Diagnosing Speaker Phase Problems

By Jack Sharkey, September 14, 2016.

One of the biggest causes of poor performance in an audio system is also one of the easiest to fix – if you know what to look for. Connection issues usually come in two forms: mixing up the Left and Right channels and wiring your speakers out-of-phase. Here's a quick guide on how to properly connect your stereo speakers and what to listen for if you suspect there may be an issue.


Wiring the Left and Right

If you have a component system with a separate streaming device, DVD or CD player, or turntable, you’ll be connecting those to your amp or pre-amp typically via RCA-type connectors.* To make these connections easy, each connector comes with a color code: red for right and either black or white for left. 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 so to speak, you won’t do any harm to your system and you really won’t degrade your system’s performance. You’ll simply get the original intent of the mix engineer and producer mixed up: The soundstage produced by the mix engineer and producer is thought-out pretty specifically to make the artist and music seem as real and life-like as possible. It may sound a bit picky to some, but 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 use special connectors for line-level interconnects such as XLR connectors, the same right/left conventions apply.


Wiring In and Out of Phase

What will cause problems with the way your system sounds is wiring your speakers out of phase relative to each other. 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 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.


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.


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. Simply put, out-of-phase wiring affects all frequencies equally 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 first. 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, you can easily 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, 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 it 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!


KEF System Wiring Diagram


  • Frank
    Can you use kef q100 as rear for surround sound?
  • KEF

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