Subwoofer phase normal or reverse

Subwoofer Phase Normal Or Reverse: The Ideal Phase for You

Subwoofers often sound better (or worse, who knows) when you turn the switch labeled ‘phase’ behind it.

It makes us wonder if all of the speakers in a room need to be in synced phases or not.

So the question for the day is which subwoofer phase normal or reverse?

Well, you’ll have to test and trial! Find out what’s working best for you. However, a subwoofer doesn’t need the reverse phase unless it’s wired out, out of phase, or inverted. Now, if you prefer sounds to travel a long distance, then the reverse phase is just for you.

This is enough to help you clear your confusion. But hold on, you can also find out other reasons for a subwoofer phase affecting your experience.

Spare a minute and read along!

Now, if you just want a quick comparison between the two phases you can jump into our final verdict section.

Let’s dive in-

Subwoofer Phase Explained

Time to answer the question- what does phase do on a subwoofer?

Well, the phase control of a subwoofer allows the speaker to delay incoming electrical signals by the conductors. Sometimes it helps the speaker integrate better with the other speakers in the room. But if the subwoofer is solo, the phase shift doesn’t make any audible difference. However, at high frequency, the sound effect is not as subtle. You can clearly hear the differences.

Here’s a graph explaining the audio frequencies of the normal and reverse phases of a subwoofer. The graph on top is the frequency of the subwoofer normal phase.

The one at the bottom is the frequency of the subwoofer reverse phase.

Here in the graphs, a speaker is tested with normal and reverse phases separately.

You can see that the difference between the frequencies of the normal and reverse phase is not much.

But at one point, the frequency in the normal phase decreases almost to zero.

And at that point, the frequency of the reverse phase is still high.

This means the wavelength of other speakers does not interrupt the wavelength of the subwoofer in the reverse phase.

But in the normal phase, the wavelength gets interrupted. This explains the noise cancellation effect.

Another fact, the polarity of the subs also changes if you switch the phases. That is mainly what causes the delay of the signal transmission.

Now, if you take a close look behind your subwoofer, you’ll notice a switch that is labeled ‘phase’ and control with degrees 0 and 180.

You can switch between these two phases using the controller. Usually, 0 degrees means a normal phase, and 180 degrees means the reverse phase of the subwoofer.

Some subwoofers have ‘variable’ phase control. These controls have more options along with 0 and 180 degrees.

That means you can set the subwoofer to any phase between 0 and 180 degrees. Just try it out and find your sweet spot for your best audio experience.

Choosing Subwoofer Phase: Normal or Reverse?

Understanding the reverse or normal phase of a subwoofer is very simple. However, before we come to a conclusion, let’s learn about the phases of a subwoofer. 

And also, how it affects the sound quality-

In order to find out the best phase setting for subwoofers, we need to take a deeper dive-

Normal Phase (0 Degree)

When you buy a brand-new subwoofer, the phase will be usually set to normal. When the subs are in a normal phase, it’s called in-phase.

That means the incoming signal is synced with that of the other speakers around the room.

Now, you might want to know what happens when they sync-


The opposite movement causes a certain amount of noise reduction or cancellation.

Here’s a graph showing the frequency response of a subwoofer and the frequency of other speakers-

This graph depicts the frequencies of speakers in two different scenarios.

The first scenario [with the red line] is the frequency of all the speakers in a system with a normal phase.

The second scenario [with the blue line] is the frequency response of a single main speaker.

Now, does subwoofer phase make a difference?

Of course, it does. When the frequency is low, the difference between the response of speakers with normal phase and main speaker is maximum. This means the sound is clearer but has greater chances of distortion in the normal phase. But in the reverse phase, it’s the exact opposite. The sound is louder than ever.

Why Would You Prefer the Normal Phase?

If you’re playing the subwoofer in the normal phase, there’s no delay in transmitting incoming signals from the main channel.

This will make your listening experience smooth and uninterrupted. 

Which is great news, right? 

And as for noise cancellation, your home theatre experience will not be unsatisfactory. But your listening experience may not be complete.

You’ll find a lot of choices for you out there. So, here’s a list of speaker systems that will make your listening experience complete-

Why Won’t Normal Phase Work for You?

If your speakers are placed at non-uniform distances around the room, the normal phase will affect your listening experiences. 

You might hear sound dropping at certain points.

That’s because the other speakers (especially satellite speakers) generating the same wavelength interrupt the wavelength of subwoofers.

For this reason, you’ll hear distorted sounds from the speaker.

You can also add a subwoofer isolation system to make your listening experience better.

In this case, changing the placement of the speakers might decrease the noise cancellation effect.

However, switching the subwoofer phase setup to the reverse phase might save you the hassle.

Reverse Phase

If your subwoofer’s phase is set to 180 degrees, it’s in the reverse phase.

In this reverse subwoofer phase, the conductors, that transmit signals from the main channel, switch polarity. For this reason, the signal transmission gets delayed. 

As a result, the beat of the cone reverses and the sync becomes out of phase with the other speakers. The air beats through the back of the subwoofer driver as well.

Are you wondering what happens when the subwoofers are out of phase?

It’s simply the reverse function of the normal subwoofer phase. The subwoofer cone will move in when the cone of the other speakers in your room move out. And vice versa. This function reduces a lot of the noise cancellation effects. Resulting in a clearer and louder sound production.

Why Would You Prefer the Reverse Phase?

If you have a big room and you want your music to have the perfect bass, then the reverse phase is perfect for you.

If you’re planning for a setup, with rear backs or front heights, you can also consider using the reverse phase. 

Though reverse-phase also requires an evenly spaced-out sound system setup. Which is similar to the normal phase.

Make sure all the speakers have equal distances between them in a room. The speakers also need to be facing each other. Otherwise, there is a chance of distortion.

The wavelength of the subwoofers in a reverse phase complements that of the other speakers in a room.

This causes zero interruptions and decreases the noise cancellation effect. And because of this, the sound generated from the subwoofer is louder and clearer. 

This is why speakers in reverse phases integrate better with all other speakers in a setup.

Why Won’t Reverse Phase Work for You?

The reverse phase is not only about loud and clear music. Reverse phases can harm your speakers in several ways.

The delay in transmission often distorts a subwoofer, especially the big ones.

So, between 15 inch and 18 inch subwoofers, 18 inch subwoofers have greater chances of distortion.

There are some other ways the reverse phase can put your speakers in trouble.

Sometimes the dust in the port of the speaker can cause difficulties in the reverse piston movement. This is the reason why cleaning a speaker is important.

Not only does the speaker need cleaning, cleaning the cabinet is equally important.

It doesn’t matter if your speaker is covered by some of the ideal woods for speaker cabinets, make sure it doesn’t trap dust.

Also, there’s a possibility the port of your speaker is ill-designed. Thus, producing louder sounds when playing in the reverse phase.

The delay of the signal is often audible, especially in between a frequency range of 20hz-100hz.

Below 20 HzSubtle
Between 20-100 HzAudible
Above 100 HzSubtle

Here’s a graph showing the frequency of subwoofers vs the frequency of other speakers-

Here in the graph above, the frequencies of speakers in two different scenarios are shown.

The first scenario [purple line] is the frequency of all the speakers in a system with a reverse phase.

The second scenario [blue line] is the frequency response of a single main speaker. 

The graph means that the sound quality of speakers in the reverse phase becomes loud and edgier. At low frequency, there was a huge difference in the response.

But the sound intensity of the speakers with reverse phases increased. This allows the sound to be loud and clear.

Now to find our perfect audio setting, we’ve got to test and trial both of the phases. 

After the subwoofer phase test, you can set the switch to a mid-level or upper-level bass. Which is somewhere beyond a frequency range of 100 Hz.

Keep in Mind –

  • If you have more than one speaker, don’t switch phases one by one.
  • Make sure both subwoofers in a surround system are in the same phase when playing.
  • Cleaning the subwoofers once a month will save your surround system.

Final Verdict

Your decisions regarding the normal and reverse phase come down to some factors. These are- 

  • the orientation of the speaker setup, 
  • the room size, 
  • the quantity of the speaker, 
  • and lastly your personal experience.

Here’s a table that summarises the differences between the phases:

Now, ask yourself which car subwoofer phase 0 or 180?

The best way to choose a subwoofer phase would be to try out both of the phases. This way you’ll be able to find out which one works the best for you.


What phase should a subwoofer be set to?

There’s no right answer here. If the normal phase doesn’t work for you, it can be changed to the reverse phase easily by flicking the switch. 

Do inverted subwoofers sound better?

In most cases, yes, the sounds of the reverse phase subwoofers are clearer and louder. And the bass is heavier than that of the normal phase. This occurs because the wavelengths produced by the reverse phase don’t interfere with the wavelengths of the other speakers.

How do I know if my subwoofer is out of phase?

For this, you’ll need to do a simple step. Observe the cone of the subwoofers, if the cone moves in when the cones of other speakers move out, it’s in the reverse phase. This is also known as the out of phase. 


Let us conclude by saying that your listening experience is totally up to you. Make sure to keep your subwoofers clean and dust-free for a better sound experience.

Do comment below and let us know which subwoofer phase normal or reverse, you are going for.

Until then, roll with the rhythm!

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