I posted here:

https://www.ranger-forums.com/forum2...ghlight=vented

but didnt get many replies. I am about to buy my box for my sub, but I cant make up my mind.

I am wondering what would be better. I guess this is where it turns into opinions more than what actually is better, but I dont care. Opinions please.

Sealed or Vented?

I like Vented, but I heard a good Sealed box tonight. Please help!


Adding a bit more:

My sub for my computer is vented and thunders real loud just for a 6" sub. Now I know this is different than something in a car or truck, but it really makes me like a vented set up. My home theater is also vented.

Last night, I went to Circuit City to talk to a friend and he showed me one of the installer's cars. He had the Type E Alpine subs in a sealed box and they sounded good. I was really impressed.

So, because of this, i am having a hard time deciding. I listen to ALL types of music, so I want something that doesnt discriminate against any form of music/bass.

 

i'd stick with sealed then, if you plan on listening to lots of different music. sealed will create the most accurate (close to accurate) sound... whereas, vented will allow you to hit the lower notes, and not be as tight as possible. i've had a few boxes of both, in many different ways... my favorite is sealed, for the same reasons..i listen to a variation of music, and sealed just does the job the best that it's able to be done.

 

Total agreence^

Sealed is for every type of music that you want a nice bass hit to, where as ported is for like rap where lyrics don't matter you just wanna gring on "yo biznitch" to a thundering beat. knaaaah Mean!

sealed still sounds great with rap just not like a mallet to your diaphram

 

This is the sealed box I am looking at (probably just going to buy because I am too impatient to build my own):

Sealed (i need 1.0 cu. ft. for the sub for sealed. this one will also match my interior better.):
http://cgi.ebay.com/12-SEALED-3-4-MD...QQcmdZViewItem

Vented (i need 1.75 cu. ft. for the sub for vented):
http://cgi.ebay.com/ONIX-12-SINGLE-S...QQcmdZViewItem

 

ive owned both.. in my opinion, the sealed has a sharper and tighter sound, and the vented box is usually a lot louder. it depends on if you want the neighborhood to shake or you just wanna shake. lol

 

Im not looking for anyone to shake. I am looking for best sound with all music.

 

Sealed boxes sound soooo much cleaner/more crisp.

 

You have 1 Rockford HX2 10, so sealed may not give you the loudness you are expecting. As everyone else has said, sealed is your better bet with alot more sound quality being involved. I'd go with sealed, as mine are. My subs can hit ANY frequency from about 18htz (which is pretty much the lowest freq that humans can actually hear) to whatever I have the crossover at at the time. I also have filler in my boxes which helped a little.

 

Sealed.

 

Sealed.


X2

 

I have a vented box. i rock the neighborhood! lol i like vented better

 

The choice is dependent on speaker. But usually it's more of a size, frequency response and efficiency tradeoff as far as what choice you make.

Vented enclosures, for the same size are more efficient. Why? Because the exact design of the enclosure creates energy from the BACK of the speaker which is normally "wasted" when a sealed box is used.

First, lets look at why we enclose a speaker in the first place, something very few people even consider. It's amazing how many folks I've met who claim to be "speaker experts" who can't even explain why a speaker needs an enclosure.

The most important reason is the nature of sound in air. Sound travels as a "wave" that consists of alternating areas of compressed air, and reduced pressure air. A speaker works by moving out to compress the air, and back to reduce the pressure. The domains of pressure/rarefaction travel out from the speaker as sound.

Now, a very important thing to note is that the back of the speaker is creating a zone of rarefaction (suction) while the front is compressing. Without something to keep them apart, the speaker "talks to itself" and the front and rear sound waves CANCEL each other. This is why a speaker sounds weak if not "baffled".

In fact, that's what the enclosure for a speaker is called -- a baffle. The "theoretical reference" is the so-called "infinite baffle" -- a wall stretching to infinity around all sides of the speaker. Such a baffle completely separates the rear and front. But as you can see, if we are on one side of the wall, the "work" the speaker is doing behind the wall is completely lost to us.

Let's leave that there for a minute, and talk about speaker loading considerations. By loading, I mean what kind of work the speaker "sees" when it operates.

When we enclose a speaker in a "real" box, not a theoretical one, the conditions change. For instance, the rear of the speaker now is working into a small space, relatively speaking -- so what's happening in there?

In a sealed box, there are two basic things happening:

1) The speaker, when it moves back, is acting like a "compressor" to the entire box (not just making a sound wave) and when it moves out, it is "sucking" on the box. This takes a certain amount of energy to make happen, and it is essentially "wasted" energy. This is in ADDITION to the energy needed to make the sound domains in the first place.

2) The sound domains that are created inside, reflect off the box and hit back on the speaker cone. This can reenforce it's movement, or resist it. If the sealed box is not of the proper volume AND proportions (both are important), the quality of the sound and smoothness of the frequency response will suffer.

Now, we can see that a sealed box can be a liability, but it can also be a benefit. For instance, there is a class of speaker called "air suspension" that have such floppy surrounds and spiders that they don't return to center by themselves very easily. These speakers make use of the air pressure in the box to act as part of the "spring" that controls the speaker cone movement.

Sealed boxes, properly designed, usually provide the smoothest frequency response over the widest range. However, they usually require a larger enclosure to get that.

Okay, so lets look at a broad class of boxes often called "vented", but more PROPERLY called "PORTED". These enclosures have a "hole" of some kind that allows the rear energy from the speaker to "add" to the front energy for greater efficiency (which means more volume). They include ports which are simple holes, holes with tubes behind them (including the Bazooka), and "passive radiator" systems like the BassLink.

All of these ported systems have one thing in common -- they increase efficiency. However, without a very good design and a quality amp, they are usually unsuitable for "air suspension" speakers. They simply don't retain back pressure well enough.

So what's the disadvantage of them? They can be a real pain to tune properly. They are very sensitive to speaker mass and area (which varies from speaker model to speaker model, manufacturer to manufacturer, even among ones that are allegedly the same "size").

If not tuned properly, ported enclosures are prone to be full of "resonances" that come and go thoughout the frequency range. You've probably all heard such systems. They hit real hard on some notes, and much less on others. Often they can sound "stuffy" or "boomy" and lack "definition" in the bass. This is the sign of an improperly matched ported enclosure.

Basically, you can't just buy any old enclosure and match it to any speaker that fits it. That's a recipe for a sucky system. You can get lucky, and then you know a combination that works -- but it's far better to make use of the tutorials and manufacturer data that is available to get the RIGHT enclosure for a speaker.

Finally, something about acoustical stuffing materials. There is a LOT of misconception about that.

1. Acoustical damping material is there to absorb the sound. -- FALSE. It is there to "slow down" the wave fronts and make the enclosure slightly "larger" acoustically. Basically, the low density media (don't substitute "foam" that is high density like seat cushion foam!) forms a "barrier" to the propagation of the waves and makes it take longer for them to move through the enclosure. This helps improve performance from smaller enclosures.

2. More is better. FALSE -- the right amount is what works. Sometimes, you can tune the enclosure for a speaker by putting in more or less of it.

3. It should always be in the center, as a loose "block" -- OR -- it should always be fastened to the walls. No absolute answer here. If the goal is to slow ALL the sound down, it should be in the "space" of the enclosure where it will effect both reflected sound, and slow the sound going to the port. If the goal is only to slow reflections, but not the sound going to the port, the material may be secured to the walls.

Anyway, the upshot of all this is basically this: speaker enclosures need to be the right one for the speaker, and appropriate for the application. Considerations of flatness of frequency response, size, and efficiency (volume for a given wattage) all enter in. There is no BEST enclosure.

Hope this enlightened a few of you.

 

Dang, thats awesome. I feel like i just read an article in a science magazine.

So everyone knows, I decided on a Vented/Ported box. I read articles of people that have the sub I bought and what they used and what they had to say. I played several different songs from different areas of music on both my computer and on my home surround sound system and they all, to me, sounded better when i kept my hand off of the port of the box. Now I know I didnt get the best sound from the box by doing that since the box is designed to be ported and operate as ported, but I feel it gave me a decent idea of what the music would sound like ported.

Anyways, I will take pictures when i get it all installed. If worse comes to worse, I can make a sealed box pretty easy. I will give this one a shot first.

 

Sounds good. I'm not downing either type -- just have to find what works for you as each has potential pitfalls and advantages.

About 30 years ago I got into designing enclosures, but I haven't done any of that for 25 years or so. In the meantime, the "parameter sets" that characterize speakers have changed and I'd need to reaquaint myself with the new design rules before I'd take a crack at it again. The basic principles haven't changed, but the numerical manipulations to design the enclosure have.

If you end up unsatisfied, take a look around for tutorials on proper enclosure design and take a crack at it. It's very rewarding when you end up with something that sound really good because it was designed for exactly what you wanted out of it.

Thanks for the comment though!

 

Somebody correct me if I'm wrong, but don't sealed boxes hit the lower notes better than a ported box? I just went from sealed to ported with my re se12" and the sealed box hit a little lower.

 

Yes, sealed will make it able to hit lower notes. A vented is going to be tuned for a specific frequency, which can be low but not as low as a sealed box can do. But generally I think sealed will allow for lower frequencies.

 

a vented enclosure has a much steeper roll off once the F3 point is reached. compared to a sealed enclosures 12dB roll off, the vented box is a 4th order desgn, which has a 24dB roll off. this means that the F3 point becomes more critical in ported enclosure design as two things happen once the F3 point is reached. if the F3 point of a given speaker is say, 45Hz, any sound below 45Hz will qickly decrease in output and the woofer will react as if it has no acoustic suspension (basically, the woofer wont see the enclosure any more). this will cause serious overexcursion below the F3 point.

an F3 point is how low the enclosure will play, given the woofer's T/S parameters, and calculating correect numbers from them.

with all of the good info given so far in this thread, let us know what sub you are using. finding the efficiency bandwidth product will let you know mathmatically if the sub will be better suited for a sealed or vented box. (with out the hassle of trial and error!)

 

Sub:

http://www.onlinecarstereo.com/CarAu...roductID=14954

Box:
http://cgi.ebay.com/ONIX-12-SINGLE-S...QQcmdZViewItem

I am hoping its ok. If not, I know I can build a Sealed box easier/faster than a Ported box.

 

Fs (Free Air Resonance)- 29
Qes(how efficient a speaker is electrically)- .5

EBP (Efficiency Bandwidth Product)= Fs/Qes

so, 29/.5= 58
-------------------------------------------------------------------------------
Simple Rule of Thumb when looking for the best box for a certain sub:

if the EBP is below 50, a Sealed box would be the only way to go.

if the EBP is 50-75, a Sealed box is reccommended, but, a vented may be pulled off.

if the EBP is 75-100, a Vented is recommended, but, a sealed may be pulled off.

if the EBP is over 100, a Vented would be the only way to go.
------------------------------------------------------------------------------

your EBP is a 58. that's just over the 50 mark. personally, i'd go straight for a Sealed, seeing that the sub wasn't meant for a Vented enclosure. but, using that rule, it is doable. so, if you were looking to go vented, and have already got the box, give it a shot. you may love it, or may find that it isn't you. like i mentioned above, your taste in sound is different from everyone else's, so it's up to you in the end to know weather or not a vented box will sound right. (assumming the box was built right according to specs of the sub)

if you go ported, i'd suggest building it yourself so you know it's correct. that ebay box doesnt' give much info, it only says total box volume. nothing about the vent... so im not sure if it would work or not.

 

How did you get these numbers?

 

found the Fs and Qes online at a few different audio sites.. Alpine's site is horrible in that they show no helpful info, lol.. so i had to search around real fast.

 

Yes, those are based on the "newer" design methodology which is much more robust and accurate than the old system we used.

Ported enclosures can be GREAT for lower sounds -- but they have to be much bigger to do that than is probably practical for a vehicle.

The nice old "ported horn" designs like the old Altec-Lansing "Voice of the Theatre" systems combined a horn loading for higher bass notes, and porting for lower bass notes. However, just one of these speakers would fill your entire cab, lol.

And there are online sites to teach and enable designing your own enclosures, but I've not spent enough time on the subject to advise you. Looks like someone's been doing their homework though (Sean)!

 

So what's the disadvantage of them? They can be a real pain to tune properly. They are very sensitive to speaker mass and area (which varies from speaker model to speaker model, manufacturer to manufacturer, even among ones that are allegedly the same "size").

If not tuned properly, ported enclosures are prone to be full of "resonances" that come and go thoughout the frequency range. You've probably all heard such systems. They hit real hard on some notes, and much less on others. Often they can sound "stuffy" or "boomy" and lack "definition" in the bass. This is the sign of an improperly matched ported enclosure.

....MC Speakers is your friend.

 

ive never used a sealed box its all been ported for me, but as for going lower humans cant hear below 20hz, ive heard its actually 25 though so what do you need a sealed box to go below that for, you would be surprised at how many songs even go below 35hz, and only a handful get in the 20s, if you tune a ported box to 30hz you would be able to play down to about 25hz safely, but you wouldnt use it much anyway, i would rather have a ported box so i could use the extra loudness if i need too, and lets say you tune a ported box to 32hz you would have way more output from 28-60hz ish

as long as its no wierd shape box i can design one for you

 

Ha ha! Yes, you "feel" rather than hear the really low stuff -- though that can be cool too. I don't have anything that goes that low in my truck though.