Sound Quality: The Sealed/Ported misconception

[DBfan187 5,000+ posts]

Sorry geolemon, I have no Money right now but I'm sure someone else would buy it from you! post an ad w/ pics in the CAF classifieds, or maybe ebay? You should start up a business for making custom enclosures, maybe Home Theater?

 

[geolemon 10+ year member]

So basically you people believe that sealed enlosures are the best, because one man used a dictionary to write a post. Non of you will explain why a sealed struggles to play wave bass, yet carry on like sealed is end-all.

There was no dictionary involved.. in fact no big words really involved at all.

There was no need for reference, this is all common knowledge that as Josh said, hasn't changed since the advent of vented enclosures themselves.

There's no mystery as to how they operate... and my points were addressed to you, with my points regarding how a vent is not a "hole in the box".

If you read the post, I assure you, you will understand the post. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Foolish talk about this silly sealed = SQ. Thats elementry train of thought. Some highly respected member of audio decades ago, was probably at a cocktail party and just said "You know, sealed is the best SQ, because I say so". Then everyone just said "Ya he's right, sure sealed doesn't play the low end the way music producers intend, but he must be right". Notice in music studios, producers use ported/vented speakers (But I guess you guys know more than music producers).

First off, my point was that neither sealed nor vented are superior."superiority" of enclosure type is primarily determined with respect to a particular subwoofer driver...

And your subwoofer driver is primarily chosen based on your listening goals (one of the factors being whether it is ideal in the type of enclosure that best suits your goals). //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

You apparently are also fundamentally misunderstanding what "Cabin gain" is.

In a small enclosed space, you get a natural rise in bass response - to the order of about 12dB/octave, beginning at some frequency roughly coincidental to whatever frequency's wavelength corresponds to your interior's longest dimension.

So, in a small enclosed space like a car, where you have a "cabin gain" phenomenon causing your bass response to naturally rise by 12dB/octave, you want a sealed box, with it's early-beginning, and slow-falling roll off...

Because when combined with your "cabin gain", you actually end up with an "in car response" that's nice and smooth, just like the sound engineers intended..

In a studio, or any large space, you don't have this phenomenon. Likewise, in a large space, your actual response tends to be closer to that "anechoic response" (the response plot you see when you model subs up in software).

So in that application, you often wouldn't want a sealed subwoofer's response, with it's low-end roll off.

It's all in matching the subwoofer, and enclosure type, to your particular application. Something that you are not only demonstrating an inability to perform, but even comprehend, by nature of this very example you gave.

Read up on "Cabin gain" and "transfer function" (as I mentioned before //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif ).

It's funny to see you guys talk yang, just admit that your hurt that vented does more justice for low-end and stop your dictionary foolishness. It's a good thing you guys don't have anything to do with PA and home and car SPL. Audio would be dull and dead if that was the case. Sealed is a just a woofer -deadening- enclosure for people who can't handle 808 bass.[/color]

It's honestly quite amusing to hear you talk "snake oil".

Again, as far as "vented doing more justice for low-end", that depends on your application.

If you mean in a large open space - then yes.

However in a car (this is a car audio forum), cabin gain conspires against you.

In car, your extension of the response will create a 12dB/octave rise, due to cabin gain, that will simply boost your low end disproportionally.

That, by nature, is why "boom cars" exist. Because of that natural, acoustical phenomenon, known as 'cabin gain'. An acoustical bass boost.

Some guys want this unnatural, exaggerated, disproportional bass.

But that's not a sign of superiority, in terms of [/i]sound quality[/i], which is what you are touting.

And my statements aren't meant to indicate that you can't get good sound quality out of vented enclosures either - I run vented enclosures in my personal car.

But I'd never make a generic claim that ported has better sound quality properties - it simply doesn't, it can't.

 

[geolemon 10+ year member]

Sorry geolemon, I have no Money right now but I'm sure someone else would buy it from you! post an ad w/ pics in the CAF classifieds, or maybe ebay? You should start up a business for making custom enclosures, maybe Home Theater?

lol... good idea, but I've got my hands full starting up a business manufacturing car audio products already! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[DBfan187 5,000+ posts]

Notice in music studios, producers use ported/vented speakers (But I guess you guys know more than music producers).

You might have a point here. Maybe we can get the music producers to make better music!

Right now, some/most of our music SUCKS!

 

[DBfan187 5,000+ posts]

geolemon, Maybe you could expand you business?

 

[geolemon 10+ year member]

You guys follow fashion like lemmings off a cliff and may never get it. I don't care about some judge.

lemmings follow blindly, that is, without fact or science.The rest of us on this forum are citing facts, physics, and acoustics that are not simply theoretical, they do not only exist in textbooks (although obviously they do!), but are easy to apply and test and observe. Most of us have both sets of experiences.

I'd tend to ask how you think your words transcend the words of acoustical engineers, scientists, and famous researchers, who have written those textbooks?

I sincerely hope it's not because of this misunderstanding:

Tell me why a sealed struggles to reproduce the -boom- if it isn't the sealed suspension. You people can never tell me, so what do you got. I bring up points and prove them and you guys just gather in numbers and follow the guy who read a book. I'll tell you something, only one of you actually probably read the first post, then the rest of you just jumped on his opinion.

This has everything to do fundamentally with sealed vs. ported enclosures. Fundamentals. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif
Primarily, it has to do with frequency response shape:

1) Ported enclosures yield greater output, as the port allows the rear-of-cone energy to escape via a small mechanical delay, allowing it to combine constructively with the front-of-cone energy. This delay boosts SPL, the sacrifice being an inherent slight smearing of the sound quality due to the phase difference between the port and the cone.

2) Ported enclosures allow the designer to either design an anechoic response that extends very low, or to design a peak into the anechoic response (which is what software shows you).

When installed in-car, the "cabin gain" (again, read up on cabin gain //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif ) turns that anechoically-flat response into a 12dB/octave increasing curve (in the case of the former), or exaggerates and magnifies the bass-boost built into the response (in the case of the latter).

Both of these reasons boil down to a ported enclosure's natural increase in SPL compared to a sealed enclosure, and potentially a focused increase in SPL at a particular frequency range (as opposed to a general sloping increase).

By nature, the very trade-offs made to obtain higher SPL will cause tangible, unavoidable compromises in sound quality.

Arguing that your rap music "hits" harder with a vented enclosure?

No one would argue that.

Arguing that sound quality is "truer" to what the recording engineers layed down on the recording with a vented enclosure, in a car?

That's almost ludicrous.

Go back to school, learn how to read an entire post, then you will sound more intelligent in reply.

Hello, Mr. Pot! I'm Mr. Kettle, and I'm thinking that your blackness is covering your eyes...Somehow, something is preventing you from comprehending the unanimous responses simply stating that there's no facts behind your words, yet that you are simply waving misunderstandings of symptoms and effects as if they are facts themselves... //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[geolemon 10+ year member]

geolemon, Maybe you could expand you business?

Enclosures are in the plan... but there will be higher sale volumes than I could crank out by hand... and of course, I want to do some more interesting enclosures than the typical stuff... Can't really say any more at this point though. //content.invisioncic.com/y282845/emoticons/censored.gif.f9ad8e7c6db58c5530c5a0a20a3b5baf.gif

//content.invisioncic.com/y282845/emoticons/nerd.gif.c6fa51ddf7ff75f1c0371fbc648f70ae.gif

 

[nweibley 10+ year member]

Below 30, just for the record, I tried something for you. I have two friends with JL Audio 12" W6s, one I buildt to exacting JL sealed standards, one to exacting JL ported standards. Both boxes were built by me, and honestly perform excellently.

We ran about 10' of 8 ga wire from the same amp to a fully carpeted room in my house (through a window), and loaded the area up with pillows and cushions to deaden any reflections and get the true bass, straight from the woofer.

Here is what we concluded:

Ported... rap does sound boomy, yes. Rock, could be slightly better, but still sounded very good, but I could hear the driver getting a little side-tracked as we cranked it. It was there, but you wouldn't notice it unless you have an SUV and the box facing you. Classical was good, and it was nice and low. Frequency sweeps from 150hz-18hz showed a few spikes in output that were annoying, but not that bad. Output was really good for such low excursion... overall it sounded good and was very acceptable.

Sealed... rap wasn't nearly as boomy, but still sounded appropriate. It could have used a little bit more output, but hey, we had pillows everywhere, so it isn't totally realistic. Rock sounded great and was reproduced very well, and for the most part, the sub had no extraneous noises. Classical was tight, but was playing lower than the ported box was. Sweeps were very flat, I counted one noticable spike in output. Output was a bit short of the ported, but it was still plenty loud for the user who just wants to augment their low-end.

So there you go... no math, no equations... just real boxes.

Ported gave me a bit more output with some nominal noises and a less flat frequency response.

Sealed flattened things out, but lowered output. All that I heard was bass though, no noises that didn't belong.

-----Nate

 

[Below 30 10+ year member]

Nice one mang, you see what I mean about rap in the ported. The boom in certain tracks is supposed to be there and you here it much better in ported. You represent class to me, because you did the experiment like me and know what your replying to.

Only 1000 times do I have to keep saying no box is the best. The point of this thread was if sealed doesn't play the boom from hip-hop like vented, it isn't reproducing the track as it was meant to play. Therefore sealed is not end-all-be-all. Respect to you.

Now for the super-limp jackassess. You talk about kiddy forums I am from. Nice one, seriously it would stick except for one problem. Look at this forum everyday. Pure losers asking the same tired question "Is flea market speakers good.", "Is $50 CDN too much to spend on a good sub."; "This sub vs that, which is the best". Think before you talk, your the one who has been apart of a kiddy forum for years.

More proof that most of you never read my posts, is when one of you was asking whats -wave- bass and carrying on like a loser. Clearly my first posts said it's called boom; extended; or wave bass. That extended boom sound you hear from generally rap music.

Yes, use vulgur language, it's better than seeing "retard". If your going to use negative words, just use grown-up words is what I'm saying.

 

[CELLERBR 10+ year member]

I guess you mean grown up words like "super-limp jackasses" and "mang".......... //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif If only I had a quarter for everytime I someone told me I sounded childish and immature for not using those words........................I would be one poor S.O.B.!!! in your ORIGINAL post you stated that a sealed box should not be called an SQ box??? This is where you screwed up (well one of many times), that statement is simply dumb, almost as dumb as your reproduction of boom angle you have been taking....You talk about hip hop/Rap and boomy bass as if they held any merit in the SQ world at all....What you are failing to comprehend (that means understand) is that boomy bass is considered bad in terms of SQ....So your whole point and theory is shot down right there.....Apparently you have never heard a good sealed setup....Although not as loud as a ported setup still very loud (with the right driver and power) handles the LOW notes much better then ported while playing much flatter less boomy (which is a good thing!)

So I am assigning you some homework......

1> By and read (or have someone capable read you) at least a 5th grade english book...

2> Once you feel comfortable speaking coherently and in full sentences, buy a physics book and study it also a music theory book wouldnt hurt you either but that is for bonus points...

3> By the time you complete this you should have some sort of a grasp on these things then you should change your screen name (because your current name is forever tainted with ignorance) and talk with us some more.

Or

3> If at this point you still think you are right and still can not communicate like a normal human while refraining from using phrases like "super-limp" and words like "mang".....Seek immediate professional help (and yes by that I mean you should sign up to test shark repellent and things of this nature)

 

[Below 30 10+ year member]

The words I use are more original than "retard". Don't forget you hate hip-hop, so you don't even know what to listen for. My point was, if sealed is SQ, then vented is too. If vented isn't SQ, then sealed isn't either. Thats some stupid logic to call any type of box SQ.

Its like saying only 5 foot 10, 110 pound girls look good. That is dead wrong, on MTV/Much Music you see pure girls with fat ***** and large breasts, who eat well, which I like. So its the same with a box type, people who like rap will lose the -boom-, which takes away the SQ potential from sealed. Rap/hip hop is the sole reason car audio is as hype as it is today, no question.

Only people who big-up sealed like its god, is people like you, who think Rap producers are monkey's. For the rest of us, ported//vented is no more or less SQ than any other box. If rap producers are monkey's, then big names like Brittany Spears really like monkeys.

About the confusion on Vent, you people know what a vent is. It is a hole that allows air to escape, to release back-pressure or exhaust fumes. In my enclosure, instead of porting to a specific Hz, I vent all the rear wave, which is amplified against the wall. Look at Cerwin Vega 15" home box, do you see a maze of tubes in there, no.

I gave respect to the poster who built the 2 boxes and tested, because he did hands on comparison, like I did. You better realize I'm hands on, not fantasy land like you. While I'm causing neighbors to call cops for rumbling their home, you keep reading your books.

 

[jlaine 10+ year member]

I don't believe anyone wants respect from you, you are incapable of bringing any knowledge to this conversation at this point - all you are is another fanboy trying to gain attention.

You'd be shredded alive at an AES meeting, I suggest you see if the local college has one. I'd for one love to see you try to stick to your guns when surrounded by industry professionals in person.

Be sure to mention that you prefer vented and not ported enclosures...

And that sealed enclosures stop the speaker before it's supposed to... They'll love that one for sure too...

Time for you to unplug, it's time for a wake up call.

 

[jemorgan85 10+ year member]

The words I use are more original than "retard". Don't forget you hate hip-hop, so you don't even know what to listen for. My point was, if sealed is SQ, then vented is too. If vented isn't SQ, then sealed isn't either. Thats some stupid logic to call any type of box SQ.
Its like saying only 5 foot 10, 110 pound girls look good. That is dead wrong, on MTV/Much Music you see pure girls with fat ***** and large breasts, who eat well, which I like. So its the same with a box type, people who like rap will lose the -boom-, which takes away the SQ potential from sealed. Rap/hip hop is the sole reason car audio is as hype as it is today, no question.

Only people who big-up sealed like its god, is people like you, who think Rap producers are monkey's. For the rest of us, ported//vented is no more or less SQ than any other box. If rap producers are monkey's, then big names like Brittany Spears really like monkeys.

About the confusion on Vent, you people know what a vent is. It is a hole that allows air to escape, to release back-pressure or exhaust fumes. In my enclosure, instead of porting to a specific Hz, I vent all the rear wave, which is amplified against the wall. Look at Cerwin Vega 15" home box, do you see a maze of tubes in there, no.

I gave respect to the poster who built the 2 boxes and tested, because he did hands on comparison, like I did. You better realize I'm hands on, not fantasy land like you. While I'm causing neighbors to call cops for rumbling their home, you keep reading your books.

Why are you comparing girls to acoustics? You are such and idiot. I don't feel like taking this post and correcting everything, as everyone else already has.

 

[jlaine 10+ year member]

TAbout the confusion on Vent, you people know what a vent is. It is a hole that allows air to escape, to release back-pressure or exhaust fumes. In my enclosure, instead of porting to a specific Hz, I vent all the rear wave, which is amplified against the wall. Look at Cerwin Vega 15" home box, do you see a maze of tubes in there, no.

Cool... So you've either done INFINITE BAFFLE... or you've just ported your 15" home box Cerwin Vega to about 100+ hz...

That was an intelligent route to go. Of course if you knew about some of the basics surrounding enclosure design and driver acoustical interaction, you'd have known that, and called your mockup 'enclosure' exactly what it is, instead of trying to say you are releasing exhaust fumes.

 

[CELLERBR 10+ year member]

I think we have all already established that lower tuned vented/ported (one in the same) are more ideal for home enclosures! That was established way back in the thread......But since we are in the Car Audio Discussion>General Discussion forum it would only stand to reason we would be talking about car audio....And since we are then i still disagree with you and say that sealed is a SQ box.....And you know what...I have both I am running a ported box on my XXX right now!!! And can tell you that when I run my sealed box the SQ is BETTER!!!! So to reiterate: 1 - We are talking about car audio. 2 - Hip Hop is not SQ. 3 - Sealed boxes are for SQ. 3 - Ported boxes are for SQL/SPL. 4 - Ported boxes can not play as flat or allow the sub to be as responsive as sealed. 5 - I like hip hop/Rap just fine and listen to it regularly. 6 - I still realize hip hop/rap is not meant for SQ. 7 - You use made up words like "mang" then call other people stupid for using real words! 8 - You fail to realize you are not the only one here with "real life" experience others qoute facts from books, however have a great deal of "real life" experience probably more then you (definately at setting up SQ systems apparently) 9 - Who care what Britney Spears likes! (you think what she does is music???) 10 - No one is "bigging up" sealed boxes we are giving credit where credit is due and when it comes to SQ setups SEALED is where the credit is due...

-Ian