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Review: QSC Audio KLA Series Loudspeakers

PAR Contributors divide an ebony and ivory collection of KLA Series loudspeakers to test them from concert roofs, in open fields, and at church. 

KLA Series Features 

The full-range KLA12 is the high-strength, riggable ABS cabinet, residence for two transducers: a 12-inch cone speaker and a 1.75-inch diaphragm compression driver. Its SOLO Rigging System simplifies deployment, as it requires no tools or external hardware to “fly.” 

The KLA12 compression driver is mounted to a 90×18-degree wave guide horn. The cabinet also contains two power amplifiers, each providing 500W RMS continuously for a combined output of 1,000W RMS. Input is balanced XLR female; an additional male XLR is available for signal pass-through. The amplifier accepts line level signal and contains Digital Signal Processor (DSP). Its DSP provides crossover and frequency control (via dial-adjustable Ar-Q Frequency Optimization); limiting/protection; time alignment of the internal transducers; temperature/fan management; and factory voicing/EQ. QSC’s DEEP DSP algorithm provides extended bass response “by actively managing potentially damaging low-frequency transients.” KLA12 features Neutrik powerCON input and loop thru connectors; weight is 55 lbs.; and dimensions are 15- x 23.4- x 16.6-inches. 

The KLA181 subwoofer, while cosmetically similar, is constructed of painted birch plywood, and hosts an 18-inch vented subwoofer transducer capable of 135dB SPL peak output and frequency response down to 33Hz (-10 dB). Power is provided by its integrated power amplifier (1,000W RMS), and QSC’s DEEP DSP is also on board. The sub’s incorporated threaded pole mount allows support of two KLA12 full-range enclosures, and suspension is possible via M10 fittings or KLA12AF Array Frame (the latter was utilized in these evaluations). KLA181 also features Neutrik powerCON connectors; weight is 100 lbs.; and dimensions are 21.6- x 23.1- x 25.7-inches. 

QSC KLA Series in Black: 

Full Concert Sound & Special Outdoor Events

By Will James

I’ve previously reported to you, dear readers, about QSC’s innovative K Series of loudspeakers — so named because each one provides about a Kilowatt of amplified power. I was quite impressed with the audio quality of the K Series and recommended them highly in my full review for PAR

Again, QSC has outdone themselves, this time by introducing a line source version of the K Series, aptly called the KLA Series.

Let me be perfectly clear about the term, “Line Array.” It is an array, or compliment of speakers, that when arrayed in a perfectly straight line, function as one speaker and offer a reasonably coherent wave front. The line array system is generally considered to be “the perfect device” to offer even coverage up to a given width; yet more importantly, it is controllable in its propagation of sound in the vertical plane, through adjustment of the angle between component boxes in the overall system. In other words, you can minimize the spillage of audio into unwanted spaces, and focus the energy of the system into the places you actually want sound. However, the bend of a typical line array will vary frequency response from point to point within the actual wave composite.


The KLA Series incorporates a very interesting control into its DSP called Arcuate Equalization. Put simply, this circuit allows you to decide how many top boxes to be in the array; then you can select that number on a rotary control on the power amp. The DSP will automatically (electronically) adjust the waveform pattern, such that an obvious arc in the array will properly couple the EQ and function of the boxes, ensuring it acts like a traditional Line Array with a cohesive waveform. The boxes only interlock with each other at a fixed angle, and this selector will ensure the proper fit of each component to the waveform, maintaining proper EQ and uniformity of dispersal of sound.

In Use

QSC supplied us with four KLA 181 subwoofers, four KLA12 full-range speakers, and two KLA12AF Array Frame kits with associated hardware. It was a perfect setup for flying two subs and two tops per side via Genie Towers with my live sound firm, Atlantis Audio. 

Fortunately, this QSC rig showed up the very day that we were headed off to do a car show that has 1,000 classic entries spread over four baseball fields, plus a main stage for concerts. We decided to employ the KLA Series as music fills for the viewing fields, with iPod stereo signal fed via matrix master from our Midas Legend (An analog live mix console. What can I say? I’m 58). 

Two separate KLA arrays covered all four fields with great evenness. The combination of two subs on top and two full-range cabs under the subs was a perfect compliment for the job at hand. We supplied one 20 Amp/125 Volt circuit to each array, as the cabinets linked conveniently with Neutrik powerCON connectors, color coded for proper feed direction. All told, we had both arrays out of their shipping boxes and up, in action, in less than 20 minutes.

We ran the arrays completely flat, and they sounded excellent. We never needed to adjust the polarity via the provided polarity control switch, as everything lined up perfectly.

On another occasion, we flew the arrays from our 40×40 Total Structures concert roof, employing the KLA Series as audience fills for seating areas to the side of the roof. On this particular instance, we fed full concert signal to the speakers (for Paul Revere and the Raiders with The Grass Roots), inserting a Klark-Teknik Square ONE graphic EQ on the two signal paths. The boxes required very little EQ, yet with a pinch of correction, they sounded superb. Their proprietary fly frames made the set up go very quickly, and everything pinned together very nicely. With the KLA12s only weighing 55 lbs., and the 18 inch powered subs weighing only 100 lbs., this entire array weighed only 310 lbs. per side and required only one 20 amp circuit per array. These speakers are very easy to handle.


At first glance, the QSC KLA Series seems to violate the standard, “in-the-box” approach to line source speakers due to a severe bend in the array. But I must say that I am a fan of these speakers, as its EQ allows very smooth transitions from box to box, combining very nicely, with no appreciable phase disturbance or shading. This rig’s dispersion is very even and the frequency pattern control is very controllable, especially considering the short line that it is. 

Obviously, you will not be filling arenas with controlled patterns from this line, but that is not QSC’s intention. QSC created KLA to fill a void between the realm of large line arrays that can be controllable at much lower frequencies and capable of great throw, and no line array (or using conventional speaker boxes, which still have their applications). QSC has consistently-crafted quality products through the years, and this product is one of them. 

If you are in the market for a true “plug-and-play” application line array, look no further. I highly recommend the KLA Series speakers, as I recognize its components will provide years of roadworthy service, ranging from a complete standalone system and augmentation/area-fill speakers.

Will James, owner and chief owner of Atlantis Audio and Lighting, is a longstanding PAR Contributor.

Product Points

Pluses: Excellent sound; portable, lightweight, reliable; onboard electronics to augment the small LA format; nice fly frames

Minus: The surface of the boxes will scratch if handled roughly

The Score: Choosing KLA will provide years of roadworthy service as a standalone system, or as an augmentation/area fill speaker.

QSC Audio KLA Series in White: 

Belmont Church, Nashville

By Dan Wothke

Our church campus has a number of sound systems with a myriad of power amps, including some QSC Audio Products, yet I had never been given the opportunity to actually work with QSC speakers, so I jumped at the opportunity to check out this system.

Configured to meet Belmont Church’s needs, I was shipped four white KLA12 full-range speakers and two white KW181 subwoofers. The KLA Series does include a subwoofer (the KLA181, as reviewed by Will James above), but QSC’s KW181 subwoofer was best for us — a sub not intended for rigging; the KLA181 is equipped with special rigging points and hardware not necessary for my applications. 

I want to address the applicability of using this system for a house-of-worship or facility that requires a weekly setup—either because of building arrangement details, the existence of a satellite campus, or even just as a flexible system for various events and facilities. When reviewing components or an entire system for this application, I generally use three primary criteria: durability, ease of use, and sound quality. The KLA exceeded in all areas. 


KLA enclosures, made of an impact-resistant ABS material, handled well; everything I put them through in the normal process of setup proved the ABS and the cab’s steel grilles would protect their component-based and cosmetic attributes. 

KLA design is clearly well thought out; from handle placement to the color-coding of connectors on its rear panels; great design makes the least fun portion of set up go smoothly. On the bottom of the KLA12 is QSC’s Tilt-Direct pole mount slot, which is what I utilized in combination with standard speaker stands; it allowed me to adjust the height beyond what the supplied mounting pole allowed, and I felt they added more stability overall for the speakers.

Connecting two KLA12 speakers together was extremely simple thanks in large part to QSC’s SOLO Rigging System. This “no tools required” system allows connections in three easy steps, which are conveniently labeled on the side of the cabinet. With a push of a button, turn of a level and push of a slider, two KLA12s were securely locked together. As for the sub, I almost jumped for joy when I removed it from the box and found it shipped with casters mounted on its rear — no dolly necessary! The casters also serve as cable protection when the sub is in use, preventing someone from walking too close to the sub and accidentally snagging an XLR or powerCON connector. 

Up to five cabinets can be linked together in a rigging mode and two is the maximum on a standard stand. This is also the maximum they recommend when using the KW181 sub’s screw-in mounting pole; however, in our application, I felt better having them on their own stands. 

EQ’ing the system to adapt with each added KLA12 is handled internally, via a 5-way select switch on the rear. All I had to do is set the switch to “2” — representing the number of speakers — and the processors adapted the output to maximize coverage. The onboard processors also offer protection circuitry and preset EQ settings: External Sub, Normal and Deep for Low Frequency EQ adjustment. I tried our system in each setting with and without the sub; the best combination was set on External Sub (engaging the 100 Hz HPF). The KLA12s were more than adequate to handle low frequencies, and they even did a good job in the Deep setting (for when a subwoofer isn’t an option). In fact, I did a double-take on the sub when testing the Deep setting to confirm I had turned the sub down all of the way.

The Neutrik powerCON connectors were utilized on the 500W x 500W KLA12 and the 1000W KW181, and the system was shipped with the necessary jumpers to easily daisy-chain power. Since up to five speakers can be powered from one 120V outlet, my concerns were eased regarding the potential to pop a breaker. Total time from opening the boxes to hearing signal through a fully set-up system was under an hour. 

In Use

Finding the best fit for the KLA Series was my first task, as I wanted to experience them in the best possible situation. I ended up using them with one of our most grueling sound reinforcement applications, in the Youth building. A great youth service is paramount to the church, so I knew this would not be a cakewalk, tossing up some speakers and calling it a night. Yet the KLA system was nearly that easy. 

Our youth room is about 50- x 50-feet with 9-foot ceilings, so I used the pole mounted option with nine degrees of slope. Our youth band consists of drums, bass, keys, two electric guitars, acoustic guitar and three vocalists. Monitoring consisted of a combination of IEMs and wedges. Even without the sound system, the level in the room is moderately loud, so we rely heavily on speakers — not only to get levels comfortably above the stage volume, but to also provide sonic separation and natural reproduction, considering so much energy in the midrange.

This system consists of an Allen & Heath GL2400 analog mixer into a dbx DriveRack, which handles crossover and processing; I bypassed the dbx in order to hear the KLA/KW system handle the processing on its own. 

The youth services included 125+ kids in attendance, the band as described above, and a last-minute addition of four Audio-Technica wireless headset mics for a guest group. At first, I was concerned about the coverage; not vertically, as that space was limited, but horizontally, as each pair and sub were about 45 feet from each other. However, the coverage of the system proved to be thorough. Thanks to the 90 degrees of coverage, there was not a bad seat in the house.

From the downbeat of the first song, I found myself very confident with the KLA/KW combination. I bumped the subs up two level notches and, other than some minor EQ notches on the house (in the low-mid range) and slight bump in the 3k range, the system performed sans-processing. The KLA/KW rig made mixing very enjoyable, as it handled the full energy music with no problems. 


Often, a good gauge of speaker quality is how difficult they are to mix on. At no point throughout my use of the KLA/KW rig did I struggle with what I was hearing. If I didn’t like what I was hearing, it was more a reflection on what I was mixing than how the speakers sounded. The KLA components accurately reproduced whatever I threw at them, and the KW subwoofers supplied a constant low-end that provided the live and programmed music a heartbeat-bolstering pulse.

Sometimes revealing what a room could sound like with “the correct tools” is a double edged sword; the greatest challenge I now face is removing the KLA/KW rig, as the last thing I was told by the pastor was, “I want these speakers.” I would suspect that anyone who gets to work with this KLA Series would feel the same way. 

Dan Wothke is Media Director at Belmont Church of Music Row, Nashville. Reach him

Prices: $2,599, $2,049 and $1,399 street (KLA12, KLA181 and KW181, respectively)

Contact: QSC Audio Products |