Early ISC Speaker Processor
Owner's Information - all models ©2004 ARX®
Connecting the ISC leads
--- Early Models with Red and Black leads
The Red and Black ISC leads, on 4 pin XLR connectors, plug into the corresponding sockets on the rear of the Control
Unit. The RED leads connect to the OUTPUTS of the LOW amplifiers, in parallel with the leads going to the LOW
speakers. The BLACK leads connect to the Outputs of the HIGH amplifier, in parallel with the leads going to the HIGH
speakers.
Pin configuration is Pins 1 and 2 - Red (Low), Pins 3 and 4 Black (High)
• Connect both RED leads to the LOW amp outputs, and both BLACK leads to the HIGH amp outputs. They are
not polarity sensitive and don’t mind whether they are connected to + or –.
• Make sure you don’t get these mixed up as you will end up with the LOW ISC controlling the HIGHs, and vice
versa, which can cause major speaker damage to the HIGH drivers.
• Make sure that the Channel A ISC leads are connected to the Channel A amplifiers, and Channel B leads to the
Channel B amplifiers, or you will end up with the Channel A ISC controlling Channel B and vice versa, which
can give very strange results AND CAN OVERDRIVE THE SYSTEM.
NOTE: If your amplifier has Black and Red output terminals, don’t attach one Black ISC lead to a Black
terminal and a Red one to a Red terminal. It won’t work and may cause damage.
• Work slowly and carefully, and take the time to get it right. It’s a good idea to mark all leads as you go, so you can
visually check all connections before powering up.
Also note that inputs and outputs on early processors, in keeping with the accepted standards of the time, were wired Pin
3 + (Hot), Pin 2 – (Cold), and Pin 1 Audio Ground
--- Later Models with White and Blue leads
The White and Blue ISC leads, on 6 pin XLR connectors, plug into the corresponding sockets on the rear of the Control
Unit. The WHITE leads connect to the OUTPUTS of the LOW amplifiers, in parallel with the leads going to the LOW
speakers. The BLUE leads connect to the Outputs of the HIGH amplifier, in parallel with the leads going to the HIGH
speakers.
These leads allow the Control Unit/Processor to monitor the output of the amplifiers, and to activate the protection
circuits if the power exceeds the maximum safe operating area of the speaker.
These units won’t turn on until you make
these connections!
The White and Blue ISC leads, on 6 pin XLR connectors, plug into the corresponding sockets on the rear of the Control
Unit. The WHITE leads connect to the OUTPUTS of the LOW amplifiers, in parallel with the leads going to the LOW
speakers. The BLUE leads connect to the Outputs of the HIGH amplifier, in parallel with the leads going to the HIGH
speakers.
Pin configuration is Pins 1 and 2 - White (Low), Pins 3 and 4 Blue (High), Pins 5 and 6 trigger a relay to activate the
Control Unit, and to turn it off if the leads are removed
• Connect both WHITE leads to the LOW amp outputs, and both BLUE leads to the HIGH amp outputs. They are
not polarity sensitive and don’t mind whether they are connected to + or –.
• Make sure you don’t get these mixed up as you will end up with the LOW ISC controlling the HIGHs, and vice
versa, which can cause major speaker damage to the HIGH drivers.
• Make sure that the Channel A ISC leads are connected to the Channel A amplifiers, and Channel B leads to the
Channel B amplifiers, or you will end up with the Channel A ISC controlling Channel B and vice versa, which
can give very strange results AND CAN OVERDRIVE THE SYSTEM.
NOTE: If your amplifier only has Neutrik Speakon output terminals, you will need to connect the ISC
leads to the speaker cables by splicing them into the speaker cable after the connector, or by making up a
Y connector, so that one Speakon goes to the ISC leads, and the other goes to the speaker cable.
• Work slowly and carefully, and take the time to get it right. It’s a good idea to mark all leads as you go, so you can
visually check all connections before powering up.
