5
5.4
Electrical Characteristics and Accessories
5.4.1
INPUT SIGNALS: SYSTEM PROCESSING
While KF700 Series processing can be implemented in most commercially available
Digital Signal Processors (DSPs), EAW’s MX8600 and MC8750 DSPs are recommended.
Processor settings for specific array configurations are available in a variety of formats
that can be programmed directly into many DSPs. Formats include text lists of parameters
as well as processor-specific presets. These settings can be found on the EAW web site:
ftp://ftp.eaw.com/Processing/.
Additionally EAW offers the KF700 Wizard also available on the EAW web site at
ftp://ftp.eaw.com/KF700Wizard/. This program requires you to enter critical venue
dimensions and your array configuration. It will then provide you with appropriate signal
processing parameters for that venue and array configuration.
Discrete left / right KF700 arrays that do not incorporate KF755 downfills require four
distinct channels of processing per side: one for each passband of the KF750 and an
additional processing channel for SB750.
Integrating KF755 downfills into left / right arrays requires two additional channels per
side with the low frequency drivers utilizing the same processor output as the KF750
low frequency drivers.
Integrating KF755 into left / right arrays as upfills calls for two additional processing chan-
nels per side for each row of upfill KF755s. They require only mid and high frequency
outputs because ample low frequency energy is provided by the KF750s. Each row
requires individual delay settings to provide a coherent sum of the loudspeaker outputs in
the balcony. Thus two rows of inverted KF755s require four processing outputs per side.
A more efficient though slightly more complex approach exists. The same upfill process-
ing (crossovers, equalization, delay) is used for each upfill row. Thus, two processing
outputs can be used to tune the mid and high frequency sections of all the upfills. These
outputs would feed the bottom row amplifiers directly with appropriate delay set in the
processing. The ouptuts would also feed two signal delays to provide slightly more delay
for the top row of upfills. The signal delays must be carefully chosen to ensure that their
inherent propagation time plus the delay in the processor does not exceed the desired
delay for the top row of upfills.
A large KF700 Series array comprised of SB750 subwoofers, multiple rows of KF750s,
KF755 downfills, and 2 rows of KF755 upfills normally requires 8 to 10 distinct processor
outputs.
5.4.2
POWER AMPLIFIER REQUIREMENTS
All drivers (transducers) in the KF700 Series are rated based upon the results of a power
handling test procedure that is derived from the AES standard, but with a number of
important differences. Stephen Siegel, VP Engineering, outlines the specifics of the EAW
power testing procedure in the EAW Engineering Application Note ”Understanding
Loudspeaker Power Handling and Selecting the Proper Power Amplifier.” This can be
found on the EAW website.
5.4.3
DRIVER SPECIFICATIONS:
Passband
Impedance
Power Handling
Sensitivity
SUB (each driver)
8 ohms
1000 W
98 dB
LF (each driver)
8 ohms
600 W
97 dB *
MF 8 ohms
400 W
109 dB
HF 8 ohms
200 W
116 dB
* Sensitivity for the KF750 LF section with both drivers operating is 100 dB.
