Of course, every loudspeaker manufacturer claims that their speaker is different, unique and superior. But in Göbel’s case, those claims are a whole lot more credible while the superiority of the results speaks for itself. The company started life by designing and building an innovative, almost full-range, bending wave, flat-diaphragm drive-unit roughly the size of an iPad, a discipline that demands considerable understanding of materials and controlled resonant behaviour in a flat surface. That driver and the speakers it spawned, still exist – and still have their die-hard advocates. On the surface, the huge, multi-driver, ported cabinet Divins couldn’t be more different. But the cabinets and proprietary drivers are the result of exactly the same knowledge base. If a drive-unit depends on maximising even, wide-bandwidth output while eliminating unwanted resonance, designing a speaker cabinet involves minimising the self-same things: the same knowledge base, techniques and understanding, just applied in the opposite direction. The results are clear to see once you dig below the surface of the Divin speakers.
If we start with the drivers, the tweeter is a horn-loaded Heil AMT, a legendary driver but one that designers have always struggled to mate to conventional, dynamic bass or mid drivers. In the Majestic, Göbel attacks the problem in two ways: It uses the horn loading to help extend the output of the AMT down to 1,600Hz, where it’s mated to a pair of 8” midrange drivers, using shallow 6dB slopes. The midrange drivers run down to 120Hz where they crossover to the 18” bass units, again with a shallow 6dB slope, the whole forming a symmetrical D’Appolito array. The drivers use low-mass, cellulose cones mated to large diameter, ultra-light, fibre-glass voice-coil formers to help avoid thermal compression and variation. Instead of terminating the diaphragms with lossy, rubber surrounds, the company employs pleated fabric in order to maximise low-level resolution and driver efficiency. Resonant behaviour is controlled through the use of highly evolved diaphragms, specially developed coatings, dust cap geometries and materials, a direct development of the approach and techniques used in the bending wave driver. The result is drive units that might look conventional but employ distinctly different approaches to achieve a very specific end.
The cabinet accounts for most of the speaker’s enormous weight. As described above, it is separated into three, discrete enclosures, isolated from each other by composite cork/rubber layers placed between them, helping reduce intermodulation distortion. Each enclosure is constructed from 40mm thick constrained layer panels, with multiple layers of melamine resin material bonded together using soft-setting polyurethane glue. Careful calculation of dimensions and bracing creates an enclosure that is able to absorb considerable energy, converting it to low-level, broad-band mechanical output, with none of the peaks or spikes that afflict most cabinets. Individual, machined aluminium baffles are mounted to the front of the enclosures ensuring a precise and solid mechanical reference for the drivers. Combine the enclosure and the aluminium elements and the midrange drivers are anchored to an 11cm/over 4” thick baffle. But controlling resonance and mechanical feedback in the cabinet is only one half of the story. The other half is concerned with the behaviour of the enclosed air-mass.
