November 2005

PMC GB1 Loudspeakers

by Roger Kanno

Review Summary Sound "Like many minimonitors that feature a narrow front baffle, the GB1 exhibited excellent imaging properties, but with the extended bass response of a transmission-line design." "The soundstage produced by the GB1 was huge." "The bass did not go incredibly low, but it was tight and controlled down to the limits of the speaker." Features "The GB1 is a small, two-way floorstanding design that is ported at the bottom of the front baffle. It is essentially a minimonitor with the cabinet extending down to the floor that contains a transmission line." "The tweeter is a 27mm twin-chamber, ferrofluid-cooled, fabric-dome unit, and the 140mm bass/midrange driver features a cast-magnesium chassis. The crossover point is specified as 2kHz." Use "The GB1 sounded outstanding with all of the amplifiers I used, but I thought it sounded its best when mated to the least-expensive amplifier in the bunch, the three-channel Anthem MCA 30." Value "The GB1 is more expensive than some of the competition from North American manufacturers, but when you consider that it is a hand-crafted, real-wood-veneered loudspeaker from the UK, the price doesn’t seem out of line."

I have been on a steady diet of Canadian and US speakers for the past few years. However, my first pair of high-quality speakers was from Mission, an English company. There are currently many well-known British speaker manufacturers -- B&W, KEF and Monitor Audio -- that sell a lot of product in North America. One company that you may not be familiar with is PMC, whose acronym stands for Professional Monitor Company. As its name suggests, PMC produces professional monitor speakers with an impressive client list that includes recording studios and industry professionals all around the world. The company also has a complete line of consumer products designed for stereo and home-theater systems. I received a pair of PMC's smallest floorstanding home-audio speakers, the GB1, for this review. They are priced at $2250 USD a pair.

Until recently, PMC was distributed in North America by Bryston, the well-respected Canadian electronics manufacturer. However, the company has now set up its own distribution in the US, presumably in an attempt to increase its presence on this side of the Atlantic. Bryston still distributes PMC products in Canada and designs the amplifiers used in PMC subwoofers and active speakers.

Professional look

The most distinctive design feature of PMC speakers is their use of what the company calls an Advanced Transmission Line (ATL). A transmission line is basically a long, folded tube inside the enclosure that is ported outside and increases the bass response of the speaker. A properly designed transmission-line design will typically have better bass response than a traditionally ported or sealed-box speaker of the same dimensions. Transmission-line designs are not unique to PMC, but they are relatively rare, presumably due to the complexity of designing and manufacturing the intricate cabinets required to obtain good results.

The GB1 is a small, two-way floorstanding design that is ported at the bottom of the front baffle. It is essentially a minimonitor with the cabinet extending down to the floor that contains a transmission line. It is quite short for a floorstander and takes up very little floor space due to its compact dimensions. It is only 34 1/4"H x 6 1/4"W x 9 1/4"D, including its plinth and weighs a mere 23 pounds. The tweeter is a 27mm twin-chamber, ferrofluid-cooled, fabric-dome unit, and the 140mm bass/midrange driver features a cast-magnesium chassis. The crossover point is specified as 2kHz. Two sets of high-quality binding posts are provided for biwiring or biamping, and the grille is removable.

The cabinet is covered in high-quality cherry or black-ash real-wood veneer. The finish is not glossy, but the natural appearance will complement many décors. The review samples had a few knots in the finish, but they were otherwise built to a very high standard. Removable stabilizing plinths and spikes are included to provide a strong and steady base.

Professional setup

I used the GB1s in a couple of different systems. Sources consisted of an Arcam FMJ DV29 DVD-Audio/-Video player and a Pioneer Elite DV45A universal audio/video player. Amplification was provided by a Bel Canto eVo4 Gen II in both standard and bridged mono configurations and Arcam FMJ P7 and Anthem MCA 30 multichannel amplifiers. Control preamplification duties and sometimes digital-to-analog conversion were performed by either an Anthem Statement D1 or Arcam FMJ A8 surround-sound processor. Interconnects were Analysis Plus Solo Crystal Oval, and speaker cables were Analysis Plus Oval 9. Power cords were ESP A/V Power-Flow Pros that were plugged into an Empower EM2100 power conditioner. Speakers for comparison were two pairs from Paradigm: the Reference Studio 60 v.3 and Signature S8.

I placed the GB1s where the main speakers would normally be placed in my listening room: about six to seven feet apart, a couple of feet from the side walls and approximately three feet from the front wall. They were toed in slightly for the best possible imaging. For a short time during the review period they were also placed along the side wall of my room. Perhaps because of their front port, the GB1s sounded equally good placed only about a foot out from the wall.

Monitor sound

Other than the proprietary Advanced Transmission Line, the GB1 appears to be a relatively simple two-way design. Like many minimonitors that feature a narrow front baffle, the GB1 exhibited excellent imaging properties, but with the extended bass response of a transmission-line design. What surprised me wasn’t so much the quantity of the bass, but rather the quality of the low frequencies the diminutive GB1 was able to produce. The bass did not go incredibly low, but it was tight and controlled down to the limits of the speaker. The GB1 did not sound at all boomy. PMC claims a frequency response from 25kHz down to 29Hz, but I suspect that the output level drops significantly at the low-frequency extreme, so don’t expect the bass to shake the foundation of your house. I could push the GB1 past its limits -- it is relatively small speaker after all -- but up to that point, the entire frequency range remained focused and absolutely composed.

The soundstage produced by the GB1 was huge. Listening to Madonna’s Ray of Light [Maverick/Warner CDW 46847] provided a sonic picture that was extremely wide, but also had a good sense of height. The electronically synthesized instruments were laid out in a precise tapestry between the speakers with pinpoint imaging. They panned smoothly across the soundstage and oftentimes seemed to image outside the speakers. Vocals were always crisp and clear, and the bass on tracks like "Frozen" and "The Power of Good-Bye" was tight and articulate, which gave the music great pace. Even amongst the dense electronica of "The Power of Good-Bye," the GB1 was easily able to pick out the rich strumming of the acoustic guitar.

Straight-ahead rock'n'roll like the 20th-anniversary edition of Dire Strait’s Brothers in Arms [Vertigo 9871498], a hybrid SACD, also sounded amazing. There was plenty of snap to the snare drum, shaker and other percussion in the opening track, "So Far Away From Me," and the bass guitar growled with authority. Even though the GB1 lacked extreme bass, it was by no means a lean-sounding speaker. The guitar on "Walk of Life" had a rich, full sound reminiscent of a much larger speaker. Mark Knopfler’s raspy vocals also had plenty of body, but they were a little more forward than I am used to hearing. There was a very clear delineation between Knopfler’s voice and Sting’s backing vocals on the once-ubiquitous "Money for Nothing."

Acoustic recordings, such as most of the tracks on John Mellencamp’s greatest-hits CD, Words & Music [Island B000331110], also sounded very good. This is a somewhat unforgiving recording that can sound a bit harsh. The GB1 presented the songs just as they were without adding much of their own sound. "Pink Houses" was exceptionally clean and clear without becoming the least bit severe or objectionable. Percussion was again superb, and my favorite cut, "R.O.C.K. In the USA," was toe-tappingly good. I have never heard the cow bell sound better on my system, which is not something that I ever imagined myself saying.

I dug out my copy of the audiophile classic Don’t Smoke In Bed [Alert Z2 81020] by the Holly Cole Trio and found that vocals were also well served by the GB1. There was a lot of power and body behind Cole’s commanding vocals. Her closely miked voice can be challenging, but the GB1 did an exceptional job on "Don’t Let the Teardrops Rust Your Shining Heart" and "Tennessee Waltz." The presentation was again slightly forward, but there was very little sibilance and a relatively smooth sound overall. Playing Cole’s more recent release Shade [Alert 6152810392] revealed an almost flawless presentation. The percussion on "Heatwave" was striking, with the punchy wallop of the kick drum and the delicate sound of brushes framing Ms. Cole’s pristine vocals. All of the elements of the song were well defined, including a playful flute that floated effortlessly above the other instruments. "Almost Like Being In Love" had some of the most expressive and well-recorded female vocals I have heard and also had great pace. The GB1 precisely captured the slow, almost mournful vocals at the beginning of the song as well as the more upbeat and up-tempo lyrics and melody later on.

Even though I had several multichannel amplifiers on hand, I did not explore the GB1’s biamping capabilities, as I am sure that most people will use it in its standard configuration. The GB1 sounded outstanding with all of the amplifiers I used, but I thought it sounded its best when mated to the least-expensive amplifier in the bunch, the three-channel Anthem MCA 30. The Bel Canto eVo4 rated at 120Wpc and the Arcam FMJ P7 at 150Wpc are no slouches and both sounded excellent with the GB1s, but the additional power of the MCA 30 -- Anthem rates it at 190Wpc -- seemed to benefit the GB1s. The soundstage opened up a bit more, image outlines became a little more precise, and the bass went a little deeper and was slightly more defined. Granted, the MCA 30 could not match the wonderful sound of the eVo4 in bridged mono mode, where it is claimed to produce 400W and have the resolving power and finesse of a reference-quality amplifier. Nevertheless, there was a certain synergy between the GB1s and the reasonably priced MCA 30 that was exhilarating.

Company comparison

Even though I usually prefer to listen to much larger and more full-range speakers than the PMC GB1, I thoroughly enjoyed my time with them. That being said, they face a lot of competition at their price. Doug Schneider has reviewed several extremely high-quality bookshelf speakers, such as the PSB Platinum M2 ($1999 per pair) and the Paradigm Reference Signature S2 ($1900 to $2200 per pair), that he considers to be references for speaker performance at the $2000 price point. Tim Shea also reviewed the similarly priced Paradigm Reference Studio 100 v.3 ($2200 per pair), which he proclaimed "one of the greatest bargains in all of audio."

Although they are no longer in my system, I recently listened to a pair of Paradigm Reference Studio 60 v.3s ($1500 per pair), an exceptionally well-built three-way design. The Reference Studio 60 v.3 is much larger and heavier than the GB1, with a cabinet that is surprisingly deep considering its height and width. Both speakers had the same general level of performance, but the Paradigms definitely had the edge when it came to low bass. This is not surprising considering their much larger size, but the quality of the bass coming from the GB1 was as good, if not better than that of the Paradigm speaker. I am sure that some people will ultimately want more bass than the GB1 can deliver, but down to its limits, which were quite impressive considering the speaker's size, it was surprisingly tight and articulate for any speaker, let alone one of such small proportions.

The GB1 even compared favorably to my much more expensive Paradigm Reference Signature S8 speakers ($5600 to $6000 per pair). Disregarding the even more obvious disparity in bass capabilities between the GB1 and the much larger S8, the performance from the midrange on up was remarkably good. The highs of the S8 are what some would consider to be "silky smooth." The GB1 sounded less smooth in comparison, but did not become hard or etched. To get the near-perfect high frequencies provided by the S8, you usually have to spend a lot of money. The GB1 comes close for a lot less. Even instruments notorious for being difficult to reproduce, like the harmonica and fiddle, maintained their composure.

Although vocals sounded very good with the GB1, there was some coarseness when compared to the S8. The slight sibilance on the closely miked Don’t Smoke In Bed was tamed somewhat by the S8, and subtle inflections in Holly Cole’s voice were more obvious. This was less apparent with the more pristine vocal recordings like Shade, but the S8 still outperformed the GB1. The GB1 had the exceptional imaging qualities of a minimonitor, and cast a huge soundstage while seeming to disappear. When compared to the S8, images were less delicate and more "cut out." There was less air around instruments and voices, and the presentation was slightly flatter with less depth.

Although the imaging properties of the GB1 suffered in comparison to the S8, again, this type performance is usually reserved for a select group of extremely high-quality loudspeakers. The strengths of the GB1 are many and its weaknesses are few. It has amazingly articulate bass for such a tiny speaker. Its small size also means that it can be placed rather inconspicuously in most rooms. Compared to some of the larger speakers that I have had in my system, the GB1 was not particularly placement sensitive and sounded very good in a variety of locations. The GB1 is more expensive than some of the competition from North American manufacturers, but when you consider that it is a hand-crafted, real-wood-veneered loudspeaker from the UK, the price doesn’t seem out of line.

Conclusion

The PMC GB1 has excellent imaging characteristics, like those of a minimonitor, in addition to the added bass response of a floorstanding, transmission-line design. And, unlike many small speakers that try to extend their bass response at the expense of bass quality, the GB1 sounds as good in the low frequencies as it does throughout the entire frequency spectrum.

While speaker performance is paramount, the small size of the GB1 and its high-quality, understated wood-veneer finish make it very décor friendly. I can imagine these speakers finding a place in the interior-design plans of even the most fastidious audiophile. Add to this its flexibility in placement and the real-world usability, and the GB1 goes up another notch. Finally, good minimonitors will require a pair of stands that could cost several hundred dollars and still won’t have the bass response of the GB1.

When all of this is considered, the price of the GB1 becomes even more reasonable. It is a real-world audiophile speaker that makes few compromises and requires few excuses.

...Roger Kanno
roger@soundstage.com

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