Sealed or Ported Storage Enclosure?

[S-Man]

I'm going to make a sub enclosure for my A-Cab Storage Compartment.
Should i make it sealed or ported?
I'm planning on having a 10" sub.
As far as sound, whats the difference in having a sealed enclosure, verses a ported one?
I did a search and could not find an article on this particular topic of "sealed vs. ported"
thanks in advance for any help.
P.S. JnEsPappa, this has your name all over it

[supritdeol]

go with sealed, there is not enough room (volume) in the storage compartment to run a ported subwoofer. I would recomend completely sealing the compartment with fiberglass for better sound quality.

[S-Man]

I don't understand how a Ported enclosure would'nt have enough "room". The reason for the port is so that the air can escape right? I can see the sealed enclosure not having enough room. But what would it sound like, a sealed storage compartment vs. a ported one?
Also, i do intend to use fleece, and fiberglass for added strenth, and an mdf baffle/mounting plate.
thanks for the suggestions superitdeol.
can somone explain the aforementioned question? thanks.

[craigferriter]

I don't understand how a Ported enclosure would'nt have enough "room". The reason for the port is so that the air can escape right? I can see the sealed enclosure not having enough room. But what would it sound like, a sealed storage compartment vs. a ported one?
Also, i do intend to use fleece, and fiberglass for added strenth, and an mdf baffle/mounting plate.
thanks for the suggestions superitdeol.
can somone explain the aforementioned question? thanks.

Ported typically equals lower bass, better for rap, etc. Ported boxes must be bigger by around 50% than sealed. A sub in a ported box will require less power to drive, but can be blown easier. A sealed enclosure requires more power, is more diff to blow and doesn't dip quite as low. However, is very good for rock and some rap.

[MadMax1019]

I also don't think you will have enough room in your ac cab storage compartment for a proper ported enclosure. In my experience, a ported sub will sound louder b/c it tends to move more air, also it will sound punchier. But hell if you are good with fiberglass I'd say try a ported enclosure. I'm sure everyone in the audio section would love to see it.

- Max

[longwoodklon]

Ported typically equals lower bass, better for rap, etc. Ported boxes must be bigger by around 50% than sealed. A sub in a ported box will require less power to drive, but can be blown easier. A sealed enclosure requires more power, is more diff to blow and doesn't dip quite as low. However, is very good for rock and some rap.

Exactly. Ported is a great way to go if you have room. You need more room with ported because the port length determines the fundamental frequency. The longer the port, the lower it will play. There is a free progam used for designing enclosures, especially ported ones. It's called WinISD, search around and you should find it. And it's wise to run a subsonic filter with ported, because once you try playing a note that is lower than what you ported for, you are essentially running at free air and you will likely blow your sub. Sealed is your only realistic option for the storage compartment. /Mike

[rytherwr]

Exactly. Ported is a great way to go if you have room. You need more room with ported because the port length determines the fundamental frequency. The longer the port, the lower it will play. There is a free progam used for designing enclosures, especially ported ones. It's called WinISD, search around and you should find it. And it's wise to run a subsonic filter with ported, because once you try playing a note that is lower than what you ported for, you are essentially running at free air and you will likely blow your sub. Sealed is your only realistic option for the storage compartment. /Mike

Lottsa good answers to the question, and for the size of the storage compartment, you should go with a sealed enclosure with some fiber in it. Low frequencies are all about moving air, so get a sub with the longest throw you can find. Now to the meat of the question.....Good speaker enclosures must be designed to fit the electrical and mechanical properties of the speaker you are going to use. All good woofer manufacturers will also provide optimum alignments for their woofers, so all you really have to do is determine if you have the room to make the enclosure. When you are measuring for the size, you must take into consideration the basket and magnet and add it to your optimum enclosure size because it takes up room inside the box. Sealed enclosure alignments are much more forgiving of box size than ported boxes. In order to design a use-able ported box, you MUST either get the recommendations from the woofer manufacturer, know the speaker properties or be able to measure the speaker properties. Most of us hackers don't have the equipment to measure that stuff, so taking the advice of OEM's is very useful. My experience has been that there isn't enough room in the storage compartment to make a workable vented box. Hope this helps......)

regards
Wayne

[S-Man]

Exactly. Ported is a great way to go if you have room. You need more room with ported because the port length determines the fundamental frequency. The longer the port, the lower it will play. There is a free progam used for designing enclosures, especially ported ones. It's called WinISD, search around and you should find it. And it's wise to run a subsonic filter with ported, because once you try playing a note that is lower than what you ported for, you are essentially running at free air and you will likely blow your sub. Sealed is your only realistic option for the storage compartment. /Mike

Thanks alot guys. All these responses help me out ALOT.
Guess i'll be going sealed. I have a good idea how to build one from some pics somone posted on the classifieds here about a custom box they were trying to sell.[IMG]Box[/IMG]
Its made from MDF with fiber, and its removable so i don't have to stink up my cab with resin fumes.
Any recommendations on wattage handling, RMS, and so forth?
I don't want to blow peoples clothes off, wait, that might be kinda cool...
no, i just need to have a nice clean addition to round out my mids and highs.
Thanks.

(I can't figure out how to post a pic on the msg, so i'll just upload them.)

[wernerlab]

I think these guys pretty much nailed the answer. If you did port it it's likely the port would be noisy or it would be tuned so high (50-75hz) that it would be boomy and kill the low end bass. (or both)

Sealed has less group delay so it sounds more accurate. Not a rap 808 kick drum mind you but bass guitar, real drums, etc. will sound realistic. Not that same old tone (boom boom).

Thanks alot guys. All these responses help me out ALOT.
Guess i'll be going sealed. I have a good idea how to build one from some pics somone posted on the classifieds here about a custom box they were trying to sell.[IMG]Box[/IMG]
Its made from MDF with fiber, and its removable so i don't have to stink up my cab with resin fumes.
Any recommendations on wattage handling, RMS, and so forth?
I don't want to blow peoples clothes off, wait, that might be kinda cool...
no, i just need to have a nice clean addition to round out my mids and highs.
Thanks.

(I can't figure out how to post a pic on the msg, so i'll just upload them.)

[rx7vert]

Ports also have to be tuned depending on volume of the box, x-max of the sub, and volume that the sub displaces. Ported boxes are VERY difficult to get right.

the port is not just to let air in and out, a port actually adds to the sound output. A 40hz tuned port puts out a constant 40hz sound wave that adds power to the sound from the sub itself. You cannot sepparate the two sounds when listening, you just sense that it is a slight bit less accurate sounding than a comperable sealed box.

The only way to get great sound quality out of a ported box is to tune LOW like 32hz. In order to do that well you need a very large box.

A good ported box for a 10 would be AT LEAST 2 cubic feet. There are some programs that can give you the exact port demensions for your box, but they are pricey.