The speaker cable model Type 4 was first introduced about 1983. It wasn’t the prettiest cable, but the performance advantage of its polypropylene insulation was dramatic and much appreciated. Several evolutionary steps later, the current version of Type 4 was introduced in 1995—a design whose foundation is so well balanced that it hasn’t changed since then—and still isn’t changing.

Types 5 Low-Distortion & Low-Noise speaker cable is essentially Type 4 with better metal, and with conductors that are a little farther apart, reducing interaction between adjacent conductors by 35%.
 
Solid Perfect-Surface+ Sonic-Signature Conductors
Carbon-Loading and Direction-Controlled Conductors
Star-Quad Geometry
 
SOLID PERFECT-SURFACE COPPER+/LONG-GRAIN COPPER SONIC-SIGNATURE CONDUCTORS
A finessed combination of grainless-sounding Perfect-Surface Copper+ Sonic-Signature conductors, plus Long-Grain Copper, enable a smooth and natural "lack-of-character."
SOLID CONDUCTORS
Eliminate harshness and confusion due to strand-interaction.
NOISE-DISSIPATION
Carbon-Loading and Direction-Controlled conductors provide effective Noise-Dissipation, minimizing noise modulation and amplifier distortion.
STAR-QUAD GEOMETRY
Balanced Star-Quad Geometry reduces time-smearing while preserving dynamics, and clarity.