Turntables are literally precision analogue measuring instruments using the cartridge stylus as the sensor. The needle traces the groove, its relative deflection causing the coils/magnets in the cartridge to transducer this mechanical energy into electrical energy, which is duly amplified and converted back into mechanical energy by your loudspeaker voice coils. This is the theory, at least, but in practice the stylus also picks up vibrations from the loudspeaker sound waves via the turntable itself. Indeed, the turntable itself acts as a kind of microphone, capturing all manner of ambient energy and feeding it back into the system (thus muddying the sound). This is why isolation is all important, as is suspension design and also the mechanical ‘quietness’ of the platter (which is the closest point of contact between the turntable and the stylus). Trouble is, a great many decks still use metal platters (usually mazak, cheap kind of aluminium alloy) which tend to ring like a bell when struck with a fingernail. Manufacturers attempt to damp this ringing with, variously, felt, rubber or acrylic mats, but there’s always room for improvement. Sound Dead Steel’s platter mat consists of two aluminium disks of differing thicknesses, with a layer of polymer sandwiched between, which is then balanced and black powder coated. It’s simple to use; you just place the disk on your existing platter, and then (where applicable) put the existing mat on top. Because the disc is only 2mm thick, it shouldn’t upset the arms Vertical Tracking Angle (VTA) too much, but if it does, then obviously you’ll have to adjust the arm height slightly. In decks with no mat (such as the Michell GyroDec), then the platter mat can go straight on the top.
Placing the mat on any deck’s platter is quit amazing; flick the circumference of the platter without the SDS mat and it ‘tings’ (especially if it’s metal, or glass rather than acrylic) – but then add the SDS mat and repeat the exercise and it’s far more akin to a dull ‘thunk’. This shows how the mat takes so much mechanical energy out of the platter, deadening it down more effectively than any rubber, felt, glass, cork or sorbothane mat I’ve ever tried. If the ‘finger test’ proves its mechanical efficacy, then you should hear the difference it makes when records are spun in anger. There’s a dramatic reduction in clang in the midband, causing a real drop in nasal colouration. The whole soundstage opens out (front to back, left to right), the tonality of the instruments is better discernible, the bass appears tighter and more fluid and the treble smoother and cleaner. Even with a turntable with excellent disc support such as a Michell GyroDec, the SDS mat makes an obvious difference. Taking it a good way towards Orbe performance – but with a mazak classic Japanese Direct Drive, it’s night and day; the SDS mat making the deck sound obviously less bright yet faster and more incisive too. This is the best turntable mat I’ve yet heard. It may not work with every deck equally and may require some experimentation (rubber mat on or off, arm VTA up or same etc,), but I’ve tried it on a wide variety of decks (budget, high end, belt drive and direct) and every time I’ve wanted to keep it on rather than reverting back to stock. At well under £100, it’s a bargain.
