Crate Amplifiers SPA-1400 - Manual (Page 18)

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SPA-1400/1400C
Rack Mount Power Amplifier
Speakon ® is a registered trademark of Neutrik USA
Installation and Operation:
Biamping: SPA-1400C – Two Mono Bridged Amplifiers:
A pair of SPA-1400C can be used to power separate low and high frequency cabinets. The BRIDGE MONO SWITCH (#17)
of each amplifier must both be in the IN position. Use one amplifier for the low frequencies and the other for the highs. Since
the SPA-1400C has a built in active electronic crossover, a separate external electronic crossover is not needed – run the out-
put from the mixer directly into channel 1 of the low frequency amplifier.
Connect channel 2’s BALANCED THRU/X-OVER OUT jack (#18) of the low frequency amplifier to the INPUT of the high fre-
quency amplifier. The X-OVER OUT/THRU switches (#19) must each be pressed in. Use the CROSSOVER FREQUENCY CONTROL
(#24) of the low frequency amplifier to set the cut off frequency for the low frequency cabinet. (You may alternately use the
first SPA-1400C as the high frequency amp if you set the
LOW/HI SEND SWITCH (#22) to “2/1” and reverse the cabinets from
what is shown below.)
Either the binding posts or the Speakon ® jacks may be used to connect the amplifiers to the speakers. See the wiring dia-
gram below for the Speakon ® jacks.
NOTE: Your speakers may benefit from a low frequency cut, since frequencies below a speaker’s low-end response limit can
cause distortion or even damage. For this reason you might consider using an appropriate Low Cut Frequency (see #20 & #21)
with your speakers (SPA-1400C only). (Even some subwoofers perform better with an appropriate low frequency cut.)
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