Gershman speakers don’t look like other loudspeakers – but surprisingly often, other loudspeakers come to look like the Gershmans. Estalon’s striking XB caused a stir when it was first launched a few years ago – but followed firmly in the footsteps of the Gershman GAP-828, already an established model when it was reviewed way back in Issue 44. Likewise, at first glance, many people will mistake Gershman’s Grande Avant Garde for Wilson’s Sabrina – even though the original Avant Garde (sans base – which makes it look even more like the Sabrina) predated the Wilson model by almost two decades. It would be a mistake to read too much into these aesthetic coincidences, but they do illustrate something of the Gershmans’ individualistic and innovative streak. The company’s speakers break more than just aesthetic moulds – and have done so for years – with conspicuous musical success: success that has imbued them with long working lives and eventual acceptance (and even adoption) of their ‘different’ cabinet shapes and appearance.
These days, the Avant Garde’s tapered, truncated cabinet and sloping baffle looks almost familiar, so widely has it been imitated. It’s tempting to surmise that the distinctive oblong base added to create the Grande Avant Garde was a response to this general acceptance of the speaker’s looks, but in fact it simply illustrates another essential aspect of the Gershman credo, an attitude that might best be described as, ‘Never stop experimenting.’ Even so, this developmental imperative has always been harnessed to a stable core philosophy; for all their distinctive looks, acoustically and electrically, the different Gershman speakers share common and consistent DNA. What defines a Gershman? Extended low frequencies at the expense of overall efficiency and an extremely low system signature. As wildly different as they might look, one to another, all Gershman speakers have two things in common – inherent musicality underpinned by surprisingly deep bass. The Grande Avant Garde (or GAG) reviewed here stands a little under a metre tall (plus cones or feet) but its tapered cabinet appears smaller and less intrusive than that. The bottom of the cabinet proper is roughly 300mm square, the oblong base extending back behind it to almost twice that depth. Its form factor is neat and discrete – yet the specs quote a -3dB point of 22Hz and 89dB sensitivity. It’s the sort of number that has you assuming that the small enclosure contains a heavily equalised, active bass unit – probably pointing downwards. But actually, the GAG is an entirely passive design, its prodigious and clearly audible low-frequency prowess the result of clever acoustic design.
The driver line up in the GAG looks pretty standard, consisting of a (Gershman modified) 25mm Vifa soft-dome tweeter, a 90mm Audax carbon-fibre coned mid-range and a proprietary, 200mm aluminium bass unit. What’s not obvious is that the bass-driver is a Gershman-designed, dual magnet unit, making this a three-way speaker with a carefully tailored and potentially potent bottom end. The tapered main cabinets, with their divided, sharply sloping baffles arrive packed separately from the oblong bases. Their bottoms feature heavily rebated shoulders and these sit into a square opening in the top of the base, the junction sealed and decoupled by a neoprene gasket. Stability is aided by a large, circular weight set into the cabinet’s underside that also helps create a distributed vent between it and the air volume enclosed by the base element. Gershman describe this arrangement as the BCT (Back-wave Control Technology) and as the name suggests, along with the resistive line in the main bass enclosure, it is designed to trick the bass units into ‘seeing’ a larger volume than is actually there. The combination of tuned venting and the interior matrix constructed within the oblong base helps create a pressure differential between the main cabinet and the base. That draws the back-wave energy into the acoustically and mechanically separate base element where it is dissipated, reducing both intermodulation distortion and re-radiation through the cone.