L-Acoustics K2 User manual

K2/KS28
user manual (EN)

Document reference: K2/KS28 user manual (EN) version 3.0
Distribution date: March 7, 2017
© 2017 L-Acoustics. All rights reserved.
No part of this publication may be reproduced or transmitted in any
form or by any means without the express written consent of the
publisher.

Contents
Safety................................................................................................................................................................ 4
Instructions................................................................................................................................................4
Symbols................................................................................................................................................... 4
Welcome........................................................................................................................................................... 5
System components.............................................................................................................................................6
Loudspeaker cables...................................................................................................................................7
Technical description........................................................................................................................................... 8
K2 horizontal directivity settings................................................................................................................. 8
K1-SB applications.................................................................................................................................... 9
Loudspeaker congurations................................................................................................................................10
Line source.............................................................................................................................................10
Additional subwoofer system....................................................................................................................12
K1-SB...........................................................................................................................................12
KS28........................................................................................................................................... 16
Loudspeaker connection.................................................................................................................................... 18
Connectors............................................................................................................................................. 18
Connection to LA4X................................................................................................................................ 19
Connection to LA12X.............................................................................................................................. 19
Preset description..............................................................................................................................................21
Recommendation for speaker cables...................................................................................................................22
Specications................................................................................................................................................... 23
K2 specications.....................................................................................................................................23
K2 dimensions.............................................................................................................................. 24
K1-SB specications................................................................................................................................ 25
K1-SB dimensions..........................................................................................................................26
KS28 specications.................................................................................................................................27
KS28 dimensions.......................................................................................................................... 28
3

Safety
Safety
Instructions
Inspect the product before operation.
If any sign of defect or damage is detected, immediately withdraw the product from use for maintenance.
Never incorporate equipment or accessories not approved by L-Acoustics.
Read all the related PRODUCT INFORMATION documents shipped with the products before
exploiting the system.
Do not store the product on an unstable cart, stand, tripod, bracket, or table.
Beware of sound levels.
Do not stay within close proximity of loudspeakers in operation.
Loudspeaker systems are capable of producing very high sound pressure levels (SPL) which can instantaneously
lead to permanent hearing damage to performers, production crew and audience members. Hearing damage
can also occur at moderate level with prolonged exposure to sound.
Check the applicable laws and regulations relating to maximum sound levels and exposure times.
This system is intended for professional use.
Read the RIGGING MANUAL before installing the system.
Use the rigging accessories described in the rigging manual and follow the associated procedures.
Read the maintenance section of this document before servicing the product.
Do not expose the product to extreme conditions.
Do not expose the product to rain or sea spray.
Do not expose the product to moisture (mist, steam, humidity, condensation…) or excessive heat (direct sun,
radiator…) for a long period of time.
Contact L-Acoustics for advanced maintenance.
Any unauthorized maintenance operation will void the product warranty.
Symbols
The following symbols are used in this document:
This symbol indicates a potential risk of harm to an individual or damage to the product.
It can also notify the user about instructions that must be strictly followed to ensure safe installation or operation of
the product.
This symbol noties the user about instructions that must be strictly followed to ensure proper installation or
operation of the product.
This symbol noties the user about complementary information or optional instructions.
K2/KS28 user manual (EN) version 3.0 4

Welcome
Welcome
Thank you for purchasing the L-Acoustics K2.
This document contains essential information on using the system properly.
As part of a continuous evolution of techniques and standards, L-Acoustics reserves the right to
change the specications of its products and the content of its document without prior notice. Please
check www.l-acoustics.com on a regular basis to download the latest document and software updates.
K2 variable curvature WST line source
The K2 is the full range element of a WST® line source with variable curvature and adjustable horizontal directivity.
The K2 loudspeaker enclosure is based on a 3-way active design. It comprises 4 input sections: 2 LF and 1 MF at a
nominal impedance of 8 ohms, and 1 HF at a nominal impedance of 16 ohms. It features two 12" speakers and four
6.5", all direct-radiating neodymium speakers mounted in a bass-reex enclosure, and two 3" neodymium diaphragm
compression drivers coupled to individual DOSC® waveguides and adjustable directivity ns. The transducers are
implemented in a K-shape conguration. The cabinet is made of machined rst grade Baltic birch plywood (for top,
bottom and back panels) combined to die cast aluminum side panels to ensure maximum acoustical and mechanical
integrity while reducing weight to the minimum. A four-point rigging system is integrated into the cabinet.
The K2 enclosure operates over the nominal frequency range of 35 Hz to 20 kHz. Its LF contour can be reinforced
with the dedicated K1-SB extension and its bandwidth can be extended down to 25 Hz with the KS28 subwoofer. In
the horizontal plane, the directivity is adjustable down to 300 Hz, with two symmetric settings (70° or 110°) and two
asymmetric settings (90° as 35°/55° or 55°/35°).
The K2 rigging system allows vertical assembly of enclosures with various inter-element angles (up to 10°), constituting
a line array with variable curvature. The combination of the coplanar symmetry and the DOSC® waveguide in the HF
region ensure a perfect acoustic coupling between the elements of an array. The WST® (Wavefront Sculpture Technology)
criteria are fullled, so that such an array can be qualied as a true line source. Any WST® line source provides a smooth
tonal response and a coverage that is free of secondary lobes over the entire frequency range.
The K2 is driven and quad-amplied by the LA12X or LA4X controller with factory presets which ensure linearization,
protection, and optimization for the loudspeaker system.
5 K2/KS28 user manual (EN) version 3.0

System components
System components
Loudspeaker enclosures
K2 3-way full-range active WST enclosure
K1-SB K1 system subwoofer 2×15"
KS28 Flyable subwoofer 2 x 18''
Powering and driving system
LA4X / LA12X Amplied controller with DSP, preset library and networking capabilities
LA-RAK II Touring rack containing three LA12X, LA-POWER II for power distribution and LA-PANEL II for
audio and network distribution
Refer to the LA4X / LA12X user manual for operating instructions.
Loudspeaker cables
SP cables 4-point speakON loudspeaker cables (4mm² gauge)
SP cables come in four sizes: SP.7 (0.7m/2.3ft), SP5 (5m/16.4ft), SP10 (10 m/32.8ft) and
SP25 (25m/82ft)
SP-Y1 breakout cable for two passive enclosures (2.5mm² gauge) provided with a CC4FP adapter
4-point speakON to 2 × 2-point speakON
DO 8-point PA-COM loudspeaker cables (4mm² gauge)
DO cables come in three sizes: DO.7 (0.7m/2.3ft), DO10 (10m/32.8ft) and DO25
(25m/82ft)
DOSUB-LA8 breakout cable for four passive enclosures (4mm² gauge)
8-point PA-COM to 4 × 2-point speakON
Information about the connection of the enclosures to the LA ampliers is given in this
document.
Refer to the LA4X / LA12X user manual for detailed instructions about the whole cabling scheme, including
modulation cables and network.
Rigging elements
Rigging elements or procedures are not presented in this document.
Refer to the K2 rigging manual.
Software applications
Soundvision 3D acoustical and mechanical modeling software
LA Network Manager Software for remote control and monitoring of amplied controllers
Refer to the Soundvision help.
Refer to the LA Network Manager video tutorial.
K2/KS28 user manual (EN) version 3.0 6

System components
Loudspeaker cables
0.7 m / 5 m / 10 m / 25 m
CH(1)
CH(2)
1 m
SP.7 / SP5 / SP10 / SP25 SP-Y1
0.7 m / 10 m / 25 m
SPK1
SPK2
SPK3
SPK4
5 m
DO.7 / DO10 / DO25 DOSUB-LA8
7 K2/KS28 user manual (EN) version 3.0

Technical description
Technical description
K2 horizontal directivity settings
The K2 enclosure features an adjustable horizontal directivity system. Using the adjustable ns, horizontal directivity can
be adjusted with four different settings: 110° / 70° symmetric or 90° asymmetric (35°/55° or 55°/35°). A specic K2
preset must be used for each directivity setting.
Within a line source, different directivity settings can be combined to improve the coverage of the audience geometry.
K2/KS28 user manual (EN) version 3.0 8

Technical description
K1-SB applications
There are two distinct applications for K1-SB in a K2 system:
— As an LF extension in a line source for enhanced throw, using the [K1SB_X K2] preset with K2
— As a subwoofer for increased impact, using the [K1SB_60] preset
Both applications of K1-SB can be combined in the same conguration.
K1-SB as an LF extension in a line source K1-SB as a subwoofer
K2 LINE SOURCE /
K2/K1-SB LINE SOURCE
K2 LINE SOURCE /
K2/K1-SB LINE SOURCE
ENHANCED THROW INCREASED IMPACT
9 K2/KS28 user manual (EN) version 3.0

Loudspeaker congurations
Loudspeaker congurations
Line source
Deployed as a line source, the system operates over the nominal bandwidth of the K2 enclosure, with an adjustable
horizontal directivity.
Two congurations are possible:
— K2 line source
— K2/K1-SB line source: enhanced LF throw
The [K2 70], [K2 90] and [K2 110] presets allow for a reference frequency response in long throw applications. Each
preset is dedicated to a horizontal directivity setting.
By providing the K1-SB with the same frequency response as the K2 low section, the [K1SB_X K2] preset allows the K1-SB
enclosure to be used as an LF line source element, increasing the length of the sub-low line source.
The K2 enclosures are driven by the LA4X / LA12X amplied controllers.
The K1-SB enclosures are driven by the LA12X amplied controller.
Standalone K2 line source
[K2 70] / [K2 90] / [K2 110]
[PRESET]
Enclosure K2
Preset [K2 70] [K2 90] [K2 110]
Frequency range (-10 dB) 35 Hz - 20 kHz
K2/KS28 user manual (EN) version 3.0 10

Loudspeaker congurations
K2/K1-SB line source
[PRESET]
[K1SB_X K2]
[K2 70] / [K2 90] / [K2 110]
[PRESET]
Enclosure K2 K1-SB
Preset [K2 70] [K2 90] [K2 110] [K1SB_X K2]
Frequency range (-10 dB) 35 Hz- 20 kHz
Recommended ratio 3 K2 : 1 K1-SB
Minimum line length 12 K2 + 4 K1-SB
When using [K2] with [K1SB_X K2], do not add any delay value between the K2 and K1-SB elements of a same
line source.
11 K2/KS28 user manual (EN) version 3.0

Loudspeaker congurations
Additional subwoofer system
A K2 line source or a K2/K1-SB line source can be deployed with additional subwoofer enclosures to provide increased
sub-low resources to demanding applications.
Two subwoofer systems are available:
— K1-SB for increased LF contour
— KS28 for infra extension
The recommended ratio is 3 K2 for 2 subwoofers, whether using K1-SB subwoofers only, KS28 subwoofers only, or a
combination of both.
The [K1SB_60] and [KS28_60] presets provide the subwoofers with an upper frequency limit at 60 Hz for an optimal
frequency coupling with the line source.
The K1-SB and KS28 subwoofer enclosures are driven by the amplied controller.
K1-SB
The K1-SB provides an extension of the bandwidth in the low end, down to 30 Hz. Depending on the deployment, LF
rejection can be produced.
Three deployments are available in this conguration:
— K1-SB on top of the K2 line source
— K1-SB beside the K2 or K2/K1-SB line source : side LF rejection (polarized)
— K1-SB behind the K2 or K2/K1-SB line source : rear LF rejection (cardioid)
K2/KS28 user manual (EN) version 3.0 12

Loudspeaker congurations
Line source with K1-SB on top
[PRESET]
[K1SB_60]
K2 LINE SOURCE
Enclosure K2 K1-SB as subwoofer
Preset [K2 70][K2 90][K2 110] [K1SB_60]
Frequency range (-10 dB) 30 Hz - 20 kHz
Recommended ratio 3 K2 : 2 subwoofers
Maximum number line length 12 K2 + 4 K1-SB
Delay values
Do not forget to add the pre-alignment and geometric delays depending on the conguration.
Pre-alignment delays
[K2] + [K1SB_60] K2 = 6 ms K1-SB = 0 ms
13 K2/KS28 user manual (EN) version 3.0

Loudspeaker congurations
Line source with K1-SB beside
K2 LINE SOURCE /
K2/K1-SB LINE SOURCE
[PRESET]
[K1SB_60]
0.5 to 1 m
(1.5 to 3 ft)
Enclosure K2 K1-SB in line source K1-SB as subwoofer
Preset [K2 70][K2 90][K2 110] [K1SB_X K2] [K1SB_60]
Frequency range (-10 dB) 30 Hz - 20 kHz
Recommended ratio 3 K2 : 2 subwoofers
Recommended spacing
between side panels
Between 0.5 m (1.5 ft) and 1 m (3 ft)
Delay values
Do not forget to add the pre-alignment and geometric delays depending on the conguration.
When using [K2] with [K1SB_X K2], do not add any delay value between the K2 and K1-SB elements of a same
line source.
Pre-alignment delays
[K2] + [K1SB_60] K2 = 6 ms K1-SB = 0 ms
K2/KS28 user manual (EN) version 3.0 14

Loudspeaker congurations
Line source with K1-SB behind
[PRESET]
[K1SB_60]
K2 LINE SOURCE /
K2/K1-SB LINE SOURCE
1.5 to 2 m
(5 to 7 ft)
Enclosure K2 K1-SB in line source K1-SB as subwoofer
Preset [K2 70][K2 90][K2 110] [K1SB_X K2] [K1SB_60]
Frequency range (-10 dB) 30 Hz - 20 kHz
Recommended ratio 3 K2 : 2 subwoofers
Recommended spacing
between front faces
Between 1.5 m (5 ft) and 2 m (7 ft)
Delay values
Do not forget to add the pre-alignment and geometric delays depending on the conguration.
When using [K2] with [K1SB_X K2], do not add any delay value between the K2 and K1-SB elements of a same
line source.
Pre-alignment delays
[K2] + [K1SB_60] K2 = 6 ms K1-SB = 0 ms
Geometric delays
1.5 m (5 ft) Line source = 4.5 ms
2 m (7 ft) Line source = 6 ms
15 K2/KS28 user manual (EN) version 3.0

Loudspeaker congurations
KS28
The KS28 provides an extension of the bandwidth in the low end, down to 25 Hz.
Line source with KS28
[PRESET]
[KS28_60]
K2 LINE SOURCE /
K2/K1-SB LINE SOURCE
Enclosure K2 K1-SB in line
source
K1-SB as
subwoofer
KS28
Preset [K2 70][K2 90][K2 110] [K1SB_X] [K1SB_60] [KS28_60]
Frequency range (-10 dB) 25 Hz - 20 kHz
Recommended ratio 3 K2 : 2 subwoofers
Grouping subwoofers
Place the subwoofer enclosures side by side. If not possible, the maximum distance between two adjacent
acoustic centers must be 2.8m or 1.7m if the upper frequency limit of the subwoofer system is at 60Hz or
100Hz, respectively.
Use [xxxx_xx_C] on a reversed subwoofer in a cardioid conguration
The cardioid conguration consists in reversing 1 element in an array of 4 subwoofers.
Refer to the subwoofer user manual and to the Cardioid congurations technical bulletin.
K2/KS28 user manual (EN) version 3.0 16

Loudspeaker congurations
Delay values
Do not forget to add the pre-alignment and geometric delays depending on the conguration.
When using [K2] with [K1SB_X K2], do not add any delay value between the K2 and K1-SB elements of a same
line source.
Pre-alignment delays
[K2] + [KS28_60] K2 = 0 ms KS28 = 6 ms
[K2] + [KS28_60_C] K2 = 0 ms KS28 = 0.5 ms
[K2] + [K1SB_60] +
[KS28_60]
K2 = 8 ms K1-SB = 2 ms KS28 = 0 ms
[K2] + [K1SB_60] +
[KS28_60_C]
K2 = 13.5 ms K1-SB = 7.5 ms KS28 = 0 ms
17 K2/KS28 user manual (EN) version 3.0

Loudspeaker connection
Loudspeaker connection
Connectors
The K2 is equipped with two 8-point PA-COM connectors.
K2
IN
LINK
Internal pinout for L-Acoustics 3-way active enclosures
PA-COM points A/B C/D E/F G/H
Transducer connectors left LF right LF MF HF
The K1-SB is equipped with one 4-point speakON connector.
K1-SB
IN
KS28 is equipped with one 4-point speakON connector.
KS28
IN
1k = IN k
1 - = IN -
Znom. = 4 Ω
Readmanual and safety
instructionsbefore use
Madein France
EuropeanCommunity
SAFE USE:
16 KS28
FOROTHERCONFIGURATIONS,CHECKMECHANICAL
SAFETYWITHSOUNDVISIONSOFTWARE
USEONLYWITHL-ACOUSTICSAMPLIFIEDCONTROLLERS .
KS28
Weight:79 kg / 174 lb
Internal pinout for L-Acoustics subwoofers
speakON points 1 + 1 - 2 + 2 -
Transducer connectors LF + LF - Not linked Not linked
K2/KS28 user manual (EN) version 3.0 18

Loudspeaker connection
Connection to LA4X
Maximum number of enclosures per LA4X
enclosure max enclosures in parallel *max enclosures per controller
K2 1 1
*For passive loudspeakers, the value corresponds to the number of enclosures in parallel on the output. For active
loudspeakers, the value corresponds to the number of sections in parallel on the output.
Impedance load
K2
1 enclosure: LF 8 Ω / MF 8 Ω / HF 16 Ω
Connecting 3-way active enclosures
custom speakON-to-PA-COM on speakON output
L-Acoustics does not supply the speakON-to-PA-COM interface.
It must be built with two 4-point speakON connectors and a female 8-point PA-COM connector (no cable clamp).
OUT1/OUT2 OUT3/OUT4
speakON to PA-COM
Connection to LA12X
Maximum number of enclosures per LA12X
enclosure max enclosures in parallel *max enclosures per controller
K2 3 3
K1-SB 1 4
KS28 1 4
*For passive loudspeakers, the value corresponds to the number of enclosures in parallel on the output. For active
loudspeakers, the value corresponds to the number of sections in parallel on the output.
Impedance load
K2
1 enclosure: LF 8 Ω / MF 8 Ω / HF 16 Ω
2 enclosures in parallel: LF 4 Ω / MF 4 Ω / HF 8 Ω
3 enclosures in parallel: LF 2.7 Ω / MF 2.7 Ω / HF 5.2 Ω
KS28 K1-SB
1 enclosure: 4 Ω
19 K2/KS28 user manual (EN) version 3.0

Loudspeaker connection
Connecting 3-way active enclosures
DO on CA-COM output
CA-COM
DO DO
Connecting subwoofers
SP and SP-Y1 on speakON output
OUT1/OUT2 OUT3/OUT4
same as OUT1/OUT2
SP SP-Y1
CC4FP
CH(1) (OUT1)
CH(2) (OUT2)
DO and DOSUB-LA8 on CA-COM output
CA-COM
DO
DOSUB-LA8
SPK1 (OUT1)
SPK2 (OUT2)
SPK3 (OUT3)
SPK4 (OUT4)
K2/KS28 user manual (EN) version 3.0 20