Theta Digital Casablanca III HD, Owner'S Manual

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Step by Step Speaker Configuration
Casablanca III HD provides a comprehensive set of speaker configuration settings. These settings are believed to be
the most complete ever offered in a home theater component and should allow any speaker to perform optimally
regardless of speaker type. The following procedure is merely a guideline: room acoustics, speaker design/quality,
music/film type, and personal preferences all have a part in these settings.
Using the Setup menu map diagram [Figure 11] on page 18 in this manual is recommended.
There are four major steps to setting up your Casablanca III HD. In recommended sequence, they are:
Speaker Configuration & Crossovers: permits proper signal routing in the Casablanca III HD and proper blending of
main and subwoofer signals. Enables all speakers present in the system.
Individual speaker levels: compensates for different speaker and amplifier efficiencies.
Delays: compensates for different speaker distances from the listening position.
Input Specific Setup: All parameters that are specific to an individual input select button.
Each step plays a pivotal role in the overall sonic performance and should receive equal attention and care in
adjustment.
Speaker Configuration & Crossovers
Crossovers are most commonly located in a speaker cabinet. Their
purpose is to keep energy at certain frequencies from reaching specific
speaker elements (drivers), [e.g. keeping unwanted bass energy from the
tweeters (see diagram at right).] Home theater applications use
crossovers in the surround processor to send low pass information to a
subwoofer and limit the low pass information sent to the main speakers.
The purpose of this section,
SPEAKER CONFIGURATION , is to properly
set up the Casablanca III HD’s internal crossovers for optimal sound as
well as enable all speakers in the system.
In this manual, a Speaker Set is defined as one or more speakers that are
manipulated via a common parameter. For example, the crossover
parameters for both the front left and right speakers are manipulated in the front left/right configuration submenu since
the desired effect for the left speaker is also appropriate for the right. The other speaker ‘sets’ in the Casablanca III
HD are the [surround left and right], the [side left and right], the [center] and the [center surround]. The speaker sets
will be delimited by [ ].
Full speaker configurations are stored separately for each of the 12 input select buttons. This procedure will guide the
user to set all configuration parameters for input # 1, and then copy these parameters to all other input select buttons.
In the Speaker configuration submenu, buttons 1 - 5 will access additional menus to setup a particular speaker or set of
speakers. Button 6 will turn on the side speakers, if configured in the system. In each speaker set’s configuration
submenu, pressing button # 5 will allow a change of the crossover type for that speaker set. There are three options
for the crossover type: "Phase Perfect"; "Butterworth"; and "Linkwitz-Riley". Each crossover type has settings that are
applicable only to that type. The Front [Left/Right], [Center], [L-R Surround] and [Center Surround] speaker
configuration submenu contains a separate setup submenu for each of the three crossover types. It is recommended
that each of the three crossover submenus be set up for each speaker. The user can then audition each crossover
type to determine which sounds best on their system.
Following is a description of each crossover type to help the user better understand the sonic advantages of each:
Phase Perfect
This is a term coined for a type of crossover wherein the low pass portion is derived from the high pass. First, a high
pass Butterworth crossover is performed. This gives two resulting signals: the high pass and the original, unaltered
signal. Then, the high pass signal is subtracted from the original input signal, resulting in the low pass signal, which is
usually routed to the subwoofer. An advantage of a Phase Perfect crossover is that if the high and low pass signals
are added together, an exact replica of the original input signal results, thus the term "phase perfect". A potentially
negative attribute of this type of crossover is that, due to phase relationships and vector mathematics, higher order
filters (12, 18, 24 dB/octave) always produce 6dB/octave low pass slopes, in terms of electrical energy sent to the
subwoofer. The high pass portion will have the expected 6, 12, 18 or 24 dB /octave slope. Due to this phenomenon,