Inakustik Reference LS-1102

A large cross-section alone does not make a good speaker cable: the way the copper is distributed matters too. Here, each polarity is split between three conductors that alternate with those of the opposite polarity, inside a sheath measuring 10 mm in diameter. Sold cut to length, it can be ordered to the exact length your installation requires. It is the most advanced model in in-akustik’s Referenz series sold by the metre, manufactured in Germany.

Three conductors per polarity, alternating

The LS-1102 combines six conductors of 1.95 mm² each. Three carry the signal, and three provide the return path, giving a cross-section of 5.85 mm² per pole. Their arrangement follows a triple symmetry: around the cable’s axis, each positive conductor has negative conductors as its neighbours.

This alternating arrangement targets inductance. Between the outgoing and return current paths, every cable forms a loop, and this loop generates a magnetic field that impedes the signal increasingly as frequency rises. When the two polarities are close together and interwoven, their fields cancel each other out and inductance decreases. Over a few metres, the effect remains subtle; it becomes more significant over long runs and with speakers whose impedance drops low in the treble. Bringing the polarities closer together comes at a cost, however: the conductors face each other over a larger surface area, which increases the cable’s capacitance. The insulation’s role is to keep it in check.

Foamed insulation to keep capacitance in check

Each conductor is sheathed in two-layer DUO-PE II insulation. The first layer is foamed polyethylene: foaming traps air in the material, and air has the lowest dielectric constant achievable in a cable. Less insulating material between the conductors means lower capacitance, so the cable stores less energy in the manner of a small capacitor. A layer of solid polyethylene covers the more fragile foam and protects it against crushing. A polyethylene mesh sheath covers the entire assembly.

Most transistor amplifiers are unaffected by the capacitance of a typical speaker cable. Some designs with very wide bandwidth or low negative feedback are more sensitive to it, and it is with these that the compromise between low inductance and controlled capacitance is most useful.

Strands arranged layer by layer

Each of the six conductors contains 37 high-purity copper strands twisted concentrically: one central strand, followed by successive layers of 6, 12 and 18 strands, each in a defined position. In conventional stranding, the strands cross randomly along the entire length, and their contact points vary from one place to another. The concentric structure fixes these contacts and provides a uniform conductor from end to end.

The skin effect, the tendency of current to concentrate at the surface of a conductor, remains weak at audio frequencies for strands of this diameter. The main benefit of concentric stranding lies in the conductor’s mechanical and electrical consistency along the entire cut length.

A cross-section that goes the distance

With 5.85 mm² per pole, resistance is around 0.006 ohm per metre, counting both the outgoing and return paths. Over a 10-metre connection, this represents approximately 0.06 ohm, barely 1.5% of the impedance of a 4-ohm speaker. A typical 2.5 mm² cable reaches nearly 0.14 ohm over the same distance.

This resistance adds to that of the amplifier and reduces its ability to restrain the movement of the bass drivers, known as the damping factor. The lower it remains, the better the bass is controlled. The LS-1102 is suited to situations where the speakers are far from the amplifier (rear channels in a home cinema system, a large room with the electronics placed to one side), or where their impedance drops sharply in the bass. For two 8-ohm bookshelf speakers two metres from the amplifier, this cross-section far exceeds what is needed.

Cutting, stripping and terminations

Sold by the metre, the LS-1102 is cut into two identical lengths for the left and right channels, even if one speaker is closer: both channels retain the same electrical behaviour. At each end, the three conductors of the same polarity are grouped and twisted together before connection.

Once grouped, each pole’s cross-section fits into most screw terminals as bare wire. For banana plugs or spade connectors, models accepting at least 6 mm² are required; the rhodium-plated versions in in-akustik’s Referenz range accommodate up to 10 mm². The 10 mm diameter and firm sheath require a generous bend radius and some space behind the furniture or speaker, and the cable’s weight puts strain on the terminals when it hangs vertically: it is best to let it rest on the floor before making the connection.

Its place in the Referenz series sold by the metre

The series starts with the LS-502, two twisted 2.97 mm² conductors within an 8.5 mm diameter. The LS-602 moves up to four 1.87 mm² conductors in double symmetry (9 mm), followed by the LS-1002 with four 2.97 mm² conductors (10 mm). The LS-1002 offers almost the same cross-section per pole as the LS-1102, 5.94 mm² versus 5.85 mm²: choosing the LS-1102 therefore means opting for triple symmetry and lower inductance, not more copper. Above these, the Referenz Micro AIR and AIR series use a different principle and insulate the conductors primarily with air.

Technical Specifications

Structure

• Hexa CC-195 design (6 × 1.95 mm²)
• Symmetrical 3-conductor structure
• 37 strands per conductor, concentrically twisted

Insulation

• Double polyethylene (DUO-PE II) around each conductor
• Polyethylene (PE) anti-vibration outer sheath

Performance

• Induction arm for uniform reproduction

Commercialization

• Sold by the meter