This is what Celestion say:
Back in 1986 a new breed of hard rock player was on the rise. To meet the demands of the players and their increasingly ‘hot-rodded’ amplifiers, we set out to develop a modern speaker, capable of handling much more power and overdrive. To achieve this, we coupled our ‘H’ magnet (the closest in performance to Alnico) with a new cone and voice coil employing contemporary materials.
Our most revealing speaker, the Vintage 30 features enormously detailed and complex overtones, a warm low-end, a famously rich vocal mid-range and a beautifully detailed top-end. Used singly to reveal the complexities in hand- wired boutique amps, or in quartets for a wonderfully intricate vintage 3D crunch, the Vintage 30 sound has been captured on thousands of recordings from a diverse range of notable players including Slash, Steve Stevens and Peter Frampton.