hey guys i was looking into a system in my car, i have purchased an 8-inch elemental design subwoofer and i was wondering which kind of box i should get a ported one or sealed, the sound i am looking for is something that adds a little more bump while still sounding good for an occasional jazz track.

 

I've always been a fan of sealed boxes. For a particular speaker the recommended sealed enclosure size is usually smaller than a ported enclosure. Also, sealed enclosures are a lot more forgiving if they're a little too big or too small. Ported enclosures, on the other hand, are "tuned" to a certain frequency, and are basically acting as a big whistle. If you have the enclosure size or the port volume a little bit off, it can make a big difference in how the enclosure sounds.

Ported boxes are almost always louder than sealed boxes for the same amount of amplifier power, but only in a narrow frequency range near the tuning frequency. If you go much lower than the tuning frequency, the response drops off pretty quickly. In other words, a properly-designed ported enclosure will play *louder*, but a sealed enclosure will play *lower*.

Amplifiers are amazingly inexpensive these days, so I'd just go with a sealed box for the smaller enclosure and smoother frequency response, and just pick the appropriate-sized amp to get the volume you want.

 

cool, great info thanks man!

 

You're welcome - you can Google "sealed or ported enclosure" and find out a lot more information (although you have to wade through a lot of crap).

To do it right, a ported enclosure really needs to be designed for a specific speaker (both enclosure volume AND port volume). With a sealed enclosure, all you have to worry about is getting the internal volume right, plus or minus about ten percent.

Things were different 25 years ago. Back then, a 250-watt amp and a subwoofer capable of handling 250 watts were both expensive items, so it made sense to use a ported enclosure and take advantage of the higher efficiency. Nowadays, there are plenty of inexpensive subs on the market that can handle 500 watts or more, and a reliable 500-watt amplifier can be had for $250 or less, so it's easier to go with a less-efficient sealed enclosure and just throw more watts at it. Plus you get the benefit of more-accurate frequency response, and the ability to play lower notes without the the response falling off like a brick.

Sealed boxes also offer more protection for the speaker in high-volume applications, since the sealed mass of air will act as a "cushion" to help control the motion of the speaker cone. (This is why sealed enclosures are sometimes called "acoustic suspension" systems).

With a ported enclosure, if you're playing a note that's right at the tuning frequency for the box, the air in the box will provide almost no resistance to the movement of the speaker cone, so it's easier to "bottom out" the speaker cone when playing something loud. If you've ever had this happen, you can actually hear the various internal parts of the speaker hitting each other as they reach the limit of their travel.