Monitor Audio GX50 Loudspeaker

There’s an embarrassment of riches in the under-$2k loudspeaker category and, fortunately for me, I’ve been able to experience firsthand some of those bargains over the last few issues. For example, I recently wrote about a pair of compacts, real performers both, the three-way Polk Audio LSiM and the three-way KEF R-300 with concentric midrange/tweeter. On deck is the latest from Sonus faber, the Venere Model 1.5.

However, unique among these entrants and emblematic of the diversity in this segment is the Monitor Audio GX50. The smallest member in the GX Series, the GX50 is a two-way, stand-mount loudspeaker in a bass-reflex enclosure. Visually the GX50 strikes a premium pose from any angle. Aluminum trim rings circumscribe the drivers, and an inverted rubber surround rims the mid/bass. There are no visible screws or bolts to mar the effect (an access panel is cleverly hidden at the base of the speaker). The GX50 is a hybrid- driver design that features a 5.5″ mid/bass cone driver and a ribbon tweeter—the C-CAM ribbon transducer, which promises extension to 60kHz. It’s also worth noting that these are not one-size-fits-all units—each driver in the GX range has been specifically designed and optimized for the model it is used in, taking into account cabinet volume, desired bass extension, and efficiency. The crossover point of the GX50 is specified at a relatively low 2.3kHz, with a slope of 18dB per octave for both high- and low-pass sections.

Construction quality and cabinet finish are as good as they get in this price segment. Tolerances appear tight—literally seamless, in fact. But breaking with tradition the GX Series doesn’t secure the driver to the front baffle via a handful of screws. Rather, Monitor Audio employs an internal bolt-through method which increases cabinet rigidity back-to-front and maintains consistent tension around the driver periphery thus improving driver/baffle de-coupling in the bargain. The results speak (or don’t speak) for themselves. The cabinet was effectively invisible throughout my listening sessions. The terminal plate on the back panel is a die-cast alloy with high-quality bi-wire terminals. All internal parts are wired with Monitor’s Pureflow Silver cabling. The cabinet is 20mm-thick MDF throughout, with radial and cross-bracing techniques for rigidity and reduced cabinet coloration. The grilles affix magnetically, which preserves the clean, unbroken visuals of the front baffle.

Always interested in the challenges an engineer confronts in designing a coherent hybrid loudspeaker, I asked Monitor Audio’s technical director Dean Hartley for his take on the subject. He pointed out that development of the GX Series was an extension of Monitor’s work on the flagship Platinum Series in 2007, so the challenge of integrating moving coils and ribbons was not unfamiliar territory. Hartley added, “It’s still a bit tricky with passive crossovers to achieve perfect alignment with regards to time. Rather than designing the crossover in the frequency domain, which is what some designers do (and forget about the time), we concentrate on this first. We then look to see if we can ensure there is uniform frequency response…The C-CAM drivers we use have very lightweight moving assemblies that yield good overall transient response. We then have to make sure we use powerful motors and optimize the driver’s moving mass to yield the best transient response from the electro-mechanical section. We designed the ribbon tweeter to go down lower than most by using a special kind of flexible suspension system. This means we can drive it lower down and ensure that the integration with the mid/bass and also the off-axis response is better. Crossing a 5.5″ bass driver over to a ribbon at 4–5kHz is not practical, in our view. Of course, there is always going to be a small difference in transient response since the very low moving mass of the ribbon is impossible to perfectly match to a dynamic driver.”

Sonically I have to say, with small reservations, mission accomplished. The GX50 is a midrange-dominant loudspeaker that shines brilliantly on vocals, female especially as a cappella artist Laurel Massé proved repeatedly [Feather and Bone]. It relishes the delicacies of musical texture, air, and bloom. It’s very effective for its size in mid- and lower-level detail and dynamics with an engaging sense of “being there”—an attribute that encourages you want to keep listening. Tonally it can sound a little polite in the upper mids and there’s a bit of extra brilliance in the sibilance range, but the openness of the ribbon tweeter more than makes up for these relatively minor colorations. The ribbon is, as I’d expected, sweet, smooth, and superbly detailed in the transient realm. In the case of piano reproduction, it combines a sense of speed and edge detail at the commencement of a note with little to no impression of woolen overhang or smudging at the note’s conclusion. Although the GX50 is more a finesse loudspeaker than a headbanger’s dream, that’s not to say it completely lacks low-end punch; there’s genuine 60–70Hz capability here, and perceivably a bit more further down. Its small mid/bass driver is articulate and more than capable of holding its own on tracks from the Rutter Requiem [Reference Recordings], many of which feature the undertow of a pipe organ beneath the large chorus.

Driver integration was essentially very good with only some minor height-related lobing in my smaller listening room. Importantly there was little sense of any “hare and turtle” discontinuity between the ribbon and the cone transducers. My take away from this is that they are somewhat height sensitive, so establishing the correct height for the small cabinet is important. In my smallish room, the ideal was positioning them at ear level to the listening position which means a stand around 26″ tall. Monitor Audio offers a 24-incher for $495.

As previously alluded to, the GX50 tonal balance is on the lighter side. A track like “All The Roadrunning” is instructive in the way the GX50 captures the female voice more effectively than the deeper male voice. This duet features Emmylou Harris and Mark Knopfler, and it’s clear from the outset that the reproduction of the barrel-chested Knopfler’s vocal lacks the deeper resonances that characterize his dark, throaty voice. Yet Harris’ vocal on the next verse is unwaveringly consistent with previous experiences I’ve had with this track and a variety of loudspeakers. Similarly the full breadth of soundboard radiation from a grand piano is somewhat truncated; the rippling waves of ambience that fill a symphony hall and reside around specific images and sections are there, but the foundational weight that defines the soundstage and extends it to the rafters is reduced.

Bass extension is where compromises are most keenly felt in smaller speakers. Giving the listener a healthy impression of bass from a diminutive transducer is the stock and trade of talented engineers. And with only minor reservations, Monitor Audio effectively walks the GX50 along this fine line. Most of us are aware that the full weight of an orchestra requires either really large drivers or a whole bunch of smaller ones. Beyond the stout but small mid/bass cone, the GX50 has only its port to rely on, and there are moments when its upper-bass emphasis can be both a good and a not-so- good thing. It can effectively convey the beat and drive of a rock rhythm section or a bass-viol ostinato, but, especially at higher volumes, it can also sound a bit labored and one-note in character. To be fair, this is the way it is with almost all small compacts. Monitor Audio has struck a fair balance.

The Monitor Audio GX50 was very much at home in my small room. Bear in mind that at under a foot in height it does have ultimate SPL limitations, so don’t expect it to fill an auditorium. However, taken on its own terms, the GX50 is beguiling in its strengths and serious in its intentions, and with that ribbon tweeter adds a distinctively sweet flavor to the under-$2k category of loudspeakers.

SPECS & PRICING

Type: Two way bass-reflex compact
Drivers: C-CAM ribbon tweeter, 5.5″ mid/bass
Frequency response: 55Hz– 60kHz
Impedance: 8 ohms 
Sensitivity: 86dB 
Dimensions: 11.75″ x 6.75″ x 10.4″
Weight: 16.5 lbs. 
Price: $1795

KEVRO INTERNATIONAL 
902 McKay Road, Suite 4 
Pickering, Ontario, L1W 3X8 
(905) 428-2800 
monitoraudiousa.com