Ordinary 12-gauge zip cord is Rod Elliott’s (ESP) benchmark speaker lead for domestic runs. His simulations of one amp and one speaker model put the audible stakes in fractions of a decibel — not in cable brand stories.

Short answer

ESP (“Loudspeaker Cable Characteristic Impedance”) treats 12-gauge zip as the standard against which other constructions are judged: cheap, easy, and electrically benign for a typical 4 m (about 13 ft) domestic run. ESP’s cables article adds that speaker cables can sound different with a given amp and speaker even when they are well designed and of reasonable gauge — and that very thin or extremely silly combinations will always do something to the sound, rarely good.

What ESP’s simulations show (4 m runs)

All figures below are ESP’s simulations of a 4 m length into his modeled two-way speaker, driven by one simulated solid-state amp.

  • 12-gauge zip: total variation about 0.13 dB, from the peak at the woofer’s resonance down to 20 kHz; high-frequency rolloff between 10 kHz and 20 kHz about 0.1 dB.
  • Australian “figure-8” lamp cable (0.75 mm² per conductor in ESP’s test; NIST’s copper wire tables list 18 AWG at 0.823 mm²): total variation about 0.31 dB, and still less than 0.5 dB down at 20 kHz.
  • None of these cables is 1 dB down on midband level at any frequency up to 20 kHz (ESP’s conclusion line).

ESP notes that “inductance will have a greater effect if the load is 4Ω (or less)” (his Table 3 lists the rolloff for 8 Ω and 4 Ω loads). That is why speaker impedance curves matter when you size a run to a low-impedance box.

Resistance and length

At audio frequencies ESP treats speaker cables as resistance, inductance and capacitance — not as RF transmission lines. In ESP’s table, the thinner figure-8 cable has more than three times the resistance per meter of 12-gauge zip, and in his response plots resistance dominates at low frequencies. A longer run adds more of it. His “very thin or extremely silly combinations” line is the case to avoid. For reference, NIST’s copper wire tables (Handbook 100, at 20 °C) list 12 AWG at 3.31 mm² and 5.21 Ω per kilometer of conductor, 14 AWG at 2.08 mm² and 8.28 Ω/km, 16 AWG at 1.31 mm² and 13.2 Ω/km, and 18 AWG at 0.823 mm² and 21.0 Ω/km. A speaker run has two conductors, so double the length when you add it up.

Exotic cables

ESP: constructions with very low inductance and high capacitance can upset some amplifiers (oscillation risk). He does not recommend chasing premium brand cables for audible gains his simulations do not show.

Hook-up

How to wire multiple drivers: series and parallel. Matching the amp: matching amp power to DIY speakers. Parts desk: Parts & kits hub.