JBL VRX900 Series
Apr 1, 2008 12:00 PM, By John McJunkin
Portable loudspeakers rank high.
It seems like every manufacturer in the world is making a powered speaker-on-a-stick solution these days, and many of them really do the trick for portable sound reinforcement. But there are certain applications for which a pair of plastic potato-shaped boxes just won't do the trick. And sure, you could get into stacks of boxes in order to achieve high quality, but then portability suffers. Is there a middle-of-the-road solution? There is indeed.
The JBL Professional VRX series loudspeakers have been available for a couple of years, and the company has recently introduced powered versions of this series, further enhancing portability. I test-drove a system consisting of two VRX918SP subwoofers, each supporting two VRX932LAP boxes. Frankly, I was thrilled.
The VRX932LAP is similar to other line-array loudspeakers, with one notable exception — we've grown accustomed to seeing symmetrical LF drivers on either side of the HF array in the middle of the box. Shave off one of those LF drivers, and you have the VRX932LAP. It employs the JBL Constant Curvature Line Array waveguide, which acoustically couples three HF drivers per box on a single line. When multiple boxes are used, the waveguide creates a continuous arc and keeps the distance between drivers equal — thus creating a constant curvature line source. Up to five boxes can be employed, and with vertical coverage of 15 degrees per box, a total of 75 degrees can be covered vertically. The horizontal coverage is 100 degrees wide.
One particularly unexpected feature is the ability to optimize coverage with the system's Array Configuration Selector (ACS), which is an amplitude shading mechanism. It allows you to either boost or cut each individual box's HF output (above approximately 1.5kHz) by 3dB — attenuating the HF output from the bottom loudspeakers closest to the front row of the audience — while simultaneously increasing HF output from the topmost boxes, dispersing more energy to the back of the room. Pretty clever and advanced for this type of system.
The other particularly clever feature of these loudspeakers is their integral rigging hardware, which facilitates the mechanical coupling of loudspeakers with hinged metal bars that are held in place with quick-release pins. JBL makes a line-array frame available, which along with the loudspeaker's built-in rigging hardware and dual-angle pole-mount socket, create a nice range of suspension options.
The VRX918SP is an ordinary subwoofer in appearance, roughly cube-shaped, with a healthy metal grille. It features the Drivepack DPC-2, developed in cooperation with Crown International. The “2” in the DPC-2 designation refers to Dual-Bridged Technology, the unique use of two discrete amplifiers to drive the two discrete voice-coils of the JBL Differential Drive woofer, maximizing power efficiency.
I can tell you that this mechanism provides full, round low end, but not just a pile of SPL — you can actually distinguish what kind of bass you're hearing. This subwoofer has a top-mounted receptacle intended to receive a SS4BK adjustable satellite-speaker pole. It can be used on the floor or flown with JBL line-array hardware. In addition to the previously mentioned ACS controls, the VRX932LAP has power and signal I/O; an attenuation knob; and peak, power, and signal indicator LEDs found on both subwoofer and MF/HF boxes. The VRX918SP's panel has crossover selector buttons that toggle insertion of the internal HF and determine its cutoff frequency to be either 80Hz or 120Hz.
I test-drove the system provided by JBL Professional in an application that included a male speaker, live music, and some multi-media. Again, I had a pair of VRX918SP subwoofers and each supported two VRX932LAPs.
Load-in and setup was really a two-person job, considering the size and weight of the subs. Additionally, once two VRX932LAPs are connected together with JBL's clever mechanism, you wind up with a pretty hefty construct, considering there are two 12in. LF drivers, amplifiers, and six HF drivers.
Actually, this rig is not all that heavy, but it still requires two people to hoist it onto the stand. Nevertheless, it sounds like a system that requires a full crew for load-in and setup. Connections were quite simple — feeding balanced line-level signals from front-of-house into the subs, which then fed the high-pass-filtered signal on to the other two daisy-chained boxes. JBL Professional has chosen to use Neutrik PowerCon connectors to get AC power to the amplifiers. In my mind, their similarity to Speakon audio connectors is a potential source for confusion, but as long as all technicians involved are aware of this, it shouldn't be a problem.
The application in which I test-drove the system normally uses a pair of JBL EON 15s, so I knew that the VRX rig would clearly deliver a lot more SPL. Otherwise, I simply fed the same unequalized (and lightly compressed) signal from FOH directly to the system.
The stereo image was the first thing to knock my socks off. Obviously, with its sophisticated waveguide and highly controlled dispersion pattern, left and right are very clearly delineated. Spectrally speaking, the entire audible spectrum was all there — and I do mean all there. The 18in. subwoofers are rated to 34Hz, and that's not an exaggeration. The LF drivers in the VRX932LAP boxes handled the low-mids and mids very nicely — and with two per side in this system, there was no strain in doing so. The HF drivers probably impressed me the most. The highs were crisp and clean, but not brittle.
In addition to the music and speech program material I heard, I also took the liberty of listening to a broad spectrum of music from CD as well — all great recordings. Rock fared very well, as did jazz, but the dynamic range of classical music really exposed the strength of this system. I listened to an excellent recording of Holst's The Planets at some pretty substantial SPLs, and considering my familiarity with that particular recording, I was truly blown away with the reproduction. These loudspeakers are not in the same league as JBL's Vertec series, but they stand on stilts head and shoulders above any other speaker-on-a-stick solution I've ever heard.
These loudspeakers deliver incredibly high quality considering their portability. They also facilitate some unexpectedly powerful means for sculpting the output for the environment. When factoring in price, it becomes pretty obvious that this system is well worth consideration. Indeed, if you need both high quality and portability, I haven't heard a better system.
Company: JBL Professional www.jblprofessional.com
Product: VRX900 series
Pros: Excellent balance of high quality with portability.
Cons: Speakon AC power scheme could be confusing.
Price: $3,199 (VRX932LAP); $2,249 (VRX918SP)
Frequency response: 75Hz to 20kHz (±3dB
Coverage pattern: 100×15 degrees
Maximum peak output: 136dB SPL at M
Internal amp output: 1750W peak, 875W continuous
System management: DSP limiters, mechanical/thermal protection
Frequency response: 34Hz to 120Hz (±3dB)
Maximum peak output: 126dB SPL at M
Internal amp putput: 1500W peak, 750W continuous
System management: DSP limiters, mechanical/thermal protection
John McJunkin is the principal of Avalon Podcasting in Chandler, Ariz. He has consulted in the development of studios and installations, and he provides high-quality podcast-production services.
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