Speakers are excellent entertainment accessories. A pair of good speakers spices up your entertainment experience. Correct installation and connection are essential to make the most of their power and potentials. In this write-up, we will discuss a critical parameter – POLARITY OF SPEAKERS – while restricting our focus to how it matters.
- Does connecting speakers backwards affect their performance?
- Does reversing wires damage the speakers?
- How much important is speaker polarity?
- What are the ways to check speakers’ polarity for the right connection?
Polarity determination is done while setting up the wire connection between the speaker and the amplifier. The correct polarity refers to a situation when the positive amplifier terminal and negative amplifier terminal are connected to the positive speaker terminal and negative speaker terminal, respectively. Any mismatch implies inverted or reverses polarity.
Audio Wave Polarity
A sound wave travels through a series of positive and negative changes in air pressure. In a graphical presentation, a positive difference in air pressure is shown through a line above the Normal Line that represents normalcy in room air pressure. If the line is below the Center Line, it shows the negative change in pressure.
In the case of reversed wave polarity, positive periods and negative periods will change to negative and positive periods, respectively. It depicts the scenario of the same wave with inverted polarity.
Let’s elaborate on the topic. Imagine a scenario of a drum creating a sound wave. When you strike the drum with a drumstick, the drumhead, i.e. the upper membrane starts to oscillate up and down and thus, creates positive and negative changes in surrounding air pressure.
Now the question is which direction the drum head moves first. The drumstick hits the drum from the upward to a downward trend. The drum head, thus forcibly moved downwards, causes air pressure to dip in the negative direction.
A mix of two identical signals having the same polarity results into signals summation. On the other hand, mixing of two identical signals having reverse polarity causes the messages to be cancelled out. Placing a microphone above the drum will cause the preliminary part of the wave to be negative, but the same will be positive if the polarity of the microphone wires is reversed.
What If a Speaker’s Polarity is Reversed?
When the wires from the amplifier to the speakers are swapped, it is called inverted or reversed polarity. It will cause the speaker to move inwards when it should have moved outward and vice versa. The speaker will create the sound wave precisely opposite to the microphone-recorded signal.
Does Speaker Polarity Negatively Affect Sound Quality?
Correct wiring is always recommended, but incorrect installation has varying effects subject to the situations. In some cases, improper wire connection is hardly noticed, whereas, in other conditions, it might cause significant issues.
Inverted Polarity with One Speaker
In the case of only one speaker, the effects of inverted polarity are barely noticeable. Sound waves create an alternative fluctuation in air pressure and audio signals passing through a wire are alternative electrical currents.
It implies an equal, but opposite negative change will virtually offset every positive change. This explains the absence of any audible difference between an audio wave in polarity and that out of polarity.
Inverted Polarity with Multiple Speakers
In such cases, the effects are noticeable. If both of them are wired identical – in the right or reversed polarity –it will virtually produce no results. But if there is a mismatch in-home or car speaker polarity, it will cause a massive impact. To feel the problem, you need to use headphones or attach the speakers with stereo.
What If You Are Using an Array of Speakers?
In such cases, reversed polarity in one of them will cause considerable changes in the behavioural pattern of the array. Line arrays of full-range speakers – they are used in live sound reinforcement – should be wired identically.
The speakers in subwoofer arrays – such arrangements sometimes have speakers with reversed polarity to achieve improved directionality – are usually wired in right polarity.
If polarity needs a change, it’s done in an amplifier DSP or an audio console and not in the wiring at the positive or negative speaker terminals. If polarity inversion is not allowed in your amplifier DSP or audio mixer, using a polarity inversion adapter will address the issue.
Does Inverted Polarity Damage Speakers?
Reversed polarity causes significant and various changes in sound quality but fortunately causes no damage to speakers. However, it would help if you stuck to correct wiring for the tremendous acoustic experience.
How to Test Wire Polarity
As long as the speakers are wired the identical way, the effects of reversed polarity will go unnoticed. However, correct wiring is always recommended for every single speaker while connecting it to an amplifier.
How to determine speakers positive and negative terminal? That’s a crucial question. If your wire has a label on it – for example, red and black colour or plus and minus symbol – it will be easy to test polarity. You need to match the colour or logo of the terminal while connecting the amplifier to the speaker.
What if your wire comes with no label? In that case, you can test speaker polarity in either of two ways:
Specific tools are specially designed to deal with situations like these. The SPEAKER TASTER is one such tool to help you test speaker polarity. It also comes with a signal generator. Yes, it’s a small but significant investment as you will always have the tool at your disposal to test speakers quickly without an amplifier.
- Get a 9V battery.
- Check which terminal is positive and which one is negative. Attach one speaker wire to the positive terminal and another speaker to the negative terminal of the battery.
- Watch which way each of them moves while making a connection.
Depending on the way a speaker is connected to the amplifier or wired internally, it will move inward or outward to respond to a given input signal. If only one speaker is involved in the scenario, the direction will produce a nil effect on the perceived sound. This is because our ears are not sensitive to the absolute phase. If more than one speaker is used, their interaction is defined by polarity. In such cases, contradiction is an important parameter to consider.