The main difference between ported and sealed subwoofers is the type of enclosure they use.
How speaker enclosures influence sound
Loudspeaker enclosures influence a loudspeaker’s sound in the following ways:
- Prevent front-firing sound waves from interfering with rear-firing waves
- Enhance the sound produced by bass drivers
- Absorb the vibrations from the drivers
- Direct the dispersion of the sound
Ported Subwoofers
Ported subwoofers use a vented enclosure, which has a hole or port that allows air to move in and out of the enclosure. This can help to increase the volume of the subwoofer and extend the bass response, but it can also add some distortion to the sound.
Unlike sealed enclosures, ported (also known as “vented” or “bass reflex” enclosures) include at least one tube-like opening or vent connecting the interior of the enclosure to the outside. These enclosures not only enable a deep bass frequency, but enhance it through the vent or tube. This works in the same way as blowing through the opening of a Coke bottle and as with a bottle, the size of the bottle and contents will affect the sound. It is therefore very important that the vent or port on a bass reflex speaker be precisely tuned to the natural low end of the driver.
The basic pros and cons of ported subwoofers
- Pros: Higher volumes, stronger bass, and compact enclosure size, greater efficiency than with sealed enclosures
- Cons: More difficult to achieve a clean and accurate frequency response, less precise and “boomier” bass (which some may actually see as an advantage), bass reflex vents or tubes that are not properly designed can lead to “wind noise”
Sealed Subwoofers.
Sealed subwoofers use a sealed enclosure, which does not have any holes or ports. As the name indicates, this type of enclosure is a completely sealed, airtight box around the back of the driver that prevents sound waves from the back of the driver from interfering with those from the front.
One problem with this design, however is that the enclosure itself can create unwanted resonances that color the sound. These resonances, however, can be kept in check by the use of low-resonance materials (such as aluminium and wood) for the enclosure as well as insulating materials such as sheep’s wool inside the enclosure.
This can result in a more accurate and controlled sound, but it may not be able to produce as much volume or bass as a ported subwoofer.
The basic pros and cons of sealed subwoofers
- Pros: Simple, space-saving construction, precise playback of even the deepest frequencies, good power handling, excellent transient response, no wind noise (as with ported enclosures)
- Cons: Require more power to overcome the internal air pressure = less efficient.
The position of the port in a ported subwoofer can affect the sound quality and performance of the subwoofer. The location of the port can influence the frequency response of the subwoofer and may affect the overall balance of the bass output.
In general, it is important to position the port in a way that allows it to function properly and helps to optimize the sound quality of the subwoofer. This may involve positioning the port in a specific location on the enclosure or using a specific type of port design.
So which subwoofer is the right for you?
Both speakers can deliver excellent sound. However, each subwoofer type has its preferred use cases and for certain purposes. If you’re looking for a high-end stereo speaker for listening to classical music and jazz, a sealed subwoofer might be the right choice. Many high-end subwoofers even contain wave guides for the better dispersion of the treble range. Ported speakers are best for movies and TV shows that feature low end bass below 20 Hz.
Overall, the position of the port in a subwoofer can be an important consideration and can affect the sound quality and performance of the subwoofer. It is important to consider the position of the port when selecting and setting up a subwoofer to ensure that it is able to perform to its full potential.
Overall, the choice between a ported or sealed subwoofer will depend on your specific needs and preferences. Ported subwoofers may be a good choice for those who want more volume and bass, while sealed subwoofers may be a better choice for those who want a more accurate and controlled sound.
