# What's the difference between a ported subwoofer vs a sealed subwoofer?



## vincedea

What is the difference between the 2? I'm trying to see what type of subwoofer I should pair with my nht SZ 2.0 speakers.

I use the speakers with my computer.


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## duncan1

Your question is so general it  sounds like a leading question.Thick books have been written on loudspeaker cabinet design and loudspeaker design that it is easy to "shoot someone down in flames"
              So I will limit the reply to a VERY simple answer---if anybody wants to elaborate then let them.
                   Reflex/ ported  loudspeakers generally go down to a lower resonate frequency  and are more efficient.
                      Sealed boxes although not achieving  the same depth of bass- have a more controlled bass that some find preferable-sounds more -punchy/solid etc.So a reflex /open ported loudspeaker must be built to a higher spec.to achieve similar reproduction.--- can you see how this question can be a "can of worms" 
             A MILLION things can change things-internal construction/type of loudspeaker and so on .
                      This is a science in itself - So I must state what I said is is a SIMPLE answer to a SIMPLE question.
                           Opening up my speaker design manual there are reams of maths which you don't want to hear.


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## Kaseywills

Sealed is most commonly used subwoofer boxes, best thing where space is an issue and it produce tight, accurate bass with flat frequency response curve. Whereas ported subwoofer are larger in size and produce louder bass than sealed enclosures.
   
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## 3X0

Ported subwoofers in the same class will generally also have greater extension than sealed subwoofers, especially response around and below 20Hz.


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## Lorspeaker

I had a Rel sub once...v musical. Think it's sealed.


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## cel4145

3x0 said:


> Ported subwoofers in the same class will generally also have greater extension than sealed subwoofers, especially response around and below 20Hz.




That's not accurate. 

If you take a good sub driver and built a sealed and ported sub with it, a well-designed ported implementation should have fairly linear output down to its tuning point, and then drop off very fast. A sealed sub version will typically drop off with a much more gradual slope, extending deeper, although with less overall volume output than the ported sub version will have down to its tuning point. 

Here is the Rythmik F15 sealed sub:



And their FV15 ported sub which I believe uses the same driver and the same amp.



The FV15's output has dropped to nothing by 10hz. The F15 digs a little deeper. But the FV15 has more SPL down to it's tuning point than the F12.


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## 3X0

Quote: 





cel4145 said:


> That's not accurate.
> 
> If you take a good sub driver and built a sealed and ported sub with it, a well-designed ported implementation should have fairly linear output down to its tuning point, and then drop off very fast. A sealed sub version will typically drop off with a much more gradual slope, extending deeper, although with less overall volume output than the ported sub version will have down to its tuning point.
> 
> ...


 

 Sorry, you're right in that regard. I was referring to the usual market of ported subwoofers having significantly larger enclosures in the same price range as sealed subwoofers, with a tuning frequency that is quite often below 20Hz (i.e. 16-18Hz), producing significantly higher output to that frequency -- I was conflating extension with SPL.
   
  To get the same output sub-20Hz in a sealed enclosure, you'd usually have to go with multiple subwoofers/drivers. Ported makes it easier and cheaper to hit SPL goals at a desired sub-bass frequency.
   
  In other words, although sealed implementations are going to have more extension past the resonant frequency of the ported competition, they're not going to feel more extended due to the lack of output by that point.
   
  I'd also argue that any response below ~16Hz doesn't count, once you consider empirical DBT of sealed and ported implementations that reach 16Hz with linear response.


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## cel4145

3x0 said:


> To get the same output sub-20Hz in a sealed enclosure, you'd usually have to go with multiple subwoofers/drivers. *Sealed* makes it easier and cheaper to hit SPL goals at a desired sub-bass frequency.
> 
> In other words, although sealed implementations are going to have more extension past the resonant frequency of the ported competition, they're not going to feel more extended due to the lack of output by that point.




I'm guessing you meant "ported" in that 2nd sentence. Yep. I run dual 18" sealed subs in my HT setup. 

The other thing that can happen, too, is that people coming from budget ported subs to larger sealed subs will feel less presence down low because of the reduced distortion, since budget ported subs tend to have a lot of distortion at and below the tuning point.


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## 3X0

Quote: 





cel4145 said:


> I'm guessing you meant "ported" in that 2nd sentence. Yep. I run dual 18" sealed subs in my HT setup.
> 
> 
> 
> ...


 

 Oops, yeah.
   
  I know my 12" doesn't have much usable response in that sub-sub-bass due to insufficient SPL, while ported subwoofers in the same price range of ~$700-800 hit harder a little lower while being more distorted. Of course mine is only a little larger than one square foot and the ported designs at the price are pretty huge.


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## cel4145

3x0 said:


> Oops, yeah.
> 
> I know my 12" doesn't have much usable response in that sub-sub-bass due to insufficient SPL, while ported subwoofers in the same price range of ~$700-800 hit harder a little lower while being more distorted. Of course mine is only a little larger than one square foot and the ported designs at the price are pretty huge.




I went from an Outlaw Audio LFM-1 EX ported sub, which is big, to two Chase Home Theater 18" sealed subs, which are even bigger. 


(the Outlaw is in the middle)

At 16hz to 20hz, the EX would keep up with one of the CHTs, but the CHTs have a tighter response and of course much more output from 30hz on up.


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## cricketmanboy

I think ported is the same as sealed except that there is a hole in the box. Inspecting the hole I found that it is in fact a tube of some sort. I put my hand inside the tube (approximately 10") and I was bitten. My co-worker (let's call him Sam) told me that he had lost his cat, Mrs. Leslie Peatmoss. I remember being bitten this cat at (let's call him Sam's) Christmas party. I had been drinking and popping handfuls of Percocets and was inappropriately touching the cat. The bit marks were very nasty and thank God (he is my personal Savior) I had consumed way too many pain pills. The pills and booze gave me the courage to ask Helen to go to the Nickleback concert. That whole evening was a waste of time - sucky music and she's worse than me with the pills. peace out.


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