Comparison To A Distributed System - Community ENTASYS Application Manual

CO M PARI S O N TO A D I ST R I B U T E D SYSTE M
In the final design example we will compare an ENTASYS system design of a typical distributed system using overhead-
mounted loudspeakers. Our example employs a moderately sized multi-purpose room with no acoustical treatment and a mid-
band RT of about 1.5 seconds. The primary application of this sound system is for speech, with occasional playback of pre-
recorded material or background music. Assuming a limited budget, an absolute minimum number of loudspeakers will be
specified for each design to achieve the required coverage.
Community iBOX i2W8T multipurpose/under-balcony loudspeakers are used for the distributed overhead design. These
loudspeakers extend a bit more than an octave below the cut-off frequency of ENTASYS. A low frequency extension
loudspeaker may be added to the ENTASYS design if desired, with no detrimental effects.
ENTASYS Design Approach
For the ENTASYS design, a single array is placed along the center of the front wall, thereby ideally locating the front of the
audience area about 13 ft (4.0 m) in front of the loudspeaker. The audience area extends to a distance of about 75 ft (22.9 m)
away from the array.
The main audience area is drawn in EASE Focus (see Figure 45). An array utilizing two Full-Range modules above a single Low
Frequency module is positioned 11.3 ft (3.4 m) high and aimed straight back. Since no down-tilt or panning is required the
included ENTASYS T-brackets can be mounted directly to the wall. Small shims behind the upper portion of the array can
provide a moderate down-tilt if slap-back echoes develop.
The configuration and position of the array are transferred from EASE Focus to the EASE model. Since the array is placed at
the center of the front wall, no horizontal panning is required.
Results
The audience areas in Figure 46 exhibit fairly uniform coverage at approximately 97 dB (+/- 2 dB). Only a few seats at the
front inside corners of the two audience areas (along the center aisle) reach a higher SPL of around 101 dB. The system
exhibits good potential intelligibility with a C50 averaging 1.5 dB (+/-1.5 dB). The STI is approximately 0.60 with the %Alcons
being about 6.8%. Listeners will perceive the sound as coming from the front of the room where primary focus of the
presentation will be.
Loudspeakers and Power Amplifiers Used in This Design
One array of a Full-Range module (curved top), above a second Full-Range module (curved bottom), with a Low Frequency
module at the bottom.
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(2) ENTASYS Full-Range Modules (ENT-FR)
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(1) ENTASYS Low Frequency Module (ENT-LF)
•
(1) One channel amplifier rated at 3,600 W into 4 ohms
•
(1) High pass filter or DSP unit
•
(1) Optional subwoofer or low frequency extension loudspeaker
•
(1) Optional one channel amplifier at 900 W into 4 ohms and HPF/LPF for the subwoofer
DESIGN APPLICATION EXAMPLES
Community ENTASYS Application Guide - Page 50