EAW | Loudspeaker's | The Forsythe Series KF550 is a high defini- tion sound

The Forsythe Series KF550 is a high definition sound reinforcement loudspeaker system
designed for high output sound reinforcement
applications. Its "One Box" design permits ease
transport and idealized driver alignment and
subassembly integration resulting in maximally
flat frequency and phase response. The use of
complex subassemblies provides full horn
loading over its entire operating range for
precise control of coverage and directivity.
The KF550's advanced technology is e
direct result of EAW's unmatched expertise in
"One Box" system design and construction;
after all, EN invented the "One Box" horn
loaded system. By working closely with the
leading sound rental companies throughout
the world, we designed the KF550 for the way
you use professional loudspeakers. You'll find
that its features will make your operation
more efficient and cost effective.
We invite you to compare other systems
and see the performance and features that
set the KF550 apart from all other high
output loudspeaker systems.
We're confident you'll choose the
KF550 "One Box System That Defies
Advanced Designed Horn Subassemblies
The Forsythe designed mid and bass horn subassemblies
utilized in the KF550 are the most sophisticated on the
market. They were developed from advanced computer
optimized mathematical models and then are
precisely created with a proprietary polyurethane reinorced
wood construction technique. The final designs are tested for
both acoustical and mechanical performance and any
necessary upgrades are made to the design. Unlike competitive
systems that, at best, approximate a true horn., the KF550's true
mathematical correct horns provide exceptionally smooth air
loaded impedance characteristics. The finished product results
in fidelity that is not only significantly better than any other horn
system but surpasses most vented systems, and unprecedented
output capabilities.
Industry Standard Mid Range Definition
The mid range subassembly in the KF550 is adapted from
EAW's legendary MR-102, the world's most popular horn
loaded mid-bass system. EAW has produced thousands sands
of these mid-bass horns, and they are in daily use in some of
the most demanding professional applications from the
Palladium in New York to the Sun PIaza in Tokyo. The MR102
ior performance. This device eliminates the power response
irregularities that plague all competitive midbass horns by
maintaining proper loading from the mouth right down into
the throat. The result is smooth frequency response on and
off axis, so the sound character of the KF550 is identical
anywhere in its coverage area.
Constant Coverage High Frequency
The KF550C's high frequency subassembly is the new RCF
H9040 horn which offers constant coverage over its entire
operating band` The horn flare configuration has been
maximized to achieve constant coverage without the increased
distortion of competitive designs. To ensure high mechanical
strength and total freedom from resonances, the horn is
constructed of high pressure die cast aluminum alloy with a
minimum thickness of 4 mm.
The H9040's throat accepts all standard two-inch exit
drivers. The TAD 4001 is recommended for use when
extended high frequency performance is required. The JBL
2445 can also be used for less demanding applications.
Efficient Interface to Amplifiers West Signals
The KF550C includes as standard a unique input
arrangement, including a hinged door that reveals a cable
transport compartment with a recessed input termination
panel and wiring barrier strip. The input termination panel
includes two parallel EP Series 8 pin connectors and banana
type test points for each driver in the system. The test points
enable easy testing of individual drivers without the need for
special cabling.
Reliability: The Industry Standard
Constructed from imported 18 ply to the inch cross
grain laminated hardwood with all horn flare reinforced with
high density polyurethane foam, the KF550 utilizes the
technology that has made EAW the world's leading supplier
of high output systems for portable applications. Other
standard KF550 features include black catalyzed polyurethane
chemical coating finish, recessed rattle free metal handles,
slant back with heavy duty castors and vinyl coated
perforated steel speaker grills.
The KF550: Reliability, Performance, Quality, In
The Engineering Advantage
When you consider the fact that EAW
builds the KF550 it should come as no sur
prise that it is the qualitative standard of the
industry. After all, EAW's director of engi
neering, Kenton Forsythe, has spent the last
twenty years advancing the "state of the art"
in concert sound loudspeaker systems. His
contributions to the industry include:
Forsythe B215, the world's first 2 x 15 inch bass
horn to incorporate a phase coupler and true
exponential flare (not to mention that it fit
through most doors).
1976 Forsythe SR1 09, the world's first cone mid range
horn utilizing a phasing plug and lead reinforced
fiberglass construction.
1977 Forsythe B212CT, using polyurethane filled
subassemblies to create the world's most
mathematically correct bass horn.
1978 EAW MR102, the first mid bass horn to use a
center displacement plug for flat power response.
1978 EAW/Carlo CS3, the world's first "One Box"
horn loaded flying system.
1979 EAW BH800, the first bent horn using
polyurethane reinforced wood construction.
1981 EAW JF500, the world's first all horn loaded
compact full range system.
1983 EAW KF550, the world standard "One Box" flying
system with flying strip hardware enabling easy
construction of complex arrays with only two fly
points per cabinet.
Since then we have continually refined
the KF550 to stay well ahead of our imitators.
The new KF550C version adds the H9040
constant coverage high frequency horn, full
frontal coverage vinyl coated perforated steel
grills and rear panel cable/connector chamber
as standard. This is in addition to the standard
features and performance that has made the
KF550 the first choice of sound companies in
the past.
Your crews will love the KF550C
because it loads in and flies so easily, and your
accountant will appreciate its transport
efficiency. But we're confident that you will
choose the KF550C because it sounds great.
Acoustical System Performance
Frequency Response
- 10 dB:
+- 3 dB:
Coverage Angle (-6dB)
Axial Sensitivity
HF Subassembly:
MF Subassembly:
LF Subassembly:
Power Handling
HF Subassembly:
MF Subassembly:
LF Subassembly:
Maximum SPL at I meter
At 10k Hz:
At 1k Hz:
At 100 Hz:
Nominal Impedance
LF Horn
Quad Array
Single Unit
35 Hz to 20,000 Hz
42 Hz to 20,000 Hz
45 Hz to 18,000 Hz
55 Hz to 18,000 Hz
Horizontal: 80 degrees; Vertical: 40 degrees
112 dB SPL I w @ I in
109 dB SPL 1 w @ I m
109 dB SPL 1w @ 1m
70w 100 Hour Sine Wave
200w AES
150w 100 Hour Sine Wave
375w AES
500w 100 Hour Sine Wave
1000w AES
Long Term
130.5 dB SPL @ 70w
135 dB SPL @ 200w
130.5 dB SPL @ 150w
134.5 dB SPL @375w
136 dB SPL @ 500w
139 dB SPL @ 1000w
HF Subassembly
MF Subassembly
LF Subassembly
Subassembly 16Q
Forsythe Designed Bent Bass Horn
Cross-Grain Laminated Birch Plywood With High Density
Polyurethane Foam Reinforcing
Two RCF Laboratory Series L15/554K
380 mm 0 5-in) Cone Driver With
100 mm (4-in) Voice Coil
MF Horn Subassembly
Forsythe Designed Constant Coverage Horn Incorporating Center
Displacement Plug
Cross-Grain Laminated Birch Plywood With High Density
Polyurethane Foam Reinforcing And Cast Polyurethane
Phasing/ Displacement Plug
RCF Laboratory Series Ll 2 / P1 I W
300 mm (12-in) Cone Driver With
100 mm (4-in) Voice Coil
HF Horn Subassembly
RCF H9040 Constant Coverage Horn
High Pressure Die Cast Aluminum Alloy
User Supplied TAD 4001 (JBL 2445 can be used for applications
where extended high frequency response is not required)
Additional Descriptive Data
Protective Grill:
Black Polyurethane Chemical Coating
Input Panel Located In Rear Cable Transport Compartment Includes
Dual Canon EP-8 Males Plus Individual Banana Plug Test Points On
Each Driver. All Connectors Are Wired To Internal Barrier Strip
That In Turn Is Connected To The Drivers For Easy Field
Reconfiguration Of The EP-8 Pins.
Four Multi-Locking Point Strip Type Aircraft Fittings At The Top
And Bottom Of The KF550's Side Panels, And Two Matting Clip
Lock Points Included As Standard.
Slant Back With Two Heavy Duty Castors For Simple Tilt And
Roll Transport
Heavy Gauge Vinyl Coated Perforated Steel Grill Screens Covering
The Entire Front Of The Cabinet
32.5 in x 53.75 in x 29.75 in
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