How To Measure Speaker Wire Size. Switch on the meter and set it to measure ohms on the lowest range. However, if you’d like a simplified answer here’s a chart to fit the needs of most people.
To measure the impedance of a speaker you’ll need a multimeter or a dedicated resistance meter. Step 1, check the label for a nominal impedance rating. You can use a common wire stripper, however, to determine the diameter or the gauge size of the wires.
Simplified speaker wire size chart
In the mobile audio world, it helps to think about the size of car speakers as more of a category than an actual size. This nominal impedance rating (usually 4, 8, or 16 ohms) is an estimate of the minimum impedance for typical audio ranges. Measure the diameter of wires with precision scientific vernier calipers by enclosing the caliper jaws on either side of a wire and checking the scale for a measurement. This is why the thinest wire has the largest number.