Introduction
Providing quality sound reinforcement is essential for businesses in the audio industry, whether for large-scale productions or smaller events. The QSC K Family of products is designed for unparalleled performance in flexible, easy-to-use configurations, making them ideal for a broad range of rental applications. These loudspeakers offer long-term durability and a professional appearance suitable for any situation. The K Family ensures users can meet diverse customer demands.
QSC's K Family products feature unique pole cup mounts. The K.2 Series models include a dual pole cup mount with standard and -7.5° down-tilt options. The KW and KLA Series feature the QSC Tilt-Direct™ pole cup mount, which tilts downward via a dial (-7.5° on KW, -9° on KLA12) to direct acoustic energy towards the audience and away from reflective surfaces. This is particularly beneficial for maximizing coverage from high stand-mounted loudspeakers. The KW153 model includes a standard pole cup.
Images of QSC K.2 Series, KLA Series, and KW Series loudspeakers.
Directivity Matched Transition™ (DMT) for Rental Applications
Directivity Matched Transition (DMT) is a key innovation in professional audio that optimizes loudspeaker performance by matching woofer size to waveguide dispersion. The principle is that smaller woofers beam less and require wider waveguides (90°-105°), while larger woofers beam more and need narrower waveguides (60°-75°). This matching ensures consistent sound dispersion and sensitivity across the frequency range.
Matching both the width and height of the waveguide to the woofer results in smoother off-axis response and optimized power response, avoiding problematic vertical off-axis response. For short-throw applications like front fill or monitors, smaller woofer models with wider coverage are preferred for their compact footprint and wide dispersion, without sacrificing power.
Diagrams illustrating the relationship between woofer size (8", 10", 12") and corresponding waveguide dispersion angles (105°, 90°, 75°).
DMT Quick Guide
The following chart provides a guide to selecting the appropriate K Family loudspeaker and subwoofer based on the DMT concept and application:
| DMT Application | 120° | 105° | 90° | 75° | 60° | SUB |
|---|---|---|---|---|---|---|
| Small venue, corporate function, lounge-bar, distributed front-fill / delay-fill / balcony fill, dj monitor, console monitor | K8.2 | K10.2 | K12.2 | KW122 | KS112 | |
| All purpose PA, mid-size venue, mid-throw, vocal wedge or keyboard wedge, backline acoustic amp | K8.2 | K10.2 | K12.2 | KW122 | KS212C | |
| All purpose PA, mid-size venue, longer-throw, drum or keyboard wedge, backline acoustic amp | K10.2 | K12.2 | KW122 | KS118 | ||
| High SPL, large venue, long-throw, highly array-able and modular building block, centre-cluster, drum-fill or side-fill | 2x KW152 | KW153 | KW152 | |||
| High SPL, large venue, long-throw, horn-loaded midrange for increased vocal clarity, or side-fill on large stage | KW153 | |||||
| Bandpass enclosure design, high output in an ultra-compact form factor, highly transportable, for all entertainment applications | KS112 | |||||
| Dual bandpass enclosure design, cardioid radiation with 15 dB rejection at the rear, highly transportable, ideal for mobile entertainers and mid-sized venues | KS212C | |||||
| Direct radiating subwoofer, impressive LF performance, omnidirectional or cardioid radiation (cardioid requires two or more units); ideal for live reinforcement. | KS118 |
FACT: Every K family full-range loudspeaker, from the smallest model to the largest, features Intrinsic Correction™ EQ employing FIR linear phase filters, which are more commonly found on high-end DSP processors.
Directivity Matched Transition™ (DMT) — Throw this!
The term "throw" in audio refers to the distance a loudspeaker can produce an intelligible signal at a sufficient volume. Sound propagates and attenuates with distance; air absorption also affects higher frequencies. Intelligibility depends on the signal-to-noise ratio. This guide uses the common industry term "throw" to describe loudspeaker performance at distance.
Short-throw loudspeakers have wide dispersion, operate at lower SPLs due to proximity, and use smaller woofer cones. They offer flat frequency response and wide horizontal coverage for audiences in close proximity. Examples include QSC K8.2 and K10.2.
Medium-throw loudspeakers have narrower dispersion, requiring higher maximum SPL, often achieved with larger woofer cones (12-inch or 15-inch) for increased sensitivity. Examples include QSC K12.2 and KW122.
Long-throw loudspeakers feature very narrow dispersion (60° or less) with a narrower horn pattern that increases on-axis sensitivity. This is matched with higher sensitivity woofers for greater acoustic output. They are effective for covering large distances and array well with minimal overlap, serving as modular building blocks for arrays. Examples include QSC KW152, KW153, and KLA12.
Sound Pressure Level (SPL) Table
The table below shows nominal sound pressure levels (C-weighted) at various distances, calculated from the 1m long-term or continuous maximum SPL for each K family loudspeaker or array. Air absorption effects on high frequencies are not factored in.
| Model: | DMT | 1 m (3 ft) | 4 m (13 ft) | 8 m (26 ft) | 16 m (53 ft) | 32 m (105 ft) |
|---|---|---|---|---|---|---|
| K8.2 | 110° | 122 dB | 110 dB | 104 dB | 98 dB | 92 dB |
| K10.2 | 90° | 124 dB | 112 dB | 106 dB | 100 dB | 94 dB |
| K12.2 | 75° | 126 dB | 114 dB | 108 dB | 102 dB | 96 dB |
| K122 | 75° | 125 dB | 113 dB | 107 dB | 101 dB | 95 dB |
| K153 | 75° | 128 dB | 116 dB | 110 dB | 104 dB | 98 dB |
| KW152 x 1 | 127 dB | 115 dB | 109 dB | 103 dB | 97 dB | |
| KW152 x 2 | 60° | 130 dB | 118 dB | 112 dB | 106 dB | 100 dB |
| KW152 x 4 | 133 dB | 121 dB | 115 dB | 109 dB | 103 dB | |
| KLA12 x 1 | 90 x 15° | 125 dB | 113 dB | 107 dB | 101 dB | 95 dB |
| KLA12 x 2 | 90 x 30° | 128 dB | 116 dB | 110 dB | 104 dB | 98 dB |
| KLA12 x 4 | 90 x 60° | 131 dB | 119 dB | 113 dB | 107 dB | 101 dB |
Diagrams showing a vertical array of four KLA12 loudspeakers and a horizontal array of two KW152 loudspeakers.
TIP: When arraying two KW152 60° boxes, avoid hard packing the 18° sidewalls. This results in a 36° splay and severe comb filtering. Instead, use a wider 60° splay between boxes to minimize overlap and broaden the total coverage angle to 120°.
K Family: Subwoofers
The QSC K Family offers four subwoofer options that complement the full-range loudspeakers:
- KS112: A single 12-inch bandpass subwoofer with an ultra-compact enclosure, fitting into tight spaces, such as under riser stages.
- KS212C: A dual 12-inch, dual bandpass subwoofer with cardioid radiation (15 dB rear rejection). It is highly transportable and suitable for mobile entertainers and mid-sized venues, usable in vertical or horizontal deployment.
- KS118: A single 18-inch front-loaded, dual-ported subwoofer providing deep, powerful bass. Its size and weight offer a stable base for pole-mounting loudspeakers, especially the larger KW Series.
- KLA181: A single 18-inch front-loaded subwoofer with four reflex ports and integral rigging hardware for suspension with KLA12 line arrays.
Images of QSC K Family subwoofers: KS212C, KS112, KS118, and KLA181.
Poles and Extension Accessories
QSC provides threaded accessory poles SP-26 (26 in / 66 cm) and SP-36 (36 in / 91 cm, included with KS212C). These are optimized for safe use with 12-inch models or larger. For smaller models (CP8, CP12, K8.2, K10.2), the optional SP-16X (16 in / 41 cm) Pole Extension Accessory is available for increased elevation.
Warning: Use the Pole Extension only with the smaller CP8, CP12, K8.2, and K10.2 models.
Diagrams illustrating pole and extension accessory configurations for various QSC loudspeaker models (e.g., K12.2 or larger, K8.2 and K10.2).
Subwoofer Quantity Determination
Determining the number of subwoofers required involves considering factors similar to choosing main loudspeakers:
- Content: Live sound reinforcement or recorded music?
- Space constraints: Available deployment area?
- Desired bass extension and SPL?
- Budget constraints?
Additional considerations include:
- Subwoofer placement: Flown, ground-stacked, or a combination?
- Content type: Rock, jazz, rap, reggae, etc.?
- Stereo deployment: Left-right or mono block?
- Environment: Indoors or outdoors?
A suitable top-to-subwoofer ratio is crucial, and a "one size fits all" formula is insufficient. A baseline for systems requiring full-range performance down to 40 Hz and below is often a 1:1 top-to-sub ratio indoors. For outdoor applications, where low-frequency energy is not contained by boundaries, this ratio may increase to 1:2.
System diagrams illustrating recommended loudspeaker and subwoofer configurations for a Small Club or Function Room, a Medium Club or Gymnatorium, a Medium Ballroom, and a Theatre/Auditorium with balcony.
Subwoofers: Ground-Stacked vs. Flown
QSC offers ground-stacked (KS112, KS212C, KS118) and flown (KLA181 only) subwoofer options. The KLA181 can also be ground-stacked and has hardware for flying within a KLA12 array.
Ground-Stacked Subwoofers: This is the simpler configuration for setup and deployment. It offers an additional 3 dB of "free" bass due to ground-plane coupling and simplifies wiring. The main drawback is a greater drop-off in SPL from front to rear of the audience.
Flown Subwoofers: While more complex to set up, flown subwoofers provide a more uniform SPL front-to-back across the audience area due to consistent distance. They also tend to integrate better acoustically with the rest of the system. A disadvantage can be the lack of a substantial surface for plane coupling, though ceilings can serve this purpose.
NOTE: In applications like auditoriums or theatres, using both flown and stacked subwoofer configurations is common but requires careful DSP alignment.
Diagrams illustrating ground-stacked and flown subwoofer configurations.
K Family – Rigging and Suspension
The K.2, KW, and KLA Series offer various methods for permanent or temporary rigging (flying).
K.2 Series
Each K.2 Series full-range model (K8.2, K10.2, K12.2) can be suspended using integrated M10-threaded pick points on the top, back, and/or side, allowing for vertical (HF on top) or horizontal orientation. Use only rated forged shoulder eyebolts.
Loudspeakers can also be mounted via yoke brackets to walls or ceilings for permanent installations. Yoke mounts are available as accessories. A yoke can also attach to a lighting claw or truss clamp for temporary suspension.
Images of QSC K.2 Series rigging accessories: Yoke Bracket and Truss Clamp.
TIP: Truss clamps are available from rigging supply companies like ATM Flyware (http://adapttechgroup.com/index.html).
KW Series
The KW122 has seven M10-threaded pick points: two on the top, two on each side, and one on the rear. It can be hung vertically using the top pick points, with coverage angle adjusted via the rear pick point. It can also be hung horizontally using the KW122 Suspension Kit, which includes M10 forged eyebolts and a pull-back bar. Eyebolts can be installed on either side for horn orientation.
The KW152 and KW153 have seven M10-threaded pick points: two on the top, two on the bottom, and three on the rear.
Images of KW152 and KW153 loudspeakers rigged for suspension.
Truss clamps provide a quick, easy, and safe method for hanging KW loudspeakers from a truss or rigging pipe.
KLA Series
The KLA Series line array modules offer a fast and simple rigging system with the unique self-contained SOLO™ (Single-Operator Logistics) system, requiring no special tools. Each element has four M10-threaded points on the top and one in the bottom center rear for aiming.
For portable or touring applications, the KLA AF12 array frame facilitates rigging, allowing mounting to the top of a KLA12 cabinet or KLA181 subwoofer. The frame's pick bar can face forward or aft to adjust vertical focus and center of gravity.
Diagrams showing KLA Series line array configurations, including a 5 x KLA12 array and a 3 x KLA12 array with 2 x KLA181 subwoofers.
Warning: The suspension and mounting of loudspeakers present potential safety hazards. QSC is not liable for the structural integrity of facilities. Users and installers are responsible for proper installation, compliance with standards, and regulatory requirements. Rigging or suspension should only be performed by certified and licensed technicians.
K Family – Power Efficiency
The KW and KLA loudspeaker models utilize a 1000-watt class D power amp module. The K.2 Series models feature an updated 2000-watt class D module with user-selectable DSP presets, user-definable DSP settings, and recallable scenes.
These power amp designs are highly efficient. For example, a single KW or KLA Series loudspeaker operating at 1/8 power draws only 2.1 amps at 120 VAC. This allows up to five K Family loudspeakers (including subwoofers) to run off a single 15-amp AC circuit, or up to eight off a 20-amp circuit. A full sound system, such as four KW153 tops plus four KS118 subs per side, can be powered from a single 20-amp outlet without requiring specialized AC power distribution.
Images of the power amp modules for QSC KW Series, KLA Series, and K.2 Series loudspeakers.
Power Consumption Tables:
KW and KLA Series
| Voltage | One loudspeaker | Two loudspeakers | Four loudspeakers | Six loudspeakers |
|---|---|---|---|---|
| 100 VAC | 2.3 A* | 4.6 A* | 9.2 A * | 13.8 A* |
| 120 VAC | 2.01 A* | 4.02 A* | 8.04 A* | 12.06 A* |
| 230 VAC | 1.13 A* | 2.26 A* | 4.52 A* | 6.78 A* |
* Average output 1/8 of full power
K.2 Series
| Voltage | One loudspeaker | Two loudspeakers | Four loudspeakers | Six loudspeakers |
|---|---|---|---|---|
| 100 VAC | 2.1 A* | 4.2 A* | 8.4 A * | 12.6 A* |
| 120 VAC | 1.9 A* | 3.8 A* | 7.6 A* | 11.4 A* |
| 230 VAC | 1.1 A* | 2.2 A* | 4.4 A* | 6.6 A* |
* Average output 1/8 of full power
Green Power
K power modules are efficient both in use and when idle. When no signal is detected for over five minutes, the DSP enters standby mode, shutting down the amplifier. This conserves energy and reduces the need for remote AC relays. Upon signal restoration, the DSP immediately reactivates the amplifier with no noticeable delay.
Wiring
The K.2 and KW series loudspeakers include a 10-foot (3 meter) detachable locking IEC power cable. KLA series cabinets feature Neutrik powerCON AC connectors for input and output. KLA12 cabinets come with a 12-foot (3.6 meter) main power cable and a 2-foot (0.6 meter) AC jumper. KLA181 subwoofers include a 12-foot (3.6 meter) main power cable and a 3-foot (1 meter) AC jumper. For audio daisy-chaining, KLA12 includes a 2-foot XLR to XLR jumper, and KLA181 includes a 3-foot XLR to XLR jumper.
Combination cables with custom lengths are available from third-party suppliers, integrating AC power (IEC or powerCON) with an XLR audio channel. Hum is prevented by the tightly twisted conductor pair in the audio cable and the high-performance CMR balanced circuit.
Diagram illustrating wiring connections, including IEC power cables, Neutrik powerCON connectors, and XLR jumpers.
K Family - Transportation
QSC offers optional accessories for protecting and transporting the K Family products.
Totes and Covers
K.2 Series: Optional soft, padded totes made from weather-resistant, heavy-duty Nylon/Cordura® material are available for K8.2, K10.2, and K12.2 models. Side-flap access to the aluminum top handle allows for convenient vertical transport.
Subwoofers: Covers are available for the KS112, KS212C, KS118, and KLA181 subwoofers.
Outdoor Covers: Optional nylon fabric and mesh covers are available for temporary outdoor use of K8.2, K10.2, or K12.2 in adverse weather. These feature a removable amplifier panel for access and a vented panel for airflow. These covers are not intended for permanent outdoor installation or severe weather conditions.
KW Series: Optional soft, padded covers (no straps) made from weather-resistant, heavy-duty Nylon/Cordura® material are available for KW122, KW152, and KW153 models. They also feature side-flap access to the aluminum top handle for convenient vertical transport.
Images of optional totes and covers for QSC K.2, KW, and subwoofer series.
Application Suggestions
Corporate AV: Function Room
Scenario: Typical hotel or conference center function room (approx. 30 x 50 ft, 1500 ft²), seating 50-100 people. Often used for corporate presentations, seminars, or training events, and can also host small ceremonies or events requiring music reinforcement.
Option 1: Basic Speech and Music Playback
Recommended system: QSC K8.2 loudspeakers with 105° DMT coverage.
Diagram showing a basic system with a mixer connected to two QSC K8.2 loudspeakers on stands.
Option 2: Enhanced Music Playback
Recommended system: Add a QSC KS112 subwoofer for greater impact on music playback.
Diagram showing a system with a mixer connected to two QSC K8.2 loudspeakers, with a QSC KS112 subwoofer below one of them.
TIP: Rotate the KS112 for an even lower footprint or to fit under a riser.
Live Sound Reinforcement: Live Bar
Scenario: Live music bar or club (approx. 40 x 60 ft, 2400 ft²), seating 100-200 people. Stage is typically against a back wall or corner. Music levels increase throughout the evening.
Option 1: Light Acoustic Instrument Reinforcement
Recommended system: QSC K10.2 loudspeakers with short-throw 90° DMT coverage.
Diagram showing a system with a mixer connected to two QSC K10.2 loudspeakers on stands.
TIP: For backline applications, the K10.2 is excellent for acoustic guitar and keyboards. Its MIX OUT also serves as a DI output for the FOH mixer.
Option 2: High-Impact Music Reinforcement
Recommended system: QSC KW122 loudspeakers for more punch.
Diagram showing a system with a mixer connected to two QSC KW122 loudspeakers, with two QSC KS118 subwoofers below them. Foldback sends are also shown.
TIP: For wider coverage, add more splayed KW122s. Add more KS118 subwoofers to increase bass energy.
Live Sound Reinforcement: Hall
Scenario: Multi-purpose venue like a school assembly hall, community hall, or church hall (approx. 50 x 70 ft, 3500 ft²), seating 200-400 people. Features a hard flat floor and stackable or retractable seating. The stage is at one end, requiring longer throw and narrower coverage.
Option 1: Basic Speech and Playback Music
Recommended system: QSC K12.2 loudspeakers with 75° DMT coverage.
Diagram showing a system with a mixer connected to two QSC K12.2 loudspeakers on stands.
NOTE: For quick PA deployment, connect the announcer's microphone directly into one K Family loudspeaker and loop the signal to others.
Option 2: High-Impact Live Music
Recommended system: QSC KW153 loudspeakers for higher SPL with 75° DMT coverage.
Diagram showing a system with a mixer connected to two QSC KW153 loudspeakers, with two QSC KS118 subwoofers below them. Foldback sends are also shown.
Corporate AV: Ballroom
Scenario: Hotel or conference center ballroom (approx. 50 x 70 ft, 3500 ft²), seating 200-400 people. Often has moveable airwalls or concertina doors. Used for presentations, seminars, training, or events requiring a DJ or band. A temporary stage is typically across a long wall, needing wider coverage.
Option 1: Ground-Stacked Speech and Playback Music
Recommended system: Ground-stacked QSC KW152 loudspeakers with QSC KS118 subwoofers.
Diagram showing a system with a mixer connected to four QSC KW152 loudspeakers on stands, with two QSC KS118 subwoofers below them. Includes bus/matrix and delay connections.
TIP: When arraying two KW152 boxes, apply a high shelf filter (3 dB boost at 1.5 kHz, 12 dB/oct slope) to compensate for LF/MF summing, similar to KLA's Ar-Q compensation.
Option 2: Flown High-Impact Live Music
Recommended system: Flown QSC KLA12 loudspeakers with QSC KS118 subwoofers, potentially using airwall track adaptors.
Diagram showing a flown system with multiple QSC KLA12 loudspeakers and QSC KS118 subwoofers, suspended from an airwall track. Includes bus/matrix and delay connections.
TIP: Airwall track adaptors like Alumalok and Titan are useful for suspending distributed systems in ballrooms (www.alumalok.com, www.airwallhangers.com).
Live Sound Reinforcement: Theatre
Scenario: Modern community theatre or traditional proscenium arch theatre (approx. 80 x 100 ft, 8000 ft²), seating 400-800 people. Features stadium or raked seating. An ideal deployment uses a flown line array for full vertical coverage. In older buildings without rigging points, ground stacking is used.
Option 1: Ground-Stacked Speech and Playback Music
Recommended system: Ground-stacked QSC KW153 loudspeakers with QSC KS118 subwoofers, and QSC KLA12 loudspeakers for stage lip/front fill.
Diagram showing a ground-stacked system with QSC KW153 loudspeakers, QSC KS118 subwoofers, and QSC KLA12 loudspeakers for front fill. Includes mixer, matrix, and output connections.
TIP: Set the lower KLA's Tilt-Direct dial to 0° to steer sound up towards a balcony.
Option 2: Flown High-Impact Live Music
Diagram showing a flown system with multiple QSC KLA12 loudspeakers and QSC KS118 subwoofers, potentially with QSC KLA181 subwoofers.
TIP: Use EASE Focus to predict vertical coverage of KLA arrays. Download EASE Focus for free from: https://www.qsc.com/resources/software-and-firmware/loudspeakers/
Live Sound Reinforcement: Outdoor Stage
Scenario: Small outdoor stage (approx. 100 ft, 12,000 ft²), for 800+ people. Can be a band shell or temporary stage, used for community events, fairs, or festivals.
Option 1: Ground-Stacked Speech and Playback Music
Recommended system: Ground-stacked QSC KW152 loudspeakers with QSC KS118 subwoofers, and QSC KLA12 loudspeakers for stage lip/front fill and out-fill.
Diagram showing a ground-stacked system with QSC KW152 loudspeakers, QSC KS118 subwoofers, and QSC KLA12 loudspeakers for front fill and out-fill. Includes FOH mixer, sub aux, and matrix connections.
TIP: The KLA also serves as an excellent stage lip front-fill loudspeaker for wider stage applications.
Option 2: Flown High-Impact Live Music
Recommended system: Flown QSC KLA12 loudspeakers with QSC KS118 subwoofers, and QSC KW153 loudspeakers for out-fill.
Diagram showing a flown system with QSC KLA12 loudspeakers, QSC KS118 subwoofers, and QSC KW153 loudspeakers for out-fill. Includes FOH mixer, sub aux, and matrix connections.
TIP: When adding out-fill loudspeakers, invert L/R to R/L to maintain stereo imaging across a wider area.
Monitor Rigs and Backline
Small Monitor Rig:
Diagram showing a small monitor rig setup with QSC K10.2 and QSC K12.2 loudspeakers connected to foldback sends from a mixer.
TIP: You can power up to five K Family products (any models) from a single 15 A circuit (120 V) or 7.5 A circuit (230 V).
Large Monitor Rig:
Diagram showing a large monitor rig setup with multiple QSC K10.2 and QSC K12.2 loudspeakers connected to monitor buses and foldback sends from a mixer.
Contacts
QSC provides contact information for various regions:
- QSC, LLC
1675 MacArthur Boulevard
Costa Mesa, CA 92626-1468
USA
Website: www.qsc.com/contact-us/
Tel: (800) 854-4079
Tel: +1 (714) 754-6175
Fax: +1 (714) 754-6174
E-mail: info@qsc.com - Application Engineering and Technical Services
Tel: (800) 772-2834
Tel: +1 (714) 957-7150
Fax: +1 (714) 754-6173
E-mail: tech_support@qsc.com - QSC UK & Ireland Ltd.
Sales, Market Development & Training Centre
6 Horizon Business Village
1 Brooklands Road
Weybridge, KT13 0TJ
United Kingdom
Tel.: +44 1932 639 600
Website: https://www.qsc.com/uk - QSC EMEA GmbH
Regional Headquarters
Am Ilvesbach 6
74889 Sinsheim
Germany
Tel.: +49 7261 6595 300
Fax: +49 7261 6595 333 - QSC Netherlands BV
Business Development, Training & Service Repairs
Gerdina's Hof 61
4191 MX Geldermalsen
The Netherlands
Tel.: +49 7261 65 95 550
Email: emea.service@qsc.com - QSC Asia, Ltd.
Cable TV Tower, Suites 1301 & 2807A
9 Hoi Shing Road, Tsuen Wan
Hong Kong - QSC SAARC
Sales and Market Development
A-502, 5th Floor | Signature Tower |
Brigade Golden Triangle | Kattamnallur Junction | Old Madras Road |
Bengaluru – 560 049 | Karnataka, India
Tel.: +91 80 6178 0600
Website: https://www.qsc.com/in
©Copyright 2020 QSC, LLC. All rights reserved.
qsc.com • 1-800-854-4079 Rev. B 05/2020
