PMC GB1 loudspeaker

 

 

 PMC GB1 loudspeaker

 

PMC, or the Professional Monitoring Company as it's known in some circles, built its reputation by supplying speakers to some of the best studios in the country and beyond. It makes some very serious models indeed and if you like your sound powerful yet resolute, it's one of the top brands on the market. PMC's more diminutive speakers therefore are also designed to be capable of delivering power, even when their main drivers are compact. The GB1 is PMC's least substantial floorstander to date and takes its design cues from big brothers such as the FB1 and OB1, models that quite literally tower over the cute little GB1.

Like all PMCs, the GB1 employs a transmission line to reinforce the bass output and this cabinet conceals a 2.4metre line between the back of the main driver and the opening at the bottom of the box. A transmission line (TL) works by using a long tapered tube which is lined with very specific damping materials (in this case 'custom foams'). The line absorbs all the frequencies produced by the bass unit apart from the very low frequencies which exit the vent in phase with the bass driver. A well designed TL can produce a full octave more bass than an identical driver in a conventional sealed or reflex enclosure. The drive unit in the GB1, which delivers both front and rear energy for this purpose, has a 140mm cast chassis with a 95mm doped paper cone. Thanks to the TL this compact driver is claimed to deliver bass down to 29Hz (albeit 6dB down) which is truly rumblicious country. At the other end of the scale, its 27mm fabric dome high frequency unit claims to stretch up to 25kHz, which is pretty high for a soft dome.

The dinky cabinet is made up of CNC cut 17mm Medite panels with the TL labyrinth in 12mm, the latter forming substantial bracing for the whole box. Because the footprint of this speaker is so small there is a plinth which bolts onto the base and extends its stance by around 50mm, this provides spike sockets so that you can 'nail' the thing into the floor. Should that lack appeal you can go spikeless or use coins or similar to avoid floor punctures.

The crossover is accessed by twin terminals for easy bi-wiring and uses steep roll-offs to enable high power handling and 'superior' phase characteristics. Components are connected using high silver content solder and are tolerance-matched for consistency.

Performance
Listening commenced using the Arcam Solo CD receiver in the driving seat, its 50 watts per channel are not quite up to kicking out the hardcore jams but the combination proved well suited in all but the level department. In its hands the GB1 timed nicely thanks to the tight but extended bass and an enthusiastic midband. Love Hater from Outkast's The Love Below album was a little 'tinselly' at higher frequencies but this is offset to an extent by the weighty bottom end, and while this is a full-on recording it does lack sophistication in the treble.

With more powerful amplification (Gamut's 200-watt D200) you start to get a better idea of what this speaker is all about, which is producing a remarkably grunty sound for a mini floorstander. Very few small speakers get anywhere near this depth and control of bass and it's this underpinning of the sound that encourages you to keep turning up the volume. There is inevitably a limit, drivers of this size can't go all the way, but it's a high limit and a lot of fun with heavyweight tracks. It's safe to say the GB1s like to play loud, and while they don't have quite the dynamics of bigger speakers when doing so, they are generally happy to kick arse for as long as you want to take it.

They do plenty of subtle things as well, imaging for instance varies to reflect the recording and although the sense of 'air' is not that great they are capable of drumming up a nice big image. The advantage of small, stiff cabinets like these is that they don't join in very much and as a result when you close your eyes it's difficult to place the speakers, recording quality permitting.

If anything the treble can seem a little hard and cymbals are rather splashy and unnatural as a result, though they do reveal the advantages wrought by adding a Marigo mat to a Resolution Audio CD player in this department, so there's plenty of transparency there. You can easily hear that this mat improved the intelligibility of sticks on hi-hat and increases the contrast between instruments.

 

 

Price: £1,145
Size (WxHxD): 16x87x23cm (plus plinth)
Weight: 10.5kg
Sensitivity: 87dB/w/m
Impedance: 8ohms nominal/6ohms minimum
Drive units: mid/bass - doped 140mm pulp cone, treble - 27mm fabric dome
Plus points: A powerful speaker with great bass extension for its size and a revealing midrange. A lot of fun too
Minus points: Slight sense of compression compared to bigger designs, and a shortage of 'air' at high frequencies

 

 

 

Price: £1,145 Website: www.arcam.co.uk Size (WxHxD): 16x87x23cm (plus plinth) Weight: 10.5kg Sensitivity: 87dB/w/m Impedance: 8ohms nominal/6ohms minimum Drive units: mid/bass - doped 140mm pulp cone, treble - 27mm fabric dome Plus points: A powerful speaker with great bass extension for its size and a revealing midrange. A lot of fun too Minus points: Slight sense of compression compared to bigger designs, and a shortage of 'air' at high frequencies