Audio Design Associates Cinema Reference Mach II PTM-8150 - Manual (Page 46)

Page 45
Speaker Size Setup 1
Once you have your inputs configured properly, you will need to setup the Cinema Reference Mach
II’s outputs which pass to your power amplifier and then the speakers. In this section, you will need to
proceed with several steps that focus on the type of speaker you are using in your system.
The Cinema Reference Mach II uses the description of SMALL, LARGE, and NONE with respect to
the speakers.
SMALL refers to speakers that are not designed to handle low frequencies.
LARGE refers to speakers that are capable of playing low frequencies.
NONE refers to that speaker not existing in your system (i.e. no back-center surround speakers)
There is another Cinema Reference feature that works in conjunction with SMALL settings called:
SW CROSSOVER which refers the Sub Woofer crossover frequency point.
The subwoofer crossover frequency point determines at which frequency the Small speakers bass
information is “rolled off” and sent to the subwoofer. Speakers that are set to Large are never rolled
off. The crossover frequency point is fully adjustable on the Cinema Reference Mach II and is dis-
cussed in the tail end of this section.
What type of speakers are your using?
If you are using THX speakers, most such speaker designs are purposely engineered to not handle
low frequencies because the subwoofer is providing all of the bass sound reinforcement. The typical
crossover frequency point for THX speaker is 80Hz (Hertz). In a THX speaker system, all bass infor-
mation below 80Hz intended for the left, center, right, surround left, surround right, back surround left,
and back surround right speakers is redirected to the subwoofer and summed (combined) with the
LFE (Low Frequency Effects or the “.1” in a 5.1 mix). As such, these speakers are rolled off at 80Hz.
If you have a mix of home theater speakers and full-range speakers (speakers that can handle bass),
you can opt to set some speakers to the Large setting and other speakers to the Small setting.
The Cinema Reference groups speakers as such: the front left and right are one group, the center
speaker is a second group, the surround left and right speakers are a third group, the back left and
right surround speakers are fourth group, and subwoofer is a fifth group.
Prior to proceeding with the speaker setup for your system, here are a few considerations.
a ADA generally recommends that all speakers are set to small for the optimum theater experi-
ence, even if some of your speakers are full range. This suggestion coincides with the under-
standing that your system contain at least one subwoofer and that it is a quality subwoofer.
The reason behind this suggestion is based on two considerations. First, most bass informa-
tion in film content is mixed into the front left and right channels as well as the “.1” LFE channel.
By directing all of the bass information to the subwoofer, you will create a more theater-like
experience. Second, the subwoofer control section of the Cinema Reference Mach II is ex-
tremely powerful, giving you extensive control of all bass information.
b While systems can be run in a phantom mode, where the center channel information is redi-
rected to the front right and left speakers, ADA strongly suggests that you utilize a center
channel speaker in your system. As this channel handles mostly dialogue, it is an important
speaker in your system.