Brochure

System Confi guration
Speaker and Microphone
Arrangement
Product List
Block diagram
AFC Concept
Increasing the sound energy density can extend the reverberation time
in a room.
AFC utilizes the acoustical feedback of a system to increase the energy
density of diffused sound. Reverberation time and sound energy
density can be controlled with transparency while preserving the
original acoustical characteristics of a room.
This technique distinguishes AFC from other enhancement systems.
FIR Filter EQ
Gain
Speaker
Microphone
Player
Listener
Using feedback loop including
original room sound
EMR
EMR (Electronic Microphone Rotator)
Since AFC utilizes acoustical
feedback, it is essential to prevent
coloration problems caused
by a closed loop condition
and maintain a stable system.
In order to ensure controlled
loop gain and a suffi cient
margin against instability, AFC
implements a special patented
technique called Electronic
Microphone Rotator (EMR).
EMR(Electronic Microphone Rotator)
Mic to speaker balance ratio is varied periodically
1
2
3
4
Microphone
ABCD
Microphone
3
4
A
Output
channels
SUM
2
VCA
2A
VCA
3A
VCA
4A
1
Voltage
VCA
1A
Time
Power Amplifier 22 ch Power Amplifier 32 ch
Loudspeakers 22 ch
Loudspeakers 32 ch
Switching Hub
Controller (ICP1)
RS422
Controller (ICP1)
HA
&
AD
MIC
Assign
EMR FIR PEQ1 PEQ2
Limiter
Delay
Level Matrix
4 in x 22 out
Level Matrix
4 in x 32 out
PEQ 22 ch PEQ 32 ch
Delay 32 ch
DA32 ch(8 ch x 4)
Delay 22 ch
DA 22 ch (8 ch x 3)
AFC3-1 AFC3-2
AFC3 Processor
Microphones
Controller Controller
LAN Switch
Power Amplifier Ceiling Speakers
Microphone
Loudspeaker
Audience Area
Stage
Under Balcony
Equipment Num. of Units ItemBL Description
1
Microphone 4 Omni-Directional Type
2
Head Amp & AD 1 AD8HR 8 ch HA-AD Unit
3
AFC Core Unit 2 AFC3 AFC Signal Processor
4
FIR Component 1 AFC FIR Card 4 ch FIR Card
5
DA Interface – 8 ch 6 MY8-DA96 8 ch DA Card
6
Cascade Cable 1 CAS003
7
Dsub25P to Analogue XLR 6 (Breakout Cable)
8
Amplifi er 11 XMV4140 Power Amp 4 ch
9
Stage Loudspeaker 8 IF2205 2-Way, Passive Mode,with 2 x 5" Woofer
10
Audience Loudspeaker 36 VXC8 8” Coaxial 2 Way Bass Refl ex
11
Controller 2 ICP1
3
Active Field Control
AFC3
4
Active Field Control
AFC3
AFC3 Core Unit
The AFC3 core unit is based on Yamaha’s well-known DME64N digital mixing engine.
The enhanced AFC3 version of this processor includes the expected matrix mixers, delay
lines, parametric EQ’s, and routing functions as well as specialized DSP components
developed specifi cally for AFC applications. While one card slot of the AFC3 processor
hosts a card dedicated to the FIR processing functions, the remaining three MY-card
slots provide the fi rst 22 channels
of outputs to the AFC system.
Additional AFC3 units may be
added and linked to the master
unit for additional outputs.
AFC FIR Card
The AFC-FIR card is used to realize the
high density of FIR processing that was not
previously possible. AFC3 systems with the
AFC-FIR card are capable of working with
FIR fi lter sets that contain 125 times as many
taps as previous AFC systems. This increase
in the size and density of the FIR fi lter
sets available make it possible to achieve
much longer increases in a room’s natural
reverberation time without unnatural
sounding artifacts.