Spectra Dynamics is a small Welsh company specialising in the production of a rather interesting, soft polyurethane material, which is very dense, very flexible, and exhibits a high degree of self‑damping due to its long‑chain molecular structure. The company already manufactures a range of products based on this material, most of which are aimed specifically at the hi‑fi market, but some of them seem equally applicable to the recording studio.
Spectra Dynamics first contacted me after reading my suggestion of mounting monitor speakers on blobs of Blu‑Tak, whereupon they informed me that they sold a material which would provide greater isolation, and which wouldn't get squashed flat with age. I was intrigued enough to take a look. The product in question consists of a set of four huge stick‑on feet (around 5cm in diameter), called Foculpods, normally sold to hi‑fi users to isolate their CD players and record decks from vibration. Foculpods do seem to provide a respectable amount of isolation, and they have a very tacky feel, which makes them incredibly non‑slip.
Apparently, the material works best when it is under compression, so speaker mounting seems to utilise its properties to their greatest advantage, but you can also buy sheets or blocks of the stuff to use in room construction. It is rather more expensive than neoprene, but in certain strategic situations, the extra cost may well be justified.
Another application for the material is treating the insides of loudspeaker cabinets, and although I haven't tried this on any of my own monitors yet, there are various testimonials to indicate that it is often beneficial — or there is at least an audible difference. Essentially, the inside surfaces of the cabinet are treated by fixing quarter‑inch thick Deflex panels, which have a Fresnel lens‑style ribbing moulded on to their surface. My calculations suggest the lens contour will have little, or no effect in refracting anything other than the very highest frequencies, but the surface area will be increased, thus helping absorption. The manufacturers claim that the material works by reducing the amount of reflected energy redirected back through the bass driver's cone. Contoured pieces are also available for treating the inside corners of the cabinet, but again, I can't say at this stage whether this makes a significant difference.
After experimenting with the Spectra Dynamics polymer, I feel that it has a number of beneficial uses, including loudspeaker isolation, isolating guitar amps from the floor (try four Foculpods on the amp, and then stand this on a small paving slab), studio construction, damping resonant panels, and treating equipment where there is a tendency for the lid to vibrate in sympathy with the mains transformer. You could even try isolating DAT, CD, DCC, or ADAT/DA88 recorders in any environments where there is a lot of structural vibration.
You really have to handle this material to appreciate how dense and non‑slip it is — its texture approaches that of the dead rubber bats you can get from joke shops! The way that it absorbs energy is explained by simple physics — it is not just another 'snake‑oil' product spawned by the hi‑fi business, but equally, it isn't going to miraculously solve all your problems either. Ultimately, it's just a new material, and like any material, it has to be used in the right context to produce worthwhile results. Even so, the more you think about it, the more applications you can find for it.