L-Acoustics KS21 Owner's Manual
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L-Acoustics KS21 Owner's Manual

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Summary of Contents for L-Acoustics KS21

  • Page 1 KS21 owner's manual (EN)
  • Page 2 Document reference: KS21 owner's manual (EN) version 2.1 Distribution date: September 30, 2019 © 2019 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.

  • Page 3: Table Of Contents

    Contents Safety................................5 Instructions..............................5 Introduction................................ 7 KS21 compact reference subwoofer......................7 How to use this manual..........................7 System components.............................8 Loudspeaker cables........................... 9 Rigging elements.............................10 Electro-acoustical description..........................11 Preset description............................ 11 Connectors............................. 11 Rigging system description..........................12 KS21..............................12 Rigging elements for own arrays......................14 A15-BUMP............................14...
  • Page 4 Rigging procedures............................47 Flying..............................47 Flying a vertical array with A15-BUMP/A15-RIGBAR................47 Stacking..............................52 Stacking KS21 on KS21-CHARIOT....................52 Attaching K2-JACK stabilizers to KS21-CHARIOT................54 Connection to LA amplied controllers........................ 57 Corrective maintenance............................. 58 Specications..............................63 APPENDIX A: Recommendation for speaker cables....................71...

  • Page 5: Safety

    Respect the Working Load Limit (WLL) of third party equipment. L-Acoustics is not responsible for any rigging equipment and accessories provided by third party manufacturers. Verify that the Working Load Limit (WLL) of the suspension points, chain hoists and all additional hardware rigging accessories is respected.
  • Page 6 This system is intended for use by trained personnel for professional applications. 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 documents without prior notice.

  • Page 7: Introduction

    21" transducer mounted in a bass-reex tuned enclosure. KS21 operates from 29 Hz to 60 Hz when associated with A15, or 30 Hz to 100 Hz when associated with A10. KS21 features L-Vents that substantially reduce turbulence and port noise at high levels while also increasing LF efciency.

  • Page 8: System Components

    Refer to the LA4X / LA8 / LA12X user manual for detailed instructions about the whole cabling scheme, including modulation cables and network. Rigging elements A15-BUMP Flying frame for vertical deployment of A15 and KS21 A15-RIGBAR Rigging bar and pullback for A15 and KS21 KS21-OUTRIG...

  • Page 9: Loudspeaker Cables

    0.7 m / 5 m / 10 m / 25 m CH(1) CH(2) SP.7 / SP5 / SP10 / SP25 SP-Y1 SPK1 SPK2 0.7 m / 10 m / 25 m SPK3 SPK4 DO.7 / DO10 / DO25 DOSUB-LA8 KS21 owner's manual (EN) version 2.1...

  • Page 10: Rigging Elements

    System components Rigging elements A15-BUMP A15-RIGBAR KS21-OUTRIG KS21-CHARIOT K2-JACK CLAMP250 KS21- KS21-PLA KS21-COV CHARIOTCOV KS21 owner's manual (EN) version 2.1...

  • Page 11: Electro-Acoustical Description

    IN A 0 dB 0 ms OUT 2 OUT 3 OUT 4 Connectors KS21 2 × 4-point speakON Internal pinout for L-Acoustics subwoofers speakON points Transducer connectors LF + LF - Not linked Not linked KS21 owner's manual (EN) version 2.1...

  • Page 12: Rigging System Description

    Push and slide to unlock the spring-loaded pin. The rigging elements are tted with yellow safety labels that are visible when they are not safely locked. KS21 displays two ground runners on the bottom and two matching tracks on the top. KS21 owner's manual (EN) version 2.1...
  • Page 13 Eight corner stops protect the side panels during handling. The logo on the enclosure front can be rotated to adapt to every conguration. KS21 features a 35 mm pole-socket which contains an M20×150 insert. Use a 35 mm diameter pole The pole can be non-threaded or with M20 thread.

  • Page 14: Rigging Elements For Own Arrays

    Rigging elements for own arrays A15-BUMP A15-BUMP is a reversible rigging frame for ying vertical arrays of KS21. A15-BUMP is equipped with rotating rigging arms and ball-locking pins, to match the rigging systems of KS21 on either side. KS21 owner's manual (EN) version 2.1...
  • Page 15 9 10 11 12 13 14 15 16 FRONT 9 10 11 12 13 14 15 16 A15-BUMP can be used as the main lifting accessory for ying vertical arrays of KS21 with one or two lifting points. KS21 owner's manual (EN) version 2.1...

  • Page 16: A15-Rigbar

    A15-RIGBAR A15-RIGBAR is a reversible rigging bar. It can be used as a pullback or for ying vertical arrays of up to four KS21. A15-RIGBAR is equipped with rotating rigging arms and ball-locking pins, to match the rigging systems of KS21 on either side.
  • Page 17 Rigging system description A15-RIGBAR can be used as the main lifting accessory, to provide a lightweight solution for ying four KS21 with one or two lifting points. The pickup points are compatible with Ø12 mm shackles WLL 1 t (two provided) and CLAMP250.

  • Page 18: Rigging Elements For Stacked Arrays

    KS21-OUTRIG KS21-OUTRIG is a set of two stability bars for KS21. Secure KS21-OUTRIG at the bottom of a KS21 array to improve the stability of the array. The use of KS21-OUTRIG is mandatory when A15 Wide/Focus or A10 Wide/Focus are stacked on top of KS21.

  • Page 19: K2-Jack

    Rigging system description Two runners on each KS21-OUTRIG bar ensure stability. Four Ø 6.5 mm holes are available to secure the assembly to the oor. ⌀6.5 mm hole (x4) K2-JACK K2-JACK is a set of two bars and four feet with screw jacks and hand wheels. K2-JACK can be tted onto...
  • Page 20 Rigging system description KS21 owner's manual (EN) version 2.1...

  • Page 21: Storage And Handling Elements

    Rigging system description Storage and handling elements KS21-CHARIOT KS21-CHARIOT is a chariot designed to transport a stack of up to three KS21. It features two rigging arms to secure the lower KS21. KS21-CHARIOT is intended for use only with L-Acoustics KS21.

  • Page 22: Ks21-Pla

    Multiple KS21-CHARIOT can be stacked for storage. KS21-PLA KS21-PLA is a dolly board that can be secured to the front of a KS21 with two spring-loaded pins. KS21-PLA is intended for use only with L-Acoustics KS21. Use with other equipment may result in instability causing injury.

  • Page 23: Ks21-Cov And Ks21-Chariotcov

    KS21-COV is an individual cover for KS21 on KS21-PLA. Two aps provide access to the connector plate. KS21-CHARIOTCOV is a cover for a stack of two to three KS21 on KS21-CHARIOT. To t a stack of two KS21, KS21-CHARIOTCOV must be folded inwards and secured with the integrated velcro straps. the logo must be...

  • Page 24: Mechanical Safety

    Mechanical safety Mechanical safety Flown congurations The KS21 rigging system complies with 2006/42/EC: Machinery Directive. It has been designed following the guidelines of BGV-C1. 2006/42/EC: Machinery Directive species a safety factor of 4 against the rupture. The own deployments described in this manual achieve a safety factor of 4 or more.
  • Page 25 Soundvision calculations are based on usual environmental conditions. A higher safety factor is recommended with factors such as extreme high or low temperatures, strong wind, prolonged exposition to salt water, etc. Always consult a rigging specialist to adopt safety practices adapted to such a situation. KS21 owner's manual (EN) version 2.1...

  • Page 26: Loudspeaker ConGurations

    Loudspeaker congurations KS21 in standard conguration Deployed in a standard conguration, a KS21 system operates with an omnidirectional directivity pattern over the nominal bandwidth of the KS21 enclosure. The [KS21_60] and [KS21_100] factory presets provide the subwoofer system with an upper frequency limit at 60 Hz and 100 Hz respectively in order to optimize the acoustic coupling with a main full-range system.

  • Page 27: Ks21 In Cardioid ConGuration

    KS21 in cardioid conguration Deployed in a cardioid conguration, a KS21 system produces a rear SPL rejection. The deployment consists of an array of four KS21 with one element turned towards the rear (reversed). Refer to the Cardioid Conguration technical bulletin for more information.

  • Page 28: Inspection And Preventive Maintenance

    Acoustics Perform the Enclosure check (p.44). Perform the Listening test (p.46) to detect any degradation in sound quality. If necessary, refer to the Corrective maintenance (p.58) section for speaker repair kits and maintenance instructions. KS21 owner's manual (EN) version 2.1...

  • Page 29: Rigging Part Inspection

    5. Check the moving parts. Make sure that the mechanism engages correctly. What to do next If a problem is detected, perform the authorized maintenance operations or contact your L-Acoustics representative. Mechanical system overview Critical parts of the lifting chains are highlighted.
  • Page 30 Inspection and preventive maintenance A15 Wide/Focus and KS21 array with A15-BUMP and M-BAR Shackles (p.35) Ball-locking pins (p.36) the yellow label is present Ball-locking pins (p.36) the rigging arm can rotate freely Rigging check (p.42) Runners and corner stops (p.38) Rigging check (p.42)
  • Page 31 Inspection and preventive maintenance KS21 array with A15-RIGBAR Shackles (p.35) Ball-locking pins (p.36) Rigging check (p.42) Runners and corner stops (p.38) KS21 owner's manual (EN) version 2.1...
  • Page 32 Inspection and preventive maintenance A15 Wide/Focus and A-MOUNT pole-mounted on KS21 the bottom inserts are not damaged all screws are tightened the angle axis is not bent Threaded knobs (p.41) make sure that either the locking cotter pin or the knob is present Make sure the pole is compatible with the KS21 pole socket.
  • Page 33 Inspection and preventive maintenance A15 Wide/Focus stacked on A-TILT and KS21 with KS21-OUTRIG Rigging check (p.42) the bottom inserts are not damaged Runners and corner stops (p.38) all screws are tightened Threaded knobs (p.41) Ball-locking pins (p.36) Runners and corner stops (p.38)
  • Page 34 Inspection and preventive maintenance A15 Wide/Focus stacked on KS21 with K2-CHARIOT and K2-JACK Runners and corner stops Rigging check (p.42) (p.38) Rigging check (p.42) Pole-mount socket (p.40) Runners and corner stops (p.38) the rigging arm can rotate apply the brakes: the stack is...

  • Page 35: Inspection References

    Drive the shackle axis in its lodging. Make sure that the end is ush with the shackle. Repair kits 12 mm shackles A15-BUMP KR CAMAN12L (KR bow shackles 12 mm (x2) ) A15-RIGBAR KR CAMAN12L (KR bow shackles 12 mm (x2) ) Related tasks Rigging part inspection (p.29) KS21 owner's manual (EN) version 2.1...
  • Page 36 Inspection and preventive maintenance Ball-locking pins • Tethers are intact and safely secured. • Test the ball-locking mechanism (see Moving parts (p.37)). Reference pictures A15-BUMP A15-RIGBAR A-TILT M-BAR KS21 owner's manual (EN) version 2.1...
  • Page 37 The pin must remain inside the hole. If the pin is inserted in two plates, the ball must pass through both plates and lock the pin in place. If the check fails, immediately withdraw the product from use and contact L-Acoustics. Repair kits (KR)
  • Page 38 Runners and corner stops • Runners are not worn out. • Screws are tightened. Reference pictures KS21 ground runner KS21 corner stop A15 Wide/Focus ground runner A15 Wide/Focus corner stop A-TILT runner KS21-OUTRIG runner KS21 owner's manual (EN) version 2.1...
  • Page 39 G03468 (KR runners A-TILT ) KS21-OUTRIG G03478 (KR runners KS21-OUTRIG ) Corner stops A15 Wide/Focus / KS21 G03439 (KR corner stops KS21 / A15 ) Screws A15 Wide/Focus G03431 (KR screws and fasteners A15 ) KS21 G03413 (KR screws and fasteners KS21 )
  • Page 40 Repair kits Contact your L-Acoustics representative for repair instructions. Pole-mount socket KS21 G03415 (KR pole mount with insert ) Screws KS21 G03413 (KR screws and fasteners KS21 ) Related tasks Rigging part inspection (p.29) KS21 owner's manual (EN) version 2.1...
  • Page 41 A-MOUNT enclosure knob Repair kits A-MOUNT G03471 (KR threaded knob A-TILT ) A-TILT G03474 (KR threaded knob for pole socket A-TILT ) G03471 (KR threaded knob A-TILT ) Related tasks Rigging part inspection (p.29) KS21 owner's manual (EN) version 2.1...

  • Page 42: Rigging Check

    Inspection and preventive maintenance Rigging check About this task The procedure is described with two KS21 but can be executed identically with two A15 Wide/Focus. Procedure 1. Secure one KS21 on top of another one. Push and slide to unlock the spring-loaded pin.
  • Page 43 Inspection and preventive maintenance 2. Hold the top enclosure by the handles and shake the assembly. The two enclosures remain attached. 3. Unlock the rigging system on both sides. 4. Switch the enclosures and repeat the procedure. KS21 owner's manual (EN) version 2.1...

  • Page 44: Acoustical Check

    6. Press the OK key or the encoder wheel to launch the ENCLOSURE CHECK. The amplied controller generates short sinusoidal signals simultaneously for each connected output. The amplied controller displays the results for each output. KS21 owner's manual (EN) version 2.1...
  • Page 45 • a percentage of variation from the expected range (found in NOK and UNDEF results) • the number of operational transducers out of the total Low variations from the expected range are acceptable: displayed percentage can be different from 0 and all transducers considered operational. KS21 owner's manual (EN) version 2.1...
  • Page 46 2. Carefully clean the speaker with a dry cloth. 3. Perform the reassembly procedure. Replace the speaker gasket and the screws. Apply the recommended torque. 4. Repeat the listening test. If the problem persists, replace the speaker. KS21 owner's manual (EN) version 2.1...

  • Page 47: Rigging Procedures

    Verify that no unattached items remain on the product or assembly. Secondary safety Use available holes on the rigging accessories to implement a secondary safety. Assembly Procedure 1. Prepare a stack of KS21. Connect each enclosure on both sides before adding the new one. KS21 owner's manual (EN) version 2.1...
  • Page 48 Rigging procedures 2. Secure A15-BUMP or A15-RIGBAR on top of the array. A15-BUMP A15-RIGBAR Connect A15-BUMP to the top KS21 on both sides. Connect A15-RIGBAR to the top KS21 on both sides. CLICK! CLICK! Final check Visually check that no yellow labels are visible.
  • Page 49 Rigging procedures 4. Add additional enclosures under the array. a) Lower the array onto a KS21 or a stack of KS21 on KS21-CHARIOT. Align the runners and the tracks. b) Connect the enclosures on both sides. c) Unlock the KS21-CHARIOT rigging arms.
  • Page 50 1. Position a KS21-CHARIOT under the array. Prepare KS21-CHARIOT Make sure the KS21-CHARIOT brakes are not engaged. Make sure the KS21-CHARIOT rigging arms are in the open position. Proceed slowly when lowering the array. 2. Lower the array until it rests on KS21-CHARIOT.
  • Page 51 Rigging procedures 3. Secure the bottom enclosure to KS21-CHARIOT. SHLAK! 4. Disconnect a stack from the array on both sides. Make sure both linking points are disconnected before lifting the array. 5. Lift the assembly and put the stack aside.

  • Page 52: Stacking

    Risk of falling objects Verify that no unattached items remain on the product or assembly. Assembly Procedure 1. Engage both brakes on KS21-CHARIOT. 2. Place KS21 on KS21-CHARIOT and connect the two elements on both sides. KS21 owner's manual (EN) version 2.1...
  • Page 53 Rigging procedures 3. Secure another KS21 on the assembly. Align the runners with the tracks. 4. Repeat until the stack is complete. Final check Visually check that no yellow labels are visible. Manually check that all linking points are secured.

  • Page 54: Attaching K2-Jack Stabilizers To Ks21-Chariot

    Min number of operators Assembly Procedure 1. Attach the K2-JACK bars to KS21-CHARIOT on each side. a) Open the locking handles to insert the studs. b) Raise and turn the locking handles to secure the bars. KS21 owner's manual (EN) version 2.1...
  • Page 55 Insert the feet at both ends of the bar. Pivot the central part so that it comes in contact with the bar. Lock the feet in position by giving a quarter-turn to the locking system. KS21 owner's manual (EN) version 2.1...
  • Page 56 Rigging procedures 4. Rotate the wheels clockwise to raise the array. Stop raising the stack as soon as the wheels get off the ground. KS21 owner's manual (EN) version 2.1...

  • Page 57: Connection To La AmpliEd Controllers

    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. LA8 can drive up to two KS21 per output, but no more than six per controller at high level. KS21 owner's manual (EN) version 2.1...

  • Page 58: Corrective Maintenance

    Corrective maintenance Corrective maintenance KS21 exploded view In order to operate, follow the order outlined here. Each assembly refers to the corresponding D/R procedure and the necessary repair kit. GRILL FIXING BARS LF SPEAKER G03409 KS21 owner's manual (EN) version 2.1...
  • Page 59 KR loudspeaker 21 KS21 ×2 S221 M6×35 Torx Exploded view For safety reasons, always use the new screws and spare parts provided in the KR. If no new screws are available, use blue threadlocker. 3 N.m KS21 owner's manual (EN) version 2.1...
  • Page 60 For safety reasons, always use the new screws and spare parts provided in the KR. If no new screws are available, use blue threadlocker. Slide the xing bars under the vent panel to attach them to the studs, then secure them with the screws. 5 N.m KS21 owner's manual (EN) version 2.1...
  • Page 61 For safety reasons, always use the new screws and spare parts provided in the KR. If no new screws are available, use blue threadlocker. Tilt the speaker to remove it from the cabinet. Carefully disconnect the cables. 5 N.m KS21 owner's manual (EN) version 2.1...
  • Page 62 Corrective maintenance If the speaker gasket is damaged, remove and replace it. KS21 owner's manual (EN) version 2.1...

  • Page 63: SpeciCations

    Rigging components high grade steel with anti-corrosion coating Finish dark grey brown Pantone 426 C Peak level at 1 m under half space conditions using pink noise with crest factor 4 (preset specied in brackets). KS21 owner's manual (EN) version 2.1...
  • Page 64 Specications KS21 dimensions 764 mm / 30 in 602 mm / 23.7 in 752 mm / 29.6 in KS21 owner's manual (EN) version 2.1...
  • Page 65 Specications A15-BUMP specications Description Flying frame for vertical deployment of A15 and KS21 2 × Ø12 mm shackles WLL 1 t Weight (net) 19 kg / 42 lb Material high grade steel with anti-corrosion coating A15-BUMP dimensions 656 mm / 25.8 in 600 mm / 23.6 in...
  • Page 66 Specications A15-RIGBAR specications Description Rigging bar and pullback for A15 and KS21 2 × Ø12 mm shackles WLL 1 t Weight (net) 4.6 kg / 10 lb Material high grade steel with anti-corrosion coating A15-RIGBAR dimensions 750 mm / 29.5 in 89 mm / 3.5 in...
  • Page 67 Specications KS21-CHARIOT specications Description Chariot for up to 3 KS21 Weight (net) 23.6 kg / 52 lb KS21-CHARIOT dimensions 67.8 mm / 2.6 in 840 mm / 33 in KS21 owner's manual (EN) version 2.1...
  • Page 68 4 tilt adjustment screw jacks + bar for K2-CHARIOT Weight (net) 10.1 kg / 22.3 lb (for one stabilizer) Material high grade steel with anti-corrosion coating K2-JACK dimensions 1278 mm / 50.3 in 124 mm / 4.9 in KS21 owner's manual (EN) version 2.1...
  • Page 69 CLAMP250 specications Description Clamp certied for 250 kg Weight (net) 1.8 kg / 4 lb Material high grade steel with anti-corrosion coating CLAMP250 dimensions 167 mm / 6.6 in 103 mm / 4.1 in KS21 owner's manual (EN) version 2.1...
  • Page 70 Specications KS21-PLA specications Description Removable front dolly for 1 KS21 Weight (net) 9.5 kg / 21 lb KS21-PLA dimensions 20 mm / 0.8 in 738 mm / 29 in KS21 owner's manual (EN) version 2.1...

  • Page 71: Appendix A: Recommendation For Speaker Cables

    8 Ω load 4 Ω load 2.7 Ω load Use the more detailed L-Acoustics calculation tool to evaluate cable length and gauge based on the type and number of enclosures connected. The calculation tool is available on our website: https://www.l-acoustics.com/en/installation/tools/...
  • Page 72 L-Acoustics 13 rue Levacher Cintrat - 91460 Marcoussis - France +33 1 69 63 69 63 - info@l-acoustics.com www.l-acoustics.com...

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