The recently opened Karbala Olympic Stadium in Iraq is a 30,000-seat venue
designed to host major sports, music, religious and youth events. Audio for the
project was provided by Baghdad-based APCO Electronics, which provided acoustics
design and participated in the actual installation as well. The company chose a
sound system from Electro-Voice, creating a multi-zone digital audio system based
around the IRIS-Net system control and supervising software and Electro-Voice
EVH-1152 horn-loaded loudspeakers. The selected sound system stands for
reliability, superior sound quality and scalability to future requirements. In addition,
Electro-Voice amplifiers, microphones and wireless systems were also utilized.

The primary system requirement was that the sound system would meet FIFA
football standards, which require 92 percent direct coverage and high intelligibility,
with a Speech Transmission Index (STI) of 0.50 or higher. The installed system
exceeds those standards, delivering 95 percent coverage with an outstanding STI
(Speech Transmission Index) rating of 0.80, indicating excellent speech clarity. Next
to public address announcements, the system should also be used for voice alarm
and evacuation purposes.

Using EASE simulation software, the APCO team developed a design based on the
Electro-Voice EVH-1152 loudspeaker system, a two-way 15-inch horn-loaded design
available in six dispersion patterns. For the specific grandstand angles at Karbala
Olympic Stadium, APCO used 24-each of 60×40-degree and 90×90-degree coverage
patterns. Paired together, this combination provides direct, full-range coverage to
all seating locations, including the difficult corner areas. In addition, two EVH-1152
loudspeaker systems with 90×90-degree dispersion are deployed individually at
either end of the field to deliver audio onto the playing surface as needed.

The entire sound system is networked together using Electro-Voice N8000 Dante-
enabled DSP matrix controllers and powered by Electro-Voice CPS series amplifiers
with RCM-810 remote control modules. The N8000 from Electro-Voice provides
complete system routing and control via graphical user interface in IRIS-Net
software. The main loudspeaker system is divided into four zones, each with its
own N8000 from Electro-Voice and either three or four amplifiers, with the east side
zones requiring and extra amplifier to feed the field speakers. All amplifiers are
connected to their associated N8000 via a gigabit Ethernet switch to handle signal
routing, with redundant connectivity to ensure a reliable digital network. A fifth
N8000 is stationed in the stadium’s main control room, and acts as the master unit
for the entire system, routing the audio to each of the four individual zones. APCO
programmed the signal processing core to handle all required audio sources,
including microphones, PC-based streaming audio, emergency notifications and
scoreboard audio.

Karbala Olympic Stadium represents the largest Dante system that APCO Electronics
has designed and installed. Thus, the feeling of accomplishment was strong when
the APCO team finally heard the Iraq national anthem being played through the
Electro-Voice system at the opening ceremonies. That feeling was reinforced shortly
after the event when APCO received calls from the Minister of Youth and Sport, and
from local broadcaster Ishtar Media, thanking them for the outstanding audio

APCO Electronics: