Speaker Terminals
Most stereo receivers, amplifiers, and standard speakers have terminals on the back for connecting speaker wires. These terminals are either the spring clip or binding post type.
These terminals are also almost always color-coded for easy identification: The positive terminal (+) is typically red, while the negative terminal (-) is typically black. Note that some speakers are bi-wire capable, which means the red and black terminals come in pairs for a total of four connections.
Speaker Wire
Basic speaker wires have only two parts on each end: a positive (+) and a negative (-). Even though there are only two parts, there’s still a 50-50 chance of getting these connections wrong if you’re not careful. Swapping the positive and negative signals can seriously affect system performance, so it’s worth the time to double-check that these wires are correctly connected before powering up and testing the speakers.
While the terminals on the back of stereo equipment tend to be easily identified, the same cannot be said for speaker wires. This is often where confusion can occur because the labeling isn’t always obvious.
If a speaker wire doesn’t have a two-tone color scheme, look for a single stripe or dashed lines (these usually indicate the positive end) along one of the sides. If your wire has light-colored insulation, this stripe or dash may be dark. If the insulation is a dark color, the stripe or dash is more likely to be white.
If the speaker wire is clear or translucent, check for printed markings. You should see either positive (+) or negative (-) symbols, and sometimes text, to indicate polarity. If this labeling is difficult to read or identify, use tape to label the ends after you know which is which for quicker identification later. If you’re ever unsure and need to double-check, you can quickly test the speaker wire connection using an AA or AAA battery.
Types of Connectors
Speaker wires are most commonly bare, meaning you’ll need to use a wire stripper to expose the strands at the ends. Twist the bare wire strands tightly so that they stay together as a neat single twisted wire, whether your equipment uses spring clips or binding posts.
You can also find speaker wire with its own connectors, which can facilitate connections and help quickly identify polarity if they’re color-coded. Plus, you can install your own connectors if you don’t like to fumble around with bare wires. Purchase connectors separately to upgrade the tips of your speaker cables.
Pin connectors are used only with spring clip terminals. These pins are firm and easy to insert.
Banana plug and spade connectors are used only with binding posts. The banana plug inserts straight into the connector hole, while the spade connector stays secured in place once you tighten the post.
Connecting Receivers or Amplifiers
The positive speaker terminal (red) on the receiver or amplifier must be connected to the positive terminal on the speakers, and the same applies to the negative terminals on all the equipment. Technically, the color or labeling of the wires doesn’t matter as long as all the terminals match up. However, it’s usually best to follow the indicators to avoid potential confusion later.
When done correctly, speakers are said to be “in phase,” which means both speakers are operating the same way. However, if one of these connections ends up reversed (i.e., positive to negative instead of positive to positive), the speakers are considered “out of phase.” This situation can cause serious sound quality problems. It may not damage any components, but you will most likely hear the difference in output, such as:
Very thin, lean-sounding bass, poor subwoofer performance, or both. No discernable center image. A general sense that the system doesn’t sound right.
Of course, other issues can create similar sound problems, but an incorrect speaker phase is one of the most common mistakes when setting up a stereo system. Unfortunately, the Speaker phase setup is easy to overlook, especially if you’re dealing with a cluster of audio and video cables.
So, take your time to make sure that all speakers are in-phase: positive-to-positive (red-to-red) and negative-to-negative (black-to-black).
