EAW KF750 Series Parts list manual

The Laws of Physics | The Art of Listening
EAW’s KF700 Series
Touring Usage Guide

Since its inception, EAW has combined market feedback with top-level engineering to
prod ce a range of tility-driven tools that address the needs of the to ring so nd market.
Over the last few years, EAW Engineering has worked steadily to find techniq es that allow
typical sers to create lo dspeaker arrays that act as a single nit. Developing and
integrating the vario s lo dspeaker mod les in the KF850, KF860 and KF900 Series has
led s to new ways of looking at array b ilding that provide even coverage thro gho t
large ven es.
These years of R & D have res lted in the logical, step-by-step array-b ilding process
contained within this G ide. While we foc s here on KF700 Series arrays, the basic
approach applies to these other EAW array-oriented prod cts.
1
EAW’s KF700 Series
Touring Usage Guide

2 DETERMINE HORIZONTAL COVERAGE
The horizontal coverage angle of any ven e can be
readily determined thro gh inspection of its plan view.
Once the horizontal coverage req irement has been
determined, calc late the n mber of col mns
req ired to thoro ghly address the entire
ven e based on each col mn's horizontal
coverage pattern.
I – The Five Basic Steps of Array Building
Ven e sizes and styles vary dramatically. It is not ncommon for a concert to r to play a 1,000 seat cl b, a 3,000
seat theater and an 8,000 seat arena on s ccessive nights. Creating the right array for each ven e is vital to
maintaining consistency and establishing a tr e contin m of s ccess. O r experience has led s to develop
a five step approach to designing the appropriate array for any ven e.
1 DESIGN ARRAY COLUMNS
Design a single array col mn that will address each vertical a dience zone in a cross-section r nning from the stage
thro gh the center of the ven e to the rear-most seat. Be s re to factor in the array trim height. To seamlessly cover
each vertical zone (front, middle, rear, balcony, etc.) req ires that the system engineer properly apply the vario s
array mod les in his/her arsenal incl ding s bwoofers. This is the primary key to delivering a niform response to
the entire ven e.
2
alcony
Design an Array Column
Main Seating
Downfill
Subwoofers
Right & Left Clusters
5x 30° Module Each
Provide 150° Coverage
Seats Not Sold
Seats Not Sold
STAGE
150°150°
Determine Horizontal Coverage

3
3 IMPLEMENT SIGNAL PROCESSING
Mod le-specific array processing, c rrently s pported by most digital platforms, allows the ser to address coverage
of each vertical a dience zone independently (i.e. separate settings for long throw, main coverage and downfill
array mod les). This s ally does not req ire a separate processor channel for each row.
10x KF755 (inverted)
2 Processor Outputs* for upfill KF755's
20x KF750
3 Processor Outputs for main coverage KF750's
5x KF755
2 Processor Outputs for downfill KF755's
Independent Powering Capability per Row
(Seven Total Processor Outputs Control 35 Modules)
Powering and Processing for a Large KF700 Series Array
4 APPLY ARRAY SHADING (AS3D™)
AS3D array shading is a techniq e EAW Engineering developed to minimize destr ctive interaction between array
mod les and prod ce even coverage in three-space (three dimensions). AS3D req ires that the array amplification
be zoned in horizontal rows to permit implementation of s btle bandwidth and row dependent amplifier adj st-
ments. Array shading has a dramatic impact on the consistency of tonality thro gho t the ven e.
5 TWEAK
That is, adj st EQ to s it yo r taste. The first fo r steps of array b ilding sho ld provide the ser with niform
coverage thro gho t the ven e s ch that he can set EQ at the mix position with f ll confidence that each
adj stment has the same impact thro gho t the ven e.
Tweak with Confidence
The mix heard at FOH
is the mix everybody in the venue will hear
* Optimally, each row should see two separate processor outputs,but
the only difference between the settings would be a subtle,but impor-
tant,change in the signal delay. This can more cost-effectively be
achieved by splitting the outputs of a single processor and routing one
pair through an external delay.

4
II – KF700 Series Array Philosophy
Since we set o t to develop the KF700 Series for ease of se, we insisted that arrays designed to cover any ven e
co ld be flown q ickly, easily, and safely as a dead h ng cl ster. S ch a system wo ld save the ser both time and
money while providing his/her client with an aco stically consistent and aesthetically pleasing cl ster.
To f rther enhance tility, the KF700 Series ses a m lti-axial approach that creates compact mod les that provide
the high “Q” pattern control associated with m ch larger devices. Combined with the tightly packed, dead-h ng
nat re of the cl ster, this allows for maxim m co pling of array elements, providing tremendo s o tp t capability
thro gh the low and mid freq ency s bsections of the array.
Finally, KF700 Series arrays will provide niform coverage with relatively simplistic processing. We have developed
AS3D array shading to enhance array control and coverage witho t req iring additional DSP nits.
THE GOLDEN RULES
Both o r experience and ser feedback has led s to develop two Golden R les for KF700 Series sage. Following
these r les will not g arantee s ccess. However, not following them will definitely compromise array performance.
1 Never let an a dience member see a handle on a mod le in their primary cl ster. (It is alright if someone seated
ho se-right sees a handle on the ho se-left cl ster). The KF700 Series lo dspeakers provide a 30∞horizontal pat-
tern that drops off very rapidly o tside of this nominal angle. Since the physical angle of the enclos re is also 30∞,
if yo can see the handle, yo are o t of the pattern. The difference in performance will be a dible.
Provide separate processing for each row of KF755’s. Using m ltiple rows of KF755’s allows KF700 Series arrays to
work in a n mber of challenging ven es, b t each row of KF755's m st be processed independently in order to
achieve proper integration. (N. B. This req ires only two channels of o tp t per row in large arrays in which the
KF750's alone prod ce s fficient LF response.)
III – Building Arrays:Bandwidth by Bandwidth
The soon-to-be-released KF700 Series Owner’s
Man al provides information regarding the f nda-
mental design attrib tes of the mod les within the
series. These systems are designed to exhibit pre-
dictable behavior when arrayed, b t it is important to
realize that array behavior is not the same as mod le
behavior. In fact, when arrayed, the individ al
devices within a mod le combine with their co nter-
parts in adjacent mod les to achieve a different level
of performance that m st be addressed as a system. It
is vital to nderstand the nat re of this device cooper-
ation in order to consistently b ild and ltimately
t ne these high performance cl sters.
Distributed HF Horns MF Line Source LF Line Array

5
Multiple MF Arrivals
Multiple HF Arrivals Create
Too Much Low HF (1 – 2 kHz)
Array Performance Issues Addressed by andwidth
Too Much Low Mid (300 – 600 Hz)
Weak HF Response
LOW FREQUENCY LINE ARRAYS
The low freq ency components within an individ al KF750 array mod le behave as a t ned dipolar array, b t in a
large format cl ster the low freq ency devices co ple to behave as a line array (a col mn of closely spaced devices).
These LF line arrays provide tremendo s o tp t along the primary axis of a dead h ng cl ster, and their coverage
pattern mimics the conto rs of most ven es. As a res lt, the LF s bsection req ires little adj stment except incre-
mental level atten ation as additional mod les are employed.
MID FREQUENCY LINE SOURCES
The mid freq ency horn in a KF700 Series mod le occ pies the f ll frontal dimensions of the enclos re. As a res lt,
adjacent mod les (incl ding KF755’s) co ple to behave as a tr e line so rce that exhibits increased directivity with
increased size, providing high levels of pattern control thro gho t the operating bandwidth. Projection of lower
mid freq ency information is also improved to the point that low/mid energy in the long throw may need to be
atten ated to provide more spatial consistency.
The imp lse response of a line so rce is most notably infl enced by the edge events. That is, an imp lse response
meas rement reveals two distinct pper mid freq ency arrivals coming from the physical edges of the line so rce
(i.e. the top of the top mod le and the bottom of the bottom mod le). Th s at an observation point beneath the
cl ster the first meas red arrival comes from the lower line so rce edge while the second, noticeably later, arrival
comes from the topmost edge. These m ltiple arrivals in t rn prod ce comb filtering in the front rows of a typical
ven e which, fort nately, can be eliminated with appropriate AS3D array shading .
HIGH FREQUENCY DISTRI UTED SOURCES
The high freq ency horns in a KF700 Series array are not prone to co pling as they are physically separated and
behave as distrib ted so rces m ch like the behavior of KF850 arrays.
When sing KF755’s as down/front fill lo dspeakers, the mix position is typically provided with high freq ency
o tp t from the KF755’s as well as m ltiple rows of KF750’s. If the arrivals from the KF755's and the next row of
KF750’s are near one another in level, the bottom of the high freq ency operating range becomes dominant at
front-of-ho se position. However, implementing appropriate AS3D array shading will eliminate this b ild p of
1kHz to 2kHz energy at FOH.
In long throw applications, the air's absorption of HF energy significantly impacts response as the distance from the
so rce increases. Techniq es will be disc ssed later in this G ide that allow the ser to address this specific iss e.

The Laws of Physics | The Art of Listening
EAW’s KF700 Series
Touring Usage Guide
INTEGRATING MODULES INTO AN ARRAY COLUMN

6
4.3' difference in throw results in 1.32 d less output in the nearfield
Add 1.32 d additional downfill gain to compensate for 5' increased trimheight
Adding downfill gain to compensate for additional trim height
26.3'
30.6'
20'
25'
12'
12'
1x KF755 (inverted)
4x KF750
1x KF755
1x KF755 (inverted)
4x KF750
1x KF755
0 d
-1.32 d
I – Using KF750’s for Primary Coverage
As disc ssed in Section 1, array col mns are created based on a ven e’s cross-section. Nat rally, the overall depth of
the ven e will govern the n mber of KF750’s in the col mn with larger ven es req iring more KF750’s per col mn.
For basic g idelines on the q antity of KF750’s req ired per col mn in specific ven e types, see Section 4.
II – Using KF755’s for Downfill Coverage
When cl sters are flown, most ven es req ire downfill in order to effectively cover the front of the a dience. Since
the KF755 ses an asymmetrical m lti-axial design, it will provide downfill coverage from a deadh ng array.
Properly integrating KF755 downfill mod les with appropriate processing and AS3D techniq es will provide even
coverage to the front of the ven e witho t creating interference iss es in the transition area between KF755 and
KF750 coverage.
Dedicated downfill mod le processor settings* allow sers to integrate KF755’s into a KF750 cl ster witho t
modifying the KF750 processing. The nconventional settings that res lt will make a KF755 so nd tonally
nbalanced when listened to in the absence of a KF750 array above. This is entirely intentional and provides
for tonally transparent transition from downfill coverage to the primary cl ster.
IIa – Adjusting KF755 System Gain and System Delay
As the ser moves from ven e to ven e, (s)he need adj st only two critical KF755 parameters: system gain and
system delay, both of which vary with trim height and n mber of KF750's per col mn.
Defa lt KF755 gains are set for given KF750 q antities in the standard array processing. This gain however, m st be
adj sted as trim height varies. If the cl ster is flown higher than the defa lt setting’s ass mptions, the KF755 gain
m st be increased to compensate for increased throw and vice versa.
* Processor settings will be released in text format as part of the Touring Usage Guide.

7
All defa lt delay settings are config red to allow sers to fine-t ne delay at FOH. Downfill delay and gain can be
simply adj sted and t ned by ear. Coherent s mmation is a very a dible phenomenon. Aco stical analysis
systems, s ch as SIA-SMAART, aid in the ability to fine t ne these parameters. If FOH location and trim height are
typical and appropriate processing is being tilized, then KF755 integration sho ld be as simple as powering p.
III – Using SB750’s
Virt ally all pro a dio applications req ire s b bass reinforcement and a ratio of at least one SB750 per every two
KF700 array mod les is the r le of th mb. The SB750 offers sers the flexibility of stacking s bwoofers on the
gro nd or flying them with the array. Users can insert flown s bs as rows above and/or below the main array, or in
col mns along the off-stage side of the main array. (Inserting flown s bwoofers directly withing the main array is
not recommended.) Each location has benefits and trade-offs. Most ven es req ire a combination of locations for
optimal performance. In all cases, the s bwoofers m st be timed for coherent arrival in order to achieve
appropriate s mmation thro gho t a ven e.
IIIa – Groundstacking SB750’s
Many sers will choose to se SB750’s in a traditional gro ndstacked config ration. In addition to providing even
s b bass coverage thro gho t a ven e, this techniq e also provides maxim m s b bass impact in the front rows,
a q ality many fans have come to expect in high-energy live m sic performances.
1.169 msec - 0.931 msec = 0.238 msec
Therefore add 0.238msec of additional downfill delay to compensate for 5' of increased trim height
Adding downfill delay to compensate for additional trim height
20'
0.931msec arrival differential at FOH
1.169msec arrival differential at FOH
25'
100'
1x KF755 (inverted)
4x KF750
1x KF755
1x KF755 (inverted)
4x KF750
1x KF755
Defa lt processor settings delay the KF755’s back to the aco stic origin of the KF750 col mn. As more KF750’s are
sed per cl ster, the apparent origin of the col mn moves pward and increased KF755 system delay is added with
each row of KF750’s.
Defa lt processor settings apply system delay to KF755 downfill mod les based pon ass med typical trim heights
and FOH locations as described in Section 4. If FOH is atypically close, this delay sho ld be increased. If FOH is
atypically distant, the system delay sho ld be red ced.

8
The SB750 has the same footprint as the other KF700 array mod les, creating attractive cl sters when all
lo dspeakers are gro ndstacked. It also feat res a stacking pad that keys into the enclos re above it, providing a
safer gro ndstacked config ration. All gro ndstacked mod les sho ld also be connected with fly hardware. So nd
system designers sho ld note that an SB750 meas res nearly 4-ft in height, so that most applications will only
allow a two-high stack of s bs on the deck.
IIIb – Flying SB750’s
Flying s bwoofers, while nconventional, offers the designer a variety of advantages. Sightlines to performers are
completely nobstr cted providing a better experience to more concert-goers. B t the greatest benefit of flying
SB750’s lies in the ability to create dipolar arrays† of s bwoofer devices, providing vertical pattern control within
the s bwoofer pass band. This added control increases projection and apparent impact at great distances.
Additional processing also allows for s bwoofer beam steering.
Unlike conventional gro nd stacked s bwoofers, flown s bwoofers lose the increased o tp t benefit provided
by co pling to the floor. This loss of overall o tp t co ld be a detriment if too few s bwoofers are tilized with
a given performer.
Since KF700 Series arrays are zoned in rows to allow for AS3D® implementation, flown SB750 mod les are most
effectively deployed in rows either above or below the array.
When m ltiple rows of SB750’s are placed at the top of an array, they provide significant s bwoofer projection
and good overall vertical coverage b t lack the near field impact associated with gro nd-stacked s bwoofers.
This config ration req ires additional stacked s bwoofers to provide the impact associated with near field seating,
b t the n mber of mod les on the deck is greatly red ced.
Subs flown above an array
3x KF750
2x S 750
1x S 750
1x KF755
†For more information on Dipolar Array Technology, isit the Technology Section of EAW's website:
www.eaw.com/pages/TechS pport/Technologies/NewConcepts/TDA.html

9
Flying s bwoofers at both the top and bottom of an array allows for the creation of a dipolar array, providing signif-
icant pattern control thro gh the s b bass passband. A dipolar array res lts when direct radiating devices are spaced
s ch that their center-to-center distance is eq ivalent to one half wavelength within the operating bandwidth.
Dipolar sub array
3x KF750
1x S 750
1x S 750
1x KF755
S b freq encies have very long wavelengths. As a res lt, dipolar s bwoofer arrays are not typically possible.
However, by flying SB750’s both at the top and the bottom of a KF700 Series array, dipolar array can be created,
providing pattern control as low as 40Hz.
This config ration is not generally recommended when more than fo r rows of KF700 Series mod les are being
sed in the f ll range array beca se the dipolar array grows too large and pattern control becomes excessive in the
pper s b bass range with prono nced lobes above and below the cl ster. This limits the ability to project s b
freq ency information pward to the far reaches of the ven e, significantly red ces the s bwoofer o tp t in the
front rows of the ven e and red ces gain before feedback from mics onstage.
When SB750’s are sed above and below fo r rows of KF700 mod les, the slight near field atten ation can be
addressed by adding delay to the bottom rows of SB750, in essence steering the s bwoofer lobe to the desired
location. In a small to medi m arena, 6.5msec of delay on the bottom row of SB750’s forces the greatest s bwoofer
o tp t to FOH while providing tremendo s impact in the near field and still covering the back of the ven e.
Subs flown below an array
3x KF750
2x S 750
1x KF755
M ltiple rows of SB750’s can also be flown from the bottom of the array. These s bwoofers provide both the
coverage and impact associated with gro nd stacking with minimal sightline interference. However, flying the
entire array o t to the desired height for optimal front fill coverage may place the rows of SB750’s too low for some
ven es and associated staging.

10
In some ven es a col mn of flown s bwoofers is appropriate. As stated previo sly, two-high flown s bwoofer
col mns are the same height as three-high KF700 array mod le col mns. These two-high s bwoofer col mns can
be sed in smaller ven es and flown on the offstage side of the cl ster, close to the ven e wall. This config ration
will provide similar performance to flown rows while once again maintaining clear sightlines. Again, SB750
col mns sho ld not be inserted between KF700 col mns.
Flying subs as a column
Offstage
S 750
S 750
KF700
Series
module
KF700
Series
module
KF700
Series
module
KF700
Series
module
KF700
Series
module
KF700
Series
module
Onstage
Dipolar sub array w/ beam steering
6.5 msec delay
on bottom row
3x KF750
1x S 750
1x S 750
1x KF755
IV – Using KF755’s for Upfill Coverage
Many larger ven es (medi m and large arenas) req ire pfill in order to reach the farthest seating. This seating not
only req ires increased o tp t to overcome inverse sq are loss relative to the cl ster, b t also req ires significant
high freq ency emphasis in order to overcome the atten ation ca sed by air absorption. KF755’s are designed s ch
that when inverted and processed independently as long throw elements, they meet both criteria.
It sho ld be noted that the KF755, tho gh commonly tho ght of as a dedicated downfill mod le, is a very high Q
device. It exhibits the same pattern control as a KF750, b t tilizes asymmetrical horns to project this coverage at
an angle relative to the front of the enclos re. Conseq ently, KF755’s can readily do ble as long throw elements.

11
M ch like the downfill processing, KF755 pfill processing allows for the integration of KF755’s into a KF750
cl ster witho t modifying the KF750 processing. Once again this res lts in some nconventional processing.
The main KF750 array provides more than adeq ate LF information and projection to the pper seating, and
the pfill merely provides the information that is missing. Therefore only two channels of processing are req ired
for optimal pfill integration. In defa lt pfill settings, the KF755 pfill mod les are high passed at 350Hz and
provided with high freq ency eq alization to co nteract air absorption in typical ven es.
In medi m (13,000 seat) arenas, a single row of inverted KF755’s is adeq ate to provide appropriate pfill
projection. In larger arenas (18,000+), two inverted rows are more appropriate to provide pfill at 300 feet.
In either case, the pfill mod les m st be delayed so as to s m with the energy from KF750 col mn.
2 rows of upfill KF755's
in a large arena
1.237 msec & 1.756 msec
delay differential
A
B
C
Arrival difference from A to – 1.237 msec
2x KF755 (inverted)
4x KF750
1x KF755
2x S 750 Arrival difference from A to C – 1.756 msec
1 row upfill KF755's in a medium arena
0.3 msec
arrival difference
1x KF755 (inverted)
4x KF750
1x KF755
2x S 750
Defa lt processor settings apply system delay to KF755 pfill mod les based pon ass med typical balcony
locations and throws as described in Section 4. Aco stical analysis systems, s ch as SIA-SMAART, aid in the ability
to fine t ne these parameters. If, however, balcony position and throw distances are typical and appropriate
processing is being tilized, then KF755 pfill integration sho ld be readily achieved thro gh the se of
defa lt settings.
Each row of inverted KF755’s req ires two processing o tp ts with each row seeing different delay settings so as
to s m coherently in the balcony. Th s two rows of inverted KF755’s req ire fo r processing o tp ts. However,
another approach eliminates two of the fo r.

The main pfill processing (crossovers, eq alization, device delay) is the same for each pfill row. Only the system
delay changes. As a res lt, two f lly processed o tp ts can be sed to t ne the pfill. These o tp ts wo ld then feed
a delay line providing fo r o tp ts: two with more delay for the top row, and two with less for the second row.
A delay nit m st be caref lly chosen s ch that the latency delay thro gh the nit does not exceed the desired
delay for the second row of pfill.
12
4 processor outputs
driving 2 rows
of upfill KF755's
In Digital
processor
with four
available outputs
2 processor outputs
driving 2 rows
of upfill KF755's
In
In
Digital
delay
with a
latency
less than
0.2 msec
Digital
processor
with two
available outputs

13
V – Determine Horizontal Coverage
This f ndamental step is act ally q ite simple. With the KF700 Series, this coverage m st be narrowed to the most
appropriate m ltiple of 30° (90°, 120°, 150°, etc.). Dividing this req ired coverage by 30° yields the req ired
n mber of array col mns.
When determining horizontal coverage, it is important to remember the “visible handle” r le of th mb. Beca se
the KF700 Series pattern edge exhibits dramatic atten ation, the cl sters can be flown m ch closer to on-stage
witho t the feedback problems associated with conventional arrays. This allows the mixer to take greater advantage
of the KF700 Series stereo separation. It is possible to observe stereophonic information while seated directly in
front of one of the primary cl sters.
30°
Out of
coverage pattern
One side shown for illustration purposes

The Laws of Physics | The Art of Listening
EAW’s KF700 Series
Touring Usage Guide
AS3D™ (ARRAY SHADING IN THREE DIMENSIONS)

14
INSTALLMENT 3: AS3D™ (ARRAY SHADING IN THREE DIMENSIONS)
1 – Overview
The primary goal of an arrayed lo dspeaker system is consistency. The FOH engineer needs to know with
confidence that the tonality present at the mix position is the same thro gho t the ven e. With any array of devices,
interactions are present that can create inconsistencies thro gho t a performance space. The KF700 Series was
designed to minimize these effects, b t also to isolate those that remain and develop simple tools that resolve
these iss es witho t the introd ction of complex processing. As disc ssed in Part 2 of this g ide, dedicated down
fill, primary, and p fill processing are the first steps in this optimization. AS3D™ array shading is the next.
– Vertical Array Shading
The key to consistency of coverage when dead hanging KF700 Series prod ct is zoning the array amplification
in rows. This allows the ser to adj st the gain for each row to optimize performance.
Vertical Array Shading in the Mid Frequencies
As disc ssed in Part 1, an array’s mid freq ency imp lse response is governed by two distinct arrivals that are
directly linked to the ends of the line so rce. If the array is short, these arrivals occ r close together. In larger arrays,
the arrivals are f rther apart.
These d al arrivals create problems in areas that lie off of the primary array axis (like the nearfield). In the far field
the arrivals s m coherently. In either case, atten ating the mid freq ency devices at the top of the cl ster softens
the second arrival, virt ally eliminating any harmf l interaction in the front of the ven e. Depending on the size
of the array, one or more rows of mid freq ency devices will be t rned down sing simple amplifier adj stments,
improving the consistency of mid freq ency coverage.
Figure 1 shows the
appropriate AS3D settings
for maximizing coherence
of this specific array which
we use to illustrate the
effecti eness of AS3D in
the remainder of this section.
Please note that the
addition of upfill rows does
not affect the primary and
downfill response.
Except for the downfill
delay,all these adjustments
can be implemented by
adjusting amplifiers that
ha e been zoned by rows.
AS3D™ for a 2 over 4 over 1 array
10x KF755 inverted
No adjustment
5x KF750
Mids -6 to -9 d
5x KF750
Mids -3 d
5x KF750
Highs -3 d
5x KF750
Highs -6 to -9 d
5x KF755
Highs & Mids
Appropriate downfill delay
Independent Powering Capability per Row

15
This simple techniq e provides the added benefit of softening the projection of the dominant low/mid lobe.
This spatial smoothing res lts from introd cing asymmetry to the mid freq ency line so rce drive signals.
As a res lt, the shading adj stment tempers the low/mid o tp t in the far field, providing extremely consistent
mid-range coverage thro gho t any ven e.
The dramatic impact of this array shading can be readily demonstrated by creating a model of array performance
sing EAW's Phased PointSo rce Technology optimization and modeling program, F-Chart*. These complex
freq ency response charts predict array performance at a variety of listening positions. For the sake of legibility,
only three locations are shown (0°, -10°, -20°). These locations are ill strated in Fig re 2.
Array Response Locations
At 0°, -10° and -20°, these are the listening locations used in our model
Please note that the data presented below are based on a comp ter model of how a line so rce behaves as described
in s ch aco stical texts as Beranek and Olsen. Before b ilding the f ll array model, EAW engineers created a
preliminary model of a single KF750 midrange device and then performed extensive meas rements of an act al
KF750 to confirm the model's acc racy. Th s while these graphs do not represent act al array meas rements, they
are based on meas red data.
Figure 2
* For more information of PPST, isit the following URL at our website:
http://www.eaw.com/pages/TechSupport/Technologies/NewConcepts/PPST.html

16
The first chart (Fig. 3), showing array performance with no processing or eq alization, predicts significant comb
filtering at most locations with the best s mmation at the far field. The next two charts (Figs. 4 and 5), show how
performance improves when the top row of KF750's is atten ated 9 dB and the next row down is atten ated 3 dB.
The final chart (Fig. 6), depicts final array performance when appropriate delay is added to the bottom row of
downfill KF755's. Note that overall o tp t decreases only marginally while overall performance improves
dramatically.
Vertical Array Shading in the High Frequencies
The high freq ency response at FOH is governed by both the KF755 and KF750 horn arrivals. For best performance,
the KF755 m st be allowed to dominate. By simply shading the KF750 high freq ency devices in the row above the
KF755’s, the b ild p of energy between 1kHz and 2kHz is eliminated as demonstrated in Fig re 7 below. Note that
this response is generated by the same comp ter model referenced above.
By implementing these simple techniq es, effective and extremely consistent array performance can be provided
sing the simple dead h ng array. These s btle adj stments are also achieved witho t a req irement for additional
processing. In fact, short of overall low freq ency level adj stment, KF700 Series arrays can be tilized and
optimized by making minor adj stments to a few amplifier channels night in and night o t in varying ven es.
20 100 1000 10000 20000
dB SPL
Frequency (Hz)
K
B
Array response without AS3D™
-40
-20
0
20
20 100 1000 10000 20000
dB SPL
Frequency (Hz)
K
B
Now we add 9 d attenuation on top row of KF750's...
-40
-20
0
20
AS3D™ array shading techniques and their effects
on the mid frequency response of a 4 over 1 KF700 Series array
-40
-20
0
20
20 100 1000 10000 20000
dB SPL
Frequency (Hz)
K
B
...and finally we add appropriate delay
on the bottom row of downfill KF755's.
20 100 1000 10000 20000
dB SPL
Frequency (Hz)
K
B
... plus 3 d attenuation on second row of KF750's...
-40
-20
0
20
0 degrees -10 degrees -20 degrees
(in the vertical plane)
Figure 4Figure 3
Figure 6Figure 5