Decks with short spindles where 5mm would cause problems. They are commonly found on decks with felt mats about 3mm thick. Achromat 3mm: Why the 3mm, then? - Arms with no VTA (Rega) are awkward to adjust. In tests the 5mm consistently betters the 3mm mat. Achromat 5mm: This is the standard recommended thickness. In use… Two thicknesses are available: 3mm and 5mm.
It has become the mat of choice for LP12 owners and also Technics SL1200 turntables. No wonder Achromat is the World’s top selling mat. And of course there are the testimonials from happy customers. In 2009 Achromat came top in a mat comparison in HiFi Choice and then went on to win the Gold Award for Accessory against all comers. Longer term listening allows subtle nuances as well as greater bass intelligibility to be appreciated. No other mat is like it and all it takes is a simple A-B comparison to demonstrate the differences against other supports. In this way, Achromat acts like a considerably thicker mat. Millions of tiny bubbles within create complex pathways and that’s where the energy gets lost as heat. But it is only 3-5mm thick and this is where the science kicks in. Can we prevent his reflection? Achromat is the ideal material to absorb energy from the record. When there is a material change (the record sitting on a felt mat, say, these waves are reflected and energy reflected from the bottom of the record (a mere 2mm thick) is sensed by the stylus and heard as colouration. This means your groove wall is not so much caressed but more akin to being pummelled by a road hammer creating travelling shock waves.
Theory: The stylus accelerates at up to 20,000g.