QSC AP5122m Speaker & GP118sw Sub Review
Apr 9, 2013 2:55 PM, Reviewer: John McJunkin
A multipurpose speaker with strong SPL.
Typical applications for small to midsize speakers, such as seminars, conferences, meetings, clubs and other venues, often call for specialty products. Trying to accomplish that goal with the wrong tools can get complicated, messy, and maybe even impossible. However, there are certain scenarios that are more forgiving, allowing for a number of different tasks to be accomplished with the same speaker as long as it’s designed for multiple purposes.
QSC’s AP5122m is such a speaker—the “m” stands for multipurpose. For club or amusement park applications it can be flown from a truss; it can be pole-mounted or flown, or simply placed on stage in a front-of-house role; it can also be tilted on its back and used as a floor wedge monitor. It works in a number of ways while delivering substantial SPL with excellent fidelity. I evaluated a pair, along with a QSC GP118sw subwoofer.
The AP5122m derives from QSC’s AP5122, and is nearly, but not exactly the same. The original speaker is a trapezoidal shape, which allows the speaker to be placed on the floor as a wedge. I found its design very clean, with nothing flashy or gaudy. The speaker is available in black, and that color covers the entirety of the enclosure, including the grille, 11 M-10 mounting points, and other hardware visible on the surface. QSC deliberately chose to forego a logo badge on the enclosure, rending a more aesthetically useful and pleasant appearance. Another unique feature of the cabinet’s appearance is its slightly concave front grille. I’ve seen speaker grilles with rounded edges, but this is the first I’ve seen with a slight inward rounding. It only dips inward along the vertical axis of the speaker, like a very subtle boat shape. It has aesthetically pleasing lines that would look good in virtually any install environment.
Moving to the technical domain, the QSC Acoustic Performance (AP) series was developed to deliver excellent fidelity at high SPLs. The factor that probably contributes more to excellent fidelity than any other is QSC’s unique combination of passive crossover and physical waveguide implementation of Directivity Matched Transition (DMT), a design approach that matches LF and HF coverage in the cross-over region. All horn-loaded high-frequency drivers deliver sound through a waveguide of some kind in order to arrive at an appropriate and useful dispersion pattern, but the waveguide developed for the AP series takes more than just broadband dispersion into account; it actually maintains a controlled 90-degree “axisymmetric” pattern that delivers energy nearly equally across the frequency spectrum. Looking at both the vertical and horizontal polar plots of energy dispersion, the patterns exhibit the natural and unavoidable increase in directionality as frequency increases, but evenly so. The contours of both axes’ plots are similar, and smoothly transition from more omnidirectional in the low mids to a nice cardioid above 8kHz. This looks natural on paper, and sounds natural to the ear as well.
As to the delivery of high SPLs with these speakers, QSC deployed a 12in. low-frequency driver with a 4in. voice coil. Even the high-frequency compression driver has a 3in. voice coil. QSC rates the broadband maximum SPL at 122dB continuous, 128dB peak at 1 meter. After listening to these speakers, I can tell you that they deliver every bit of that. Considering their size, these are very loud speakers. At high SPLs like this, distortion is always a concern, but I did not hear any serious deal-breaking distortion even at top-of-scale SPL. QSC publishes a frequency response of 55dB to 18kHz (-10dB). This sounds honest to my ear, presuming that the 0dB crossing in the low end is probably between 65Hz and 70Hz, give or take. The result is that if your application requires deep, full, Earthy bass, you’ll need to specify a subwoofer, and QSC recommends pairing it with its GP218 or GP118 units. The system I evaluated comprised a stereo pair of AP5122m speakers and a single GP118sw—a 2.1 satellite arrangement.
When I spoke with QSC’s David Fuller about this loudspeaker series, he said these subwoofers the best he had ever heard, and while I may not elevate them into the highbrow world of studio-grade subs, the GP118 I evaluated sounded very good. When coupled with the pair of AP5122m speakers, I heard the full, broad spectrum of human hearing, all the way down in to the deep bass that’s felt as much as heard. I listened to a wide array of musical styles and spoken word with these speakers (powered by a pair of QSC amplifiers intended to match up properly with the speakers in terms of power and impedance). They sound good and as promoted by QSC, quite natural. Not only is the response smooth through the crossover point, I also didn’t hear hot spots at distinct frequencies as I moved around the dispersion pattern. The energy was evenly dispersed over the frequency range, at least as evenly as nature will allow. It’s the transition throughout the 90-degree dispersion pattern that is even and smooth to the ear.
I did not see a frequency response plot for the AP5122m, but QSC’s plot for the regular (and similar) AP5122 speaker is quite flat, and the manufacturer spells it out: that flatness results, at least partially, from its recommended processing. I did not apply any external processing, but I relied on the internal crossover at 950Hz. Indeed, the multipurpose version of the AP5122 sounded flat to my ear—no honky midrange bump or exaggerated highs. The highs also sounded nice and creamy to me, which was frankly a bit of a surprise considering a high-power large voice coil compression driver choice that could almost be described as excessive. Nevertheless, it does sound very good.
The controlled energy dispersion across the spectrum and throughout the pattern yields a clear, distinct stereo image. And as I said, these speakers are plenty loud. Their 15-ply Baltic birch construction also makes them very heavy for their size: 63lbs. As a frequent user of self-powered speaker-on-a-stick solutions that continue to amaze with their dwindling weight, I was actually startled when I first picked up an AP5122m. But a sturdy, unflexing enclosure makes an audible difference, and can be worth the weight.
Pros: Even energy dispersion across spectrum and throughout dispersion pattern.
Cons: Baltic birch construction rends cabinets quite heavy.
Applications: Wedge monitors, performance spaces, worship, dance clubs, theme park
Price: $1,582 (AP5122m); $1,332 (GP118sw)
Frequency Response (-10dB): 55Hz – 18kHz
Power Capacity: 550W/60V continuous
System Sensitivity: 95dB, 1W@1M
Coverage Angle: 90º Axisymmetric
Directivity Factor: 6.0
Directivity Index: 7.8
Recommended Crossover: 950Hz, 48dB/octave (in active mode)
Maximum Rated SPL (Passive): 122dB@1M continuous, 128dB@1M peak
Rated Impedance: 8Ω
Input Connector: Dual NL4 Speakon connectors
Grille: 16-gauge powder coated steel
Dimensions (HxWxD): 26”x15”x11.3”
Net Weight: 63lbs.
John McJunkin is the principal of Avalon Podcasting in Chandler, Ariz., and produces and co-hosts a top-rated morning radio talk show in Phoenix. He has consulted in the development of studios and installations and provides high-quality podcast and voice production services.
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