When investigating speaker purchase and setup, you might have come across the term phase control. For those not experienced in speaker installation or setup, it might be confusing. We explain what is meant with phase control and the term – subwoofer phase 0 or 180.
Phase control in a subwoofer
Phase control or phase setting, as it applies to a subwoofer, refers to the signal delay. It is an electrical instruction and operates from 0 to 180 degrees. When set correctly it allows the subwoofer to integrate and operate better with the rest of the speakers in the system.
Much depends on the space that you are using the speaker in. What this setting does is reverse the subwoofer’s polarity. If, for example, your subwoofer is positioned on the other side of the room to the main speakers, reversing the polarity will improve audio output. If drivers on the subwoofer move in while the main speakers move out there will be a loss of volume, bass, and quality. They need to be in phase.
What is the best subwoofer setting?
This is one of the last settings to adjust after you have the crossover settings correct as well as the volume control (gain) set correctly.
Many people are intimidated by the idea of setting the correct phase for your subwoofers. One can always employ a professional to set the system up. You can even do this for systems purchased online.
If you want to do it yourself, it is actually quite simple and nothing to be afraid of. It does, however, need to be done correctly to get the best performance from your system.
Some have a very simple switch, a digital button that will change the phase from 0 to 180. All you then need to do then is to decide is it better and louder at one setting or the other. This is a quick and easy exercise and does not require an expert ear.
With incorrect phasing, the subwoofers will cancel the low-range (bass) frequencies from the main speakers. You want them to work together and compliment each other. This creates balance and harmony.
Getting it perfect
As we have explained, it is a lot less complicated than it appears for many. To get it perfect, however, might require some trial and error. This difference is not always dramatic.
The best way to do this is to gradually turn the subwoofer volume down and keep note of the exact volume level. With full volume on the subwoofer, you will not be able to discern the difference. You also do not want it too low so that the main speakers drown out the subs. It is all about balance and experimentation.
With some speakers and subwoofers, correct positioning is as important as getting the phase control right. The best sound is the one that sounds right for you so take the time to try different options. Even small changes can make a huge difference to your listening pleasure. Ensure that you keep a record as you go so that you can remember when and where you hit that desired sweet spot.
Some changes might require a change in crossover settings so keep this in mind.
Is adjustable phase control necessary?
Some people insist that a simple 0/180 subwoofer phase control is not enough and that it needs to be a ratio scale phase control. This is a debatable issue. With most systems, setups, and room environments, it is generally not necessary.
For a true music aficionado, or if you have a complex system and floor layout, it might help to some degree.
This is something best left to the experts. If you are intent on advanced phase control be prepared to do some research and spend the time to get it perfect. There is audio software that can assist.
Keep it simple
For the average home user, getting the phase control right is fairly simple. To get your subwoofers in phase with the other speakers, simply experiment. Turn the sub volume up relatively high. Play some bass-heavy music and listen carefully from your regular position in the room. Have someone flip the switch from 0 to 180 and listen for any noticeable bass improvement.
If you do not determine a marked difference, leave it at 0.
The best sound is the sound that sounds good to you. It should cover the full range of frequencies and deliver a deep rich sound that is clear and without distortion. While there is software available for audiophile experts, quality sound is somewhat subjective.
Follow the basics of system setup and speaker position and by all means, experiment with the subwoofer phase to enjoy the best sound for your system.
This article was last updated on September 8, 2021 .