How Do You Know Positive and Negative on Speaker Wire
What happens if speakers are connected backwards? Can reversing speaker wires damage a speaker? Does speaker polarity matter and how practise you test for right speaker polarity? In this post, you'll notice out.
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While it is recommended to always wire speakers correctly, the effects of incorrect wiring vary depending on the situation. In some situations, a miswiring will barely be noticed, and in other situations it might crusade severe problems.
What is Speaker Polarity?
Speaker polarity is determined when connecting the wires between the amplifier and the speaker. When the positive amplifier terminal is continued to the positive speaker final and the negative amplifier final is connected to the negative speaker last, the speaker volition exist in correct polarity. When these connections are swapped, the speaker will be in reverse polarity.
Polarity of an Audio Wave
A sound wave is a serial of positive and negative pressure changes. Await at this sound wave on a graph. The centre line represents normal air pressure in the room. As the line goes above the center line, at that place is a positive change in air pressure level. As the line goes below the heart line, there is a negative change in air pressure.
If the polarity of this wave is reversed, the positive periods will become negative and the negative periods will become positive. This is what the same wave would expect like with polarity inverted:
Imagine the sound wave created by a drum. When the drum is struck by a drumstick, the upper membrane, or drumhead, begins to motility down and up, creating negative and positive changes in air force per unit area around it.
Which direction does the drum head movement first? The stick strikes the pulsate head from the meridian and forces it downwards. This downward move of the drum head creates a negative change in pressure.
If you lot place a microphone above the drum, the first part of the wave will be negative.
If you were to reverse the polarity of the wires in the microphone, the first part of the wave would be positive.
Constructive & Destructive Interference
If 2 identical signals with the same polarity are mixed together, the signals sum. The positive stage of both waves are aligned and the negative phase of both waves are aligned. The result is a bespeak that is twice the amplitude of each individual bespeak. This is chosen constructive interference.
Anytime two identical signals are mixed together with inverse polarity, the signals cancel out. In this instance, one wave is positive while the other is negative, and vice versa. The result is silence. This is called destructive interference.
There is a big difference betwixt polarity and phase! I wrote this article about information technology that will help you to see why information technology'south really important to understand the difference.
How a Speaker Works
A speaker and a microphone operate on the aforementioned basic principles. In a microphone, electricity is created when audio causes the diaphragm to move. In a speaker, move is created when electricity passes through the wires.
You can learn more by reading this article I wrote nigh how microphones work. Become to the 'Dynamic Microphones' section of that article to see a more detailed description of this concept.
When no electricity is being sent through the speaker wires, the speaker rests in its default position. When an alternate electric current, such equally an audio point, is sent to the speaker, information technology starts to push button outward and pull in. Y'all can run into this in the post-obit epitome.
Every bit a speaker vibrates forward and astern, it displaces the air particles in the atmosphere, forming negative and positive changes in force per unit area. This causes a concatenation reaction through the air from the speaker to our ears.
If this concept doesn't brand sense, yous'll desire to cheque out this article that explains how sound travels through space. Understanding how sound waves can interact volition help yous empathise why speaker polarity is so important!
What Happens When a Speaker'southward Polarity is Inverted?
When the wires from the amplifier to the speaker are crossed, the speaker polarity volition be inverted. This means that the speaker volition move inward when it is supposed to move outward, and outward when information technology is supposed to motion inward.
The sound wave created past the speakers volition exist the exact opposite of the point recorded by the microphone. How will this modify the sound?
Can Speaker Polarity Affect Audio Quality?
While it is recommended to always wire speakers correctly, the effects of incorrect wiring vary depending on the state of affairs. In some situations, a miswiring will barely be noticed, and in other situations it might crusade severe bug.
Reversed Polarity with Ane Speaker
If only one speaker is existence used, the effects of reversed polarity will non be noticeable.
Listen and compare these two audio clips. The first one is in the correct polarity, while the second is in reversed polarity.
Yous will not detect the difference between these clips, because the frequencies contained in them are identical. Although the positive and negative pressure changes accept been inverted, it's non possible to hear the difference.
Audio waves are alternating pressure fluctuations and audio signals in a wire are alternating electric currents. This ways that virtually every positive change will exist met with a almost equal but opposite negative modify. For this reason, at that place is virtually no audible divergence betwixt an audio signal in polarity and out of polarity.
Reversed Polarity with Multiple Speakers
Reversing polarity with multiple speakers can cause more noticeable effects. If both speakers are wired the aforementioned, whether in the correct polarity or reversed polarity, in that location will be most no effect. However, what if one speaker is wired in the right polarity and the other is reversed? This volition crusade a significant result.
To hear this, it's best to yous utilise 2 speakers in stereo or to use headphones. In the video at the height of this page, there are audio demonstrations of this scenario.
If you lot are using an array of speakers, inverted polarity in one of them will crusade significant changes in how the array behaves. Line arrays of full-range speakers, such as those used in live sound reinforcement should all exist wired the same way.
Fifty-fifty the speakers in subwoofer arrays, which sometimes contain speakers with inverted polarity to achieve better directionality, are usually wired with correct polarity. Any changes in polarity are near ever made in an audio console or amplifier DSP, rather than in the wiring of speaker terminals. If your audio mixer or amplifier DSP does not permit for polarity inversion, you tin use a polarity inversion adapter.
Can Wrong Speaker Polarity Damage Speakers?
Inverted polarity tin cause a variety of changes to sound quality, simply is it likewise dangerous for your amplifier and speakers? The answer is no, thankfully.
The voltages beingness applied to a speaker with inverted polarity are no different from those supplied to a speaker with correct polarity. Your equipment volition not exist damaged. The worst matter that volition happen is that it will not work well acoustically with properly wired speakers. For this reason, it's best to stick to the standard, and ensure right wiring.
How to Test Speaker Wire Polarity
Fifty-fifty though the effects of inverted polarity are not noticeable so long every bit all speakers are wired the aforementioned mode, information technology is a best exercise to wire each speaker correctly when connecting to an amplifier.
With Speaker Wire Labels
If you have labels on your wire, such equally plus and minus symbols or red and black colors, it is very piece of cake. Connect the cerise (or +) terminal on the amplifier to the ruddy (or +) concluding on the speaker. Connect the blackness (or -) terminal on the amplifier to the black (or -) final on the speaker.
Without Speaker Wire Labels
Maybe you have already run cable through walls or conduit only to notice that the wires are non labeled. Or perhaps yous are installing machine speakers and want to verify you're wiring the speakers correctly from the harness.
Here are ii methods that I recommend for testing speaker polarity.
Examination Speaker Polarity with a Speaker Tester
In that location are tools made specifically for situations like these.
This speaker tester is relatively inexpensive and will not only allow you to examination speaker polarity, but it also has a signal generator.
It is a small investment that you will use all the time.Information technology'southward nice to have a tool that allows you to quickly test speakers without an amplifier. Watch this video to come across it in action.
For a more than professional person choice to use with NL4 and NL8 speakON connectors, check out this speaker tester. This one is more suited for those working in live sound reinforcement.
Test Speaker Polarity with a Smartphone
If your system is already wired and you are able to pass an audio betoken from input to output, you can test speaker polarity using a smartphone app.
I recommend the Studio Six Speaker Pop App. Information technology works past connecting the audio output of your smartphone to the input of your system. Then place the microphone of your smartphone in front end of the speaker you want to test. The app will send a positive impulse out to the organisation and measure the polarity of the sound coming out of the speakers.
Test Speaker Polarity with a 9V Battery
If you're looking for a quick, free way to examination speaker polarity, you can practise it using the following method:
For this technique, you lot volition demand a 9V battery.
- Place one speaker wire to the positive (+) final of the bombardment.
- Place the other speaker wire to the negative (-) terminal of the battery.
- Notice which way the speaker moves every bit y'all make this connection.
- If the speaker moves outward, and then the speaker wire connected to the positive (+) last of the battery is the positive (+) wire.
- If the speaker moves inwards, and so the speaker wire connected to the negative (-) terminal of the battery is the positive (+) wire.
This video clip shows what yous are looking for when yous apply the battery to the speaker wires:
Source: https://audiouniversityonline.com/speaker-polarity/
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