUT CONFIG menu:
This controls the DC-1s auto effect loading and format only features. When set to AUTOMATIC, the DC-1 automatically loads the effect selected in the INPUT CONFIG menu. The format of the incoming signal will determine which of the three effects the DC-1 utilizes. In addition to auto effect loading, the new firmware does not allow effects to be utilized that do not support the format of the incoming signal. For example, if a DTS signal is coming into a DC-1/DTS, the effect up/down keys will only scroll through the 5 DTS effects. When set to PCM, Dolby Digital or DTS ONLY, the DC-1 will only playback signals and utilize effects that support that format.
NOTE (DTS version only): When AUTOMATIC is selected for FX FORMAT, and DTS source material is being utilized, there may be a brief burst of noise before playback begins. This is inherent in the current generation of DTS source material and does not represent a problem with your DC-1. To avoid this, set FX FORMAT to DTS ONLY, and use that input for playback of DTS source material.
In addition to auto effect loading, the DC-1 allows direct access for up to eight effects. The following effects are pre-assigned for direct access in the new firmware:
To load this effect Press this key combination on the DC-1 remote control
To change an assignment, the existing one must be cleared first. To clear an assignment:
To assign an effect to a cleared input:
Soft Patching Input Assignment Changes
DIGITAL is now labeled AUDIO IN. Selecting ANALOG is the equivalent to selecting NONE in previous firmware releases.
VIDEO is now labeled VIDEO IN. Selections have not changed from previous firmware releases.