EM Acoustics i-12 compact ULF subwoofer - Manual (Page 7)

7
i-Series Subwoofers User Manual
www.emacoustics.co.uk
Cabling
i-8 & i-12 subwoofers are supplied with Neutrik Speakon TM NL4 connectors, wired on pins 1+/1-. The 2+/2- pins
are connected to allow link-through with four core cables (also for use on the i-12 in dual-channel mode – see
page 8 for details). It is recommended that the resistance of your cable is less than one tenth of the nominal
system impedance. Given below are the recommended maximum cable lengths for different cross-sections and
impedances.
Conductor Cross Sectional Area Maximum Recommended Cable Length
4 ohms 8 ohms 16 ohms
1.0mm 2 11m 22m 44m
1.5mm 2 17m 34m 68m
2.0mm 2 22m 44m 88m
2.5mm 2 29m 58m 116m
4.0mm 2 44m 88m 176m
6.0mm 2 66m 132m 264m
i-12 – Impedance Selection
A recessed switch on the rear of the i-12 allows the user to select the impedance of the enclosure. Some
amplifiers are not capable of driving 2-ohm loads, and as such the i-12 can be set to a dual 4-ohm load if required.
In this form of operation, one drive unit pair is on pins 1+/1- and the other pair is on pins 2+/2-.
NOTE – when using dual 4-ohm operation, ensure your cable polarity is correct as severe damage can
occur if the two driver pairs are out of phase. If in doubt, check with very low level initially.
With the switch in the 2-ohm position, all four drivers are connected to pins 1+/1- and pins 2+/2- are connected to
allow link-through.