What happens when a speaker is wired backwards? Will it damage the speaker?
speaker polarity will be determined by the connection between the amplifier and
the speaker. Connecting the positive amplifier terminal to the positive
speaker terminal and the negative amplifier terminal to the negative
speaker terminal will ensure that you have correct polarity. If that wiring is
reversed - negative to positive, positive to negative - well then your speaker will
be in inverse polarity. But what is polarity anyway? A sound wave is a series
of positive and negative pressure changes in the air and an audio signal
in a wire is a series of positive and negative voltages. You can see on this
graph that the center line represents normal air pressure (or no voltage). As the
waveform goes above the center line, there's a positive change in voltage or
air pressure. And as the waveform goes below the center line, there's a negative
change. If the polarity of this wave were inverted, the positive periods would
become negative and the negative periods would become positive. These two images
show the same exact audio wave - one with correct polarity and one with polarity
inverted. How does polarity relate to a speaker? A speaker pushes and pulls air
in an alternating rhythm to create audio waves. In this model, the default position
for the speaker is zero. When you apply positive voltage, the speaker pushes
outward. When you apply a negative voltage, the speaker pulls inward. As a
speaker pushes outward and pulls inward, it creates a series of positive and
negative pressure changes, which causes a ripple effect from the speaker all the
way to our ears. So if you reverse the wiring
between the amplifier and the speaker - connecting negative to positive instead
of negative to negative - the speaker will push when it's supposed to pull and it
will pull when it's supposed to push. Well how does this effect sound quality?
While I always recommend wiring speakers correctly, the truth is that it matters
more in some situations than it does in others. For example, if you only have one
speaker you probably won't notice at all an inversion in polarity. Listen to
these two audio clips. This first one is in the correct polarity the second one
has inverted polarity. You probably didn't notice much of a difference.
That's because audio waves are an alternation between positive and
negative and when you flip those around, the sequence of positive and negative is
still present, and so the audio wave is still created. Now what if you have more
than one speaker? Well it sort of depends. If all of your speakers are wired the
same way you still won't notice the difference.
But let's say you have one speaker wired with correct polarity and another
speaker wired with reversed or inverted polarity. To hear this example, it's best
to wear headphones. I'm going to give you the correct polarity on the left side
and inverted polarity on the right side you'll definitely notice the difference
here. In addition to that very distracting effect caused by a left
speaker and a right speaker with different polarity, you can also have
issues in any multi-speaker situation, be it a line array at a live sound concert
or distributed audio throughout a building, and this is why. When you mix
two waves with the same polarity, they'll add together. But if you mix waves with
inverted polarity, they'll cancel each other out. So if you have nine ceiling
speakers and the tenth speaker is wired with inverted
polarity, Instead of working with the first nine speakers, it's going to work
against them. This can be used to our advantage such as in subwoofer arrays,
but it's more noticeable in certain situations than others. If you got value
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AudioUniversityOnline.com. Let me know if there are any concepts that you'd
like me to go over in future videos in the comments. Thanks for watching.