Ported vs. sealed....whats the pros and cons?

 

Bronze Member
Username: Kunit

Post Number: 12
Registered: May-05
I'm going to eventually build a box. I like the ones built with a space for the amp. I'm going to have a 12 inch, 10 inch and 8 inch pumpin. I just want to know what is the difference between ported and sealed. Ported seems like a lot more trouble...I have no idea about tuing to hertz and stuff..If you could fill me in on the difference between the boxes please do!
 

Silver Member
Username: Addicted2bass

Miami, FLORIDA USA

Post Number: 707
Registered: Nov-04
wait are you going to have an 8,10, and 12 inch sub goign all at the same time?
 

Silver Member
Username: Addicted2bass

Miami, FLORIDA USA

Post Number: 708
Registered: Nov-04
Ohyea and for your question the differnce between ported and sealed is. Ported usaly shows a 3db increase over the sealed around the tuning frequency of the ported enclosure.For sq you will pretty much have to decide but most say sealed enclousres sound better than ported...but im the opposite..I like the sound of ported over sealed
 

Silver Member
Username: Dankman

South Bend, Indiana United States

Post Number: 165
Registered: Jan-05
Word up, ported = loud
 

Bronze Member
Username: Kunit

Post Number: 13
Registered: May-05
yea..im going to run an 8, 10, and 12.
 

Silver Member
Username: Jeremyc

Germany

Post Number: 676
Registered: Jun-04
an 8 a 10 and a 12, Hmmmmm can we say cancelation???????
 

allende5
Unregistered guest
I preferred ported as well. I think the bass is much deeper. Use WinISD to help configure your box. You need the Thiele Small parameters for your sub. Based on the amount of space you have, and want to tune it to, you can "give" and "take", if you will, the size of enclosure, port (or slot) depth and width, and tuning frequency for the best scenario for you.

I took the 1.25 sq foot recommended enclosure for my type-x 10" and reduced it to 1.0 cubic feet, by giving up a few Hz of the tuning frequency and modifying the recommened slot parameters to a 2" diameter port. This saved me some space in my Miata. The bass hits just as hard. Using WinISD will basically do all the math for you and give you a graphical tool to "see" what your sub will sound like in that box.

The tool has a whole crap load of parameters you can tweak with (more than most people ever care to know), but the only TS parameters you really need to have, if I'm not mistaken, are the qms, qes, qts, fs and vas. You don't need to know what any of this means, just get these specs from your sub's owner's manual or manufactures web site.

Download WinISD or WinISD Pro at: http://www.linearteam.dk/
 

allende5
Unregistered guest
JeremyC, I think he plans to put them in 3 different enclosures, if that's what you mean by cancellation. It's actually not a bad idea. It would be sweet if he got a 4/5/6 way active x-over and optimized each sub for a particular frequency range. Depending on the sub, he can put the 8" in a sealed enclosure and run it at the higher mid-bass to bass frequencies. Set up the 10" in a ported enclosure and configure the x-over for bass to sub frequencies. Then set the 12" in a larger ported enclosure with a lower tuning frequency to get ultra low sub bass.
 

Silver Member
Username: Jeremyc

Germany

Post Number: 682
Registered: Jun-04
The fact is all 3 subs will be playing in the same freq ranges, and that will cause cancelation. Even with a active x over there will still be overlaps causing peaks in his responce curve. Its the same theory as running two diffrent subs in a car, or running 2 subs in stereo instead of mono. Since none of the subs will be working "with the other" it will cause problems. He could get away with running an 8 and a 12, as long as he sets the 8 up to run mid bass, and the 12 for bass. Even then he is making things harder than they need to be.

I perfer to keep things simple. The more you add the more processing you need to get the responce curve close to flat. The more processing the more coloration you add to the music, and the more chances for problems.
 

Gold Member
Username: Fishy

Tamarac Ft.Laud, FL USA

Post Number: 1377
Registered: Sep-04
Lol, why are all these weird sub combos popping up all of a sudden? Must be some kind of strange virus going around, hehe.

-Fishy
 

Silver Member
Username: Jeremyc

Germany

Post Number: 687
Registered: Jun-04
I don't know but they need to come up with an anti-virus fast.

I think it just comes down to wanting more, and especially more than they can afford. If you look at it from a purely mechanical point of view it makes sense. The more speakers the more sound. But once you start getting into all the tecnical aspects, it gets really complicated. I think thats were alot of people get lost. They tend to think MORE IS (ALL WAYS) BETTER, and don't really see or understand the whole picture.
 

allende5
Unregistered guest
It's really not THAT complicated. Most subs only sound good below the 80Hz range. And many door speakers cannot "meet" that frequency range down to 80Hz with real power at high volumes. So the mid-bass (I don't know around 150Hz-80Hz) is often lacking. I see nothing wrong with trying to fill that need with a 4-way and a 8" woofer. Yeah, perhaps the 10" is not needed, but still I see nothing wrong optimizing the 12" from 80Hz to 50Hz (by way of box design, and combination of x-over and subsonic filter). The 12" can easily be optimized for 50Hz and below.

Of course this all depends on what subs he will be using, whether or not he has a good x-over & subsonic filter.

Before I ripped my system apart and rebuilt it, I took my car to Circuit City just to get a quick and dirty system installed (I didn't want to spend the time myself at first), and these idiots did not want to reconnect my EQ, because they were "obsolete" and the "HU has better EQ features built into it"! Hah! I bought the CDA9825 which has absolutely NO EQ functionality at all!

Some people enjoy the hobby aspect of building a system and not always want to go the path less traveled. Sure it makes it more complicated, but that's the fun part. Hell, I enjoy putting my system together and I don't even like today's music!
 

Bronze Member
Username: Kunit

Post Number: 16
Registered: May-05
I have the 8 inch and 10 inch in the same box. Its an old box for a home stereo. So i just bought subs to match the holes because I didnt know nething about building my own box. So i got the 2 subs for 60 bucks and through them in the box. They work suprisingly well. But...aftr reading you guy's posts, i'll prob sell the whole set-up and buy 2 12's and make my own box this summer. I figured the 8 inch would pick up the more punchier bass where the 10 would pick up the lower boomier bass. that was my thinking behind it. But i just have the 2 subs into 2 channels.
 

Gold Member
Username: Subfanatic

Walton, Ky

Post Number: 3869
Registered: Dec-04
no, see thats the problem, like when u mix thigns, like when u mix a ported box AND a sealed box, you dont get the sq of a sealed and spl or ported, you get the WORST of both worlds, same goes with subs, if you wanna learn more go to the amps section, and there is a thread called "another question for myself" its between me and fishy designing a box, it will explain why this is a bad idea
 

Gold Member
Username: Insearchofbass

Post Number: 2346
Registered: Jun-04
i dont like ported it moves too much air lol
 

Gold Member
Username: Subfanatic

Walton, Ky

Post Number: 3876
Registered: Dec-04
i like ported
 

Gold Member
Username: Insearchofbass

Post Number: 2347
Registered: Jun-04
i was being sarcastic of course
 

Gold Member
Username: Subfanatic

Walton, Ky

Post Number: 3891
Registered: Dec-04
oh haah, didnt catch that
 

Silver Member
Username: Jeremyc

Germany

Post Number: 694
Registered: Jun-04
I think you will be happier with that set up Butch, and it will be easer to design, install, and on the $$$
 

Bronze Member
Username: Seawolfe

Bismarck, ND USA

Post Number: 55
Registered: Sep-04
When you talk about sealed, ported and (you didn't but I'll add it) bandpass , what you are looking at is solid driving bass, harder, louder and lower bass and really hard and loud bass within a narrow frequency range. sealed boxes tend to be better with hip-hop and rock. ported enclosures are good for rap, raggae and such. Bandpass enclosures tend to get used for hard and heavy metal rock where the listener wants to isolate the bass more. In the end though, it's all in what your preference is for bass.

As to difficulty, ported enclosures aren't hard, but they are not for novice builders either. If you don't get the vent size and length right, you could end up over/under extending your subs. If you do go with building a ported box, go with allende5's suggestion of using winISD or winISD Pro to design it and make sure the port vent is exact. Oh, and sand the port vent so that the opening is not hard edges, but soft rounded edges.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 4023
Registered: May-04
As far as the technical aspect, sealed offers better transient response and phase response than ported. Distortion is actually higher than both ported and bandpass enclosures due to less cone control. Sealed is a natural enclosure for a car due to the cabin gain of a vehicle, the enclosures rolloff and the cabin gain of the vehicle level each other out pretty well and give a fairly predictable frequency response. Also, sealed does not lose cone control below it's resonant frequency like ported does. At resonance, excursion is typically at it's highest, thus distortion is at it's highest and the subwoofer lacks control. This is what causes any boomyness and frequency response disasters. Since sealed boxes have a fairly high resonant frequency when compared to ported boxes (usually 40-50hz), this happens in the meat of the music and requires some EQ to level it out. Anywhere below that frequency, the enclosure rolls off at a rate of 12db/oct (just as a crossover would). That is where cabin gain takes off and levels things out, and how it does so depends on the vehicle used.

Ported enclosures have worse phase response and transient response than sealed. At certain frequencies, you'll get cancellation and boost due to the port being out of phase with the woofer. This isn't as big of an issue with subwoofers as it would be to a midrange, but it is still there. They have increased mechanical control around it's tuning frequency, anywhere above it's tuning frequency it will perform similarly to sealed with excursion characteristics. At it's resonant frequency, excursion is at it's lowest, meaning reduced distortion and also increased SPL due to the activity of the port. This also means that a ported enclosure is capable of handling more power, due to both the mechanical control and the increased cooling of the voice coil due to air being able to move in and out of the box. Due to that, SPL competitors pack power onto the driver at tuning, because excursion is at it's lowest at that point, it means you can keep adding power, getting more and more excursion while still not stressing the mechanical limits of the sub (however, it DOES stress it thermally, so they are limited to short burps). This, of course, continues to increase SPL at that point until eventually a limit is hit. Port noise, or "chuffing" can occur in a ported box, this is especially a problem if you don't have enough port surface area for the job. There will always be some coloration, but it is minimized with a good design. Below tuning, a ported enclosure loses cone control and basically performs as an infinite baffle (free air) application would. It is best to use a subsonic filter to combat this problem. In a home, ported boxes are natural because they offer a lower resonant frequency than sealed, also a flatter frequency response when in a room, all the way down to the resonant frequency (which is the tuning frequency). In a car, however, since you have cabin gain, it boosts the output of ported that much more and results in more SPL, which of course has the tendency to overemphasize certain frequencies and result in a boomy or overpowering response.
 

Bronze Member
Username: Xtant1001

Post Number: 64
Registered: Apr-05
I am selling 2 NEW 12inch Diamond D6 Subs. I am asking $325.00 plus shipping Per Subs. These are the new line of Subwoofers from Diamond. These Subs are still in the factory box and never been Used at all.

Also I still have my Xtant 1001 that Im also selling and asking $600.00 plus shipping for the Xtant 1001. The Xtant I just got back from factory also so it is in good condition.

The Pioneer Double Din I am asking $100.00 plus shipping for it.

2 carpeted Enclosure Fiberglass Box which weighs less then 5 pounds asking $125.00 each plus shipping.

Email unan0@hotmail.com or call (425) 985-5415 if interested. I can take Paypal unan0@hotmail.com but please add 3% for the fee, or contact me for other arrangements. Thank you for looking.

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Gold Member
Username: Jonathan_f

GA USA

Post Number: 4024
Registered: May-04
xtant, just to help you out, you may want to put those up on www.caraudiocentral.net, they have a for sale section on the site and fairly frequent traffic, may help you sell it a little quicker.
 

Bronze Member
Username: Xtant1001

Post Number: 67
Registered: Apr-05
Hmm thanks I just need to get rid of these. The subs are basicly brand new and the amp mint condition. They are just sitting in my garage not doing anything. heah besides I need the money. So any offers for the amp and cd player welcome but the 2 brand new subs Im pretty straight forward on the price.
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