Wiring the Left and Right
If you have a component system with a separate streaming device, DVD, CD player, or turntable, you’ll typically connect those to your amp or pre-amp via RCA-type connectors*. To make these connections easy, each connector comes color coded: red, black or white are the most common, but you may see red and blue or other combinations. Yellow is typically reserved for video connections. It doesn’t matter what color you connect to what connector as long as you are consistent and connect that color to the same side on the other end of the cable. If you do get your wires crossed, you won’t do any harm to your system and you really won’t degrade your system’s performance. You’ll simply mix-up the original intent of the mix: The soundstage produced by the mix engineer and producer is specifically thought-out to make the artist and music seem as real and life-like as possible. It may sound a bit picky, but for example, if the drummer is right-handed the mix engineer will generally pan the kit so that the hi-hats are in the right channel and the low toms are in the left channel. If you get your feed cables mixed up your right-handed drummer suddenly becomes a lefty.
* Some higher-end equipment uses special connectors for line-level interconnects such as XLR connectors; the same right/left conventions apply.
Wiring In and Out of Phase
However, wiring your speakers out of phase relative to each other will cause problems with the way your system sounds. When you hook your speakers up make sure the + on the amp output is wired to the + on the speaker terminal, and that the – on the amp output is wired to the – on the speaker terminal on both (all) speakers.
Most quality speaker cables are clearly marked + and – as a convenience (there is no such thing as a + or – piece of wire until it is energized by your amplifier). Typically, cable is marked with a + or –, or by color. Some speaker cable is designated using the name of the manufacturer on one conductor and no writing on the other; it doesn’t matter which one you designate as + or – as long as you are consistent. For simplicity sake, and to keep my hook-ups consistent, I always use the cable with the writing as my positive. Some cables have no marking at all but have conductors with differing colors, usually silver and copper. My convention is to use the copper as positive and silver as negative just because that’s the way I’ve done it for years. Other cable might have no marking at all but one conductor will have a line pressed into the insulator. Use this conductor as your – side (you can remember it as the line being one long minus sign.
If you are using cable that has no marking and the conductors are the same color, simply trace one conductor out with your hand and mark the corresponding ends with a piece of tape so you'll remember which conductor is meant for which terminal. If you have a meter with an Ohm function available, "ring out" the conductors and mark them accordingly.
It’s important to keep in mind that you won’t do any damage to either your amp or speakers if you wire out-of-phase, the system will just sound bad.
What To Listen For If Your Speakers Are Out Of Phase
There are two issues that come about from incorrectly phased speakers:
1) A significant loss in bass. Out-of-phase wiring affects all frequencies and diminishes total frequency response equally, but because bass frequencies have such long wavelengths and move so much air, those are the ones you’ll notice most. With a little detailed listening you can certainly tell if a mid-range or tweeter is out of phase, but it does take some practice. If you suspect you may have a phase issue, just switch the polarity (+/-) of one speaker which will change the phase relationship of both speakers. Sit back and listen to a track you are familiar with (and for best results just listened to before switching polarity). By doing this simple A/B (or +/-) test you'll be able to tell which polarity position gives you better bass response. (Be sure to turn your subwoofer off).
2) A more difficult-to-hear result of out-of-phase speakers is the loss of the stereo image. Basically, in-phase, your speakers will produce a seamless soundstage that appears between, above, and outside of, your speakers. With your speakers out-of-phase, you will hear two distinct and separate soundstages that appear to come from inside each speaker box independent of each other. The video below should help you hear what a phase issue sounds like.
The point of all of this is to give yourself the best possible listening experience so you can hear and feel everything your favorite artist wanted you to hear and feel. Happy listening!