KF760 Touring Usage Guide

K F 7 6 0 S E R I E ST O U R I N G U S A G E G U I D E

KF760 Series Touring Usage Guide

17 Aug 01 Page 1

0 INTRODUCTION

The KF760 Series Line Array represents a powerful, new second-generation line array technologyoptimized for use in portable sound reinforcement applications. Because the system is scalable,designers can create arrays as small as four enclosures or as large as 20.

Employing a technology we call Divergence Shading, a KF760 Series array will provide even SPLcoverage across radically different throw distances ranging from 15 feet to several hundred feet. Sonicquality will be uniformly excellent and pattern control will be maintained well into the low frequency range.

All this is achieved with a minimum of DSP, enabling an intuitive approach to array design. And sincesimple 1/3-octave EQ will usually suffice to tune the system, this intuitive quality extends to systemoperation, as well.

A simplified rigging system speeds set-up and teardown, while properly dimensioned caster pallets createa more uniform truck-packing environment.

This KF760 Series Touring Usage Guide will provide users with information on KF760 Series application,array design concepts, powering and processing issues, and rigging and transportation techniques.

EAW engineers paid great attention to details of life on the road, making the KF760 Series the simplest,most flexible line array system on the market.

1 OVERVIEW

Applications

The KF760 Series Line Array is engineered for concert touring use in venues such as arenas, largeballrooms, music pavilions, convention center exhibit halls, theaters, auditoriums, and flat field oramphitheater-style outdoor events. Using just two models (KF760 and KF761), designers can easilyreconfigure this scalable system for different size venues from theaters under 1,000 seats to large arenasand even outdoor stadiums.

KF760 Series Loudspeakers

The KF760 Series comprises just two loudspeaker models: the KF760 general purpose/longthrow moduleand the KF761 short-throw module. Like all other array-optimized EAW products, these loudspeakersystems are engineered for use in clusters and not as stand-alone devices.

Both are full-range, three-way, tri-amplified systems. The chart below illustrates some key factors,including subsystem components:

KF760 KF761LF dual 12 in horn loaded dual 12 in horn loadedMF dual 10 in horn loaded dual 10 in slot loadedHF dual 2 in horn loaded single 2in horn loaded

Nominal Cov. (H x V) 80 x 3 100 x 12Face to Face Angles 0, 1.5 or 3 0, 4, 8 or 12

Recommended Throw Distances 70 to 600 ft / 20 to 180 15 to 150 ft / 5 to 45 m

Horn design represents a key qualitative difference between the two models. The KF760 s horns areoptimized for long-throw capabilities while the KF761 s horns are optimized for smoothest sound in theextreme nearfield.


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2 Array and Overall System Design

The Basics

Much like the KF900 and KF750 Series, the KF760 Series isintended to create array columns that address the different verticalsections in their coverage areas (nearfield, main seating, longthrow, etc.). The minimum KF760 Series array comprises fourenclosures.

Both the KF760 and KF761 allow users to choose from differentface-to-face angle adjustments to create arrays with varyingcurvature. Thus, by using the different models and different face-to-face angles, designers can create arrays custom-tailored toeach venue s profile.

The basic approach to array design can be summarized as: flat-front KF760 s for longthrow sections

(0 face-to-face angle) increase curvature as distance decreases (1.5 or 3) transition to tight-packed KF761 s when you need

more arc/down-angle (12) add more enclosures for more output use recommended face-to-face angles only and do not

allow gaps between module faces

This approach focuses more transducers mounted on long-throwhorns (KF760 s) at the farthest seat, gradually focusing fewertransducers as distance decreases, and, ultimately, transitioning toshort-throw horns (KF761 s) as distance drops belowapproximately 50 feet.

As long as the no gap rule is maintained, arrays constructed according to these principles will provideeven SPL and a consistent sonic character throughout the venue without requiring complex processing.This approach is known as Divergence Shading , where the same amount of acoustic energy is spreadover a larger or smaller vertical angle depending on required throw.

This discussion represents, of course, just a basic approach. Given the infinite variety of venues andperformers, users will find themselves needing to solve specific problems in specific situations. As always,rely on your experience and common sense. Also, a KF760 Coverage Wizard designed to help calculateoptimum splay angles, aiming angles, and fly-bar pick points (crucial in aiming the array) for a givenvenue, will be discussed later in this Guide.

Where s All the Science? It s in the Box.

KF760 Series arrays require relatively simple signal processing, facilitating an intuitive approach both fordesign as well as operation. Simply design your array as described above, preferably with the aid of theKF760 Coverage Wizard, apply the recommended signal processing, and mix to taste.

The complexities of producing a coherent wavefront from multiple sources are effectively nullified bycertain factors designed into of the products. The following discusses these on a surface level. Fordetailed technical information on these technologies, consult the KF760 White Paper.


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Array Coherency

Producing a coherent wavefront from multiple enclosures containing multiple transducers represents theprimary challenge in array design. The KF760 Series seeks to reduce the apparent number oftransducers by:

physically and electronically aligning the transducers within a single enclosure so they appear asa single source

spacing transducers to maximize coupling employing horns that maximize coupling

Within each module (both KF760 and KF761), all transducers are symmetrically spaced so that the soundappears to come from points located along an axis passing from front to back through the center point ofthe enclosure. Applying recommended signal delay then unifies those points, making each module anapparent point source.

As enclosures are added to an array, these points then define a line source. Further, the box-to-boxtransducer spacing is close enough to promote physical coupling through the entire LF and much of theMF passband, even in flat-faced configurations.

Intelligent horn design facilitates box-to-box coupling through the upper MF and HF passbands.Engineers paid particular attention to the HF horns, designing them to produce arced, not flat, wavefrontsfor smoother response in single coverage as well as optimized coupling.

As stated above, all coupling features assume no gap between module faces.

Upfill

Many applications will require upfill coverage. Flown KF760 Series arrays can provide up to 12of upfillcoverage without additional rigging. Simply apply the basic array building techniques to up-angle KF760 sor KF761 s for coverage above the horizontal axis. Upfill for groundstacked applications is coveredseparately.

Horizontal Coverage and Side-fill Arrays

A KF760 Series array provides a horizontal coverage patternof approximately 80 for the KF760 s and 100 for theKF761 s, with pattern control maintained to a very lowfrequency regardless of the length of the array.

A KF760 array s horizontal coverage pattern features so-calledsoft shoulders (consistent frequency response to well beyondthe nominal 6 dB points) that greatly improve horizontal arrayintegration. These soft shoulders add up to 20to the effectivecoverage area, producing 120 of usable horizontalDispersion. This, in turn, greatly eases the implementation ofside-fill arrays. In some situations, the soft shoulders alonemay be sufficient.

KF760 Series Side-fill Arrays

Because of the well-controlled midrange, KF760 Series side fillarrays can be hung adjacent to the mains, extending thecoverage up to 160. If needed, use the soft shoulders of thearray to extend coverage to nearly 180 with excellentfrequency response and adequate level.


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KF750 Series Side-fill Arrays

Use vertical columns of KF750 Series enclosures as side-fill loudspeakers, angling the axis of the firstcolumn 60 from the axis of the mains. Assuming left-right symmetry, this extends system coverage toabout 75 to either side of the stage axis for a total of 150. An additional column on each side willextend coverage to 105 for a total of about 210. A typical arena will require a column that is three or fourenclosures high. The three-enclosure column would consist of 2x KF750 over 1x KF755. Wheresubstantial up-fill is required, the fourth enclosure would consist of 1x KF755, inverted, on top.

NOTES:1. Use the KF750 Wizard to determine the delay and shading settings required for the side-fill array.2. The overall level balance between the KF760 Series Arrays and the KF750 Side-fill Arrays can be

easily balance by ear. The sensitivities are close to equal so normally the same drive level from thesame processors will produce close to equal levels from each of the arrays.

Subwoofers

Although the impressive low frequency performance of KF760 Series arrays allows them to be usedwithout subwoofers for some events, subwoofers will normally be used for live musical performances.

EAW recommends using KF940 Super-Subs or the trusty SB1000e. In most arrays, use one SB1000e per KF760 up to 16 subwoofers one SB1000e per pair of KF761 s when KF761 s are used alone one KF940 per three KF760 s, up to 16 subwoofers

Of course, if your program material demands additional sub bass response, employ additionalsubwoofers as needed.

3 Power and Processing

Amplifier Set Up

As is true of all professional loudspeaker systems, the performance of the KF760s and KF761s dependson amplifiers delivering an adequate supply of clean power.

The selection of the appropriate power amplifier is a subject of some debate. For more information onselecting the right amplifier for a given loudspeaker system, please consult EAW s Technical PaperPower Handling and Amplifier Selection.

In order for Divergence Shading to work properly, users must set all amplifiers for all passbands to thesame voltage gain, regardless of their power output ratings.

Note: This does NOT mean the same input sensitivity, but the same input to output voltage gain. Consult your amplifier manufacturer if this cannot be readily determined.

Do not boost or attenuate response at the amplifiers; rather, adjust the curvature of the array asdescribed above. This will maintain coherent response throughout the venue.

Input Connectors

The connections for the KF760 and KF761 are identical, both using Neutrik NL8MP input connectors.

Input Connector Pin-Outs

ModelLF 1

(left looking from rear)LF 2

(right looking from rear) MF Pins HF PinsKF760 1- / 1+ 2- / 2+ 3- / 3+ 4- / 4+KF761 1- / 1+ 2- / 2+ 3- / 3+ 4- / 4+


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Note: Each of the two LF transducers has its own input connections.

Signal Processing

The signal processing adjustments determined by EAW for the KF760 Series Array should be fullyimplemented as is. These settings are determined from extensive measurements in typical venues aswell as the theory of curved sources from the acoustical work of physicists Harry Olsen and Leo Beranak.As such, they will normally provide excellent results in a variety of venues.

Normally only 1/3 octave equalization should be required to modify the performance for a particular venueand/or type of program material. If multiple processors are used, it is recommended that a 1/3-octaveequalizer be used in line with the KF760 s and another with the KF761 s. This way, the longer and shorterthrow characteristics of the array can be individually modified as needed.

Signal Block Diagram

The following block diagram shows the required signal flow for a large KF760 Series line array. Forsmaller venues, reduce this setup by eliminating (in this order) the long throw section, the medium throwsection, the short throw section, ultimately leaving a near-field array comprised only of KF761 s. Note thatthe minimum array comprises four enclosures. Subwoofers, as always, are optional depending onprogram needs.

Signal Processor Settings

6 KF760 / 2 KF761 / KF940

SUB (KF940)GAIN 8dBDELAY 5msecPEQ1 99.2Hz -8dB Q = 2.0 ParametricPEQ2 66.2Hz -8dB Q = 4.0 ParametricHPF 27.8Hz 24dB Linkwitz-RileyLPF 74.3Hz 24dB Linkwitz-Riley

Subwoofers

To KF761 LF Amplifiers

To KF761 MF Amplifiers

To KF761 HF Amplifiers

To KF760 LF Amplifiers

To KF760 MF Amplifiers

To KF760 HF Amplifiers(short/medium throw section

To KF760 HF Amplifiers(long throw section)

PEQ Gain

Gain

Gain

PEQ

PEQ

Delay

Delay

Lim/Comp

Lim/Comp

Lim/Comp

PEQ Gain

Gain

Gain

PEQ

PEQ Delay

Delay Lim/Comp

Lim/Comp

Lim/Comp

PEQ Gain Lim/Comp

8-wayCrossover(This may

consist of oneor more

processors)

HPF LPF Lim/CompGain Delay

HPF LPF

HPF LPF

HPF LPF

HPF LPF

HPF LPF

HPF LPF

HPF LPF

Delay

Delay

PEQ

Delay

User EQ1/3

Octave


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INPUT (6 x KF760)GAIN 0dBDELAY 20msecPEQ1 364Hz -4dB Q = 1.5 Parametric

LF (6 x KF760)GAIN -5.5dBDELAY 0.00msecPEQ1 54.1Hz +6dB Q = 1.6 ParametricPEQ2 118Hz -5dB Q = 2.5 ParametricPEQ3 236Hz -9dB Q = 2.2 ParametricPEQ4 167Hz +6dB Q = 2.1 ParametricHPF 76.5Hz 24dB ButterworthLPF 172Hz 24dB Butterworth

MF (6 x KF760)GAIN -13.5dBDELAY 2.71msecPEQ1 273Hz +3dB Q = 2.0 ParametricPEQ2 408Hz -1.5dB Q = 2.8 ParametricPEQ3 841Hz -4dB Q = 2.7 ParametricPEQ4 1189Hz -1dB Q = 2.0 ParametricHPF 193Hz 24dB ButterworthLPF 1335Hz 24dB Butterworth

HF (6 x KF760)GAIN -6dBDELAY 3.10msecPEQ1 1682Hz -11.5dB Q = 2.7 ParametricPEQ2 3175Hz -5dB Q = 2.4 ParametricPEQ3 5496Hz -3dB Q = 3.4 ParametricPEQ4 16469Hz +9dB Q = 1.3 ParametricPEQ5 595Hz -10dB Q = 4.0 ParametricHPF 1059Hz 24dB ButterworthLPF 21983Hz 12dB Bessel

LF (2 x KF761)GAIN -5.5dBDELAY 0.00msecPEQ1 54.1Hz +6dB Q = 1.6 ParametricPEQ2 118Hz -5dB Q = 2.5 ParametricPEQ3 236Hz -9dB Q = 2.2 ParametricPEQ4 167Hz +6dB Q = 2.1 ParametricHPF 76.5Hz 24dB ButterworthLPF 172Hz 24dB Butterworth

MF (2 x KF761)GAIN -13.5dBDELAY 4.06msecPEQ1 273Hz +2dB Q = 3.4 ParametricPEQ2 944Hz +3.5dB Q = 2.1 ParametricPEQ3 1414Hz +2.6dB Q = 1.5 ParametricPEQ4 612Hz -1dB Q = 3.6 ParametricHPF 198Hz 24dB ButterworthLPF 1634Hz 24dB Butterworth


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HF (2 x KF761)GAIN -7dBDELAY 2.60msecPEQ1 612Hz -5dB Q = 2.0 ParametricPEQ2 2059Hz -11.5dB Q = 1.1 ParametricPEQ3 5496Hz -5dB Q = 1.7 ParametricPEQ4 10679Hz +8dB Q = 1.5 ParametricPEQ5 3175Hz +0.5dB Q = 3.0 ParametricHPF 1297Hz 24dB ButterworthLPF 19027 12dB Bessel

4 Rigging and Transportation

WARNING: Suspending anything, especially overhead of people, should be done withextreme caution. Always engage the services of a certified professional who is qualified todetermine the requirements for and to implement overhead rigging.

The KF760 Series features a simple, elegant rigging system that enables a crew of two people to flyarena-sized arrays in a matter of minutes. Connecting pins stay with the enclosure rigging, recessedwithin the enclosure envelope, eliminating loose pieces that can get lost or damaged.

The complete rigging system includes:

KF760 Caster Pallet: The caster pallet designed for the KF760 can normally transport a stack of up tofour enclosures. The pallet automatically provides a staging platform for any array to add or remove apre-rigged assembly of up to four enclosures at one time. It also serves as a rigging aid to mountKF761 s to an array.

KF761 Caster Pallet: The caster pallet designed for the KF761 Series is for transporting a single KF761enclosure. Normally the KF761 is transferred to a KF760 pallet for rigging to the array.

KF760 Series Fly-Bar: The fly-bar designed by EAW specifically for the KF760 Series, is modularallowing considerable versatility for flying a KF760 Series array. The fly-bar can be set up in severaldifferent configurations depending on the particular rigging situation and/or pullback requirements. Thefly-bar is made of heat-treated, structural steel with a working load capacity well in excess of typical arrayrequirements.

Pull-Back Bar: This piece attaches to the bottom rear of the bottommost enclosure in the array. This isused as the attachment point for a pull-back motor to tilt the array by pulling up from the bottom rear ofthe array.

Tail-Piece: This piece attaches to the center of the Fly-Bar Spreader. This is used as the attachmentpoint for a pull-back motor to tilt the array by pulling up from the top rear of the array.


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KF760 SERIES FLY-BAR

Enclosure to Enclosure Connections

Three splay angles have been engineered into each KF760 Series models: 0, 1.5 or 3 for the KF760 and0, 4, 8 or 12 for the KF761. Splay angle is set at the rear of the enclosures rather than the front,leaving the fronts of all enclosures tight-packed.

A captured hinge on top of the lower enclosure slides freely in the steel tube on the bottom of the upperenclosure (or Fly-Bar). Load-rated, aircraft-grade aluminum quick-release pins then fit through preciselylocated holes to lock the hinge in the tube.

The KF760 Wizard will specify the proper connecting holes to use on each enclosure in order to achievethe required face-to-face angles. Remember that these refer to holes at the rear of the enclosure. Alwayskeep the fronts of the enclosures tight-packed.

ENCLOSURE RIGGING HARDWARE


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Rigging Load Rating

The KF760 Series Fly-Bar can safely suspend arrays comprising any combination of up to 20 KF760Series array enclosures. The design factor for the above rating is 8-to-1. Certified pull-test results for theEAW-supplied rigging system are available from EAW upon request.

WARNING: The Design Factor listed is only for the KF760 Series enclosures and Fly-BarSystem. It is the responsibility of the user to ensure that any attachments to the Fly-Barand to building architecture, as well as any other external rigging components andhardware are appropriately load-rated for the intended use.

WARNING: The Design Factor listed is only for a vertical pull, 5, (10 with a pull-back),on the enclosure rigging and KF760 Series Fly-Bar System. This is the intended riggingmethod. EAW cannot be held responsible for any consequences arising from using theKF760 rigging components in other than the intended method.

Important Rigging Factors

The Fly-Bar must be suspended from supporting structure using a minimum of two pick points, oneeach for the hoisting ring on each rigging bar.

Without a pull-back, the pull on the fly-bar must be within 5 of level from front-to-back. Where the Fly-Bar angle must be in excess of 5 from level front-to-back to achieve the desired

coverage, an additional pick point and the Tail-Piece or Pull-Back Bar must be used as a pull-backsystem.

The Fly-Bar must always be level side-to-side. All four suspension points between an enclosure and the Fly-Bar and between any two enclosures

must be fully engaged and locked into position using the appropriate connecting pins.

Final Adjustments to the Flown Array

Two important criteria must be evaluated for the final physical adjustments to the flown array. An accurateassessment is crucial to aim the array.

1. The top of the array must be set so that the furthest and/or top row of seating can barely see thetop surface of the top enclosure. If the top surface can be readily seen, that location is out of thedispersion pattern. Even a slight change in angle of a couple of degrees can miss the desiredcoverage area. If a pull-back is used for the array, it should be set with this in mind.

2. The same is true for the bottom of the array. Because of the tight pattern control, the bottomKF761 or KF760 must be angled to properly cover near the stage. The nearest listener shouldbarely be able to see the bottom surface of the bottom enclosure. If a pull-back is used for thearray, it should be set with this in mind.

KF760 Coverage Wizard

The KF760 Wizard is a tool for physically configuring a KF760 Series Line array. It determines the bestconfiguration for a given quantity of KF760 s and/or KF761 s in a given venue. This Wizard requires theuser to enter various venue dimensions in order to calculate the desired array performance andrecommend the configuration that will provide the best vertical coverage. The Wizard will not select theoptimum number of enclosures, but will calculate the optimum enclosure splays, array aiming angles, andFly-Bar pick point for a given quantity of KF760 s and/or KF761 s.


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Wizard Results

The results in the Wizard show: Graphical representations of the array and the venue. Axial splay angle between each pair of enclosures. Note this is NOT the rear splay angle but the

angle between the aiming axes of the enclosures. On-axis aiming angle for each enclosure as a difference from 0 horizontal. A positive angle is

above horizontal and a negative one is below horizontal. Various angles and throw distances calculated from the venue s dimensions. Difference between the array dispersion angle and the needed coverage angles. Length of the array and trim height to the bottom of the array from the floor. Weight of the array. Pick Point on the Fly-Bar to achieve the calculated array angle when suspended. This is

calculated from the centers of gravity of the enclosures and the Fly-Bar. An adjustment angle for tilting the entire array to equalize the difference in the top and bottom

dispersion angles versus the needed coverage angles.

Transport

The KF760 Series is designed for easy transportability, not only by itself, butas part of the typical compliment of touring road cases and other equipment.

The optional KF760 Caster Pallet is exactly 45-in wide, the same width as astandard road case, and can support up to four KF760 s. Integrated rigginghardware locks the enclosures together and to the Caster Pallet, leaving thetopmost enclosure surface flat to accept decking for a second level ofequipment.

The KF761 pallet supports a single KF761.

WARNING: In no case should more than four enclosures beplaced on a KF760 Series Caster Pallet. Doing so can create anunstable stack that could fall over causing property damage,physical injury, or death.

Truck Packing

The KF760 Series was carefully dimensioned to easily fit several ways in conventional commercial trucks.The enclosures are normally loaded two wide in the truck, riding up to four high on KF760 Series CasterPallets. However, because of the 31-in depth, they can also be turned 90 and loaded three wide in mosttrucks. Typical truck dimensions are given in the following table.

TRUCK INTERNAL WIDTH PACKINGStandard North American drop-frame semi-trailers 91" 2 pallets wideStandard European drop-frame lorry trailers 91 2 pallets wideSea containers standard High Cube 92.5" 2 pallets wideSmaller trucks such as 24 ft Ryder-type rental boxes 95" 2 or 3 pallets wideMaxi-size European drop-frame lorry trailers 98" 2 or 3 pallets wideStandard North American flat-floor semi-trailers 99.5" 2 or 3 pallets wide


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112"32"

71"

37"

90"

TRUCK PACKING FOR 12 KF760 AND 6 KF761

KF760 Touring Usage Guide

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