pros and cons of going ported

[paikiah 5,000+ posts]

humor me then

 

[sumone 10+ year member]

A vented enclosure's port tuning does not have to be mated with the car's transfer function...a ported enclsoure can be made to acheive a very flat in-car response if properly planned with the vehicle's tuning characteristics taken into account.

care to expand on how one can design a box as per your proposition?

 

[paikiah 5,000+ posts]

care to expand on how one can design a box as per your proposition?

in this case, I agree with audioholic. It's theoretically possible. The only problem is, a way flat repsonse might look great on a graph, but sound like ass in real life.

 

[sumone 10+ year member]

^ yeah I've heard the flat response sounds like ass with headphones thing. but if I wanted to make a ported box to get a flat response, what numbers would I have to add up/do some math on?

 

[audioholic 5,000+ posts]

Small sealed box or large, I don't care. It will still sound better than a ported box. I think there's ahigher chance of the sub bottoming out on ported, rather than sealed, no matter small or large.
High excursion, low excursion, what's the difference? If you play a high excursion sub soft, then it'll move only slightly. Then what? It won't like it? It's gonna sue me??

In the case of SQ, you don't need 29mm or whatever xmax of the sub. 8mm is more than enough.

I'm sticking with what I said, I prefer sealed than ported. (not into SPL anymore)

Okay, I'll humor you. Your general statement that sealed systems always sound better is absurd. Sealed systems can get very boomy, depending on the driver and enclosure volume. Ported systems can sound very tight, depending on the driver, enclosure volume and tuning freq.

You say there's a higher chance of bottoming out ported over sealed. Again, another general statement with nothing to reference. What volume sealed are we talking about? A large sealed enclosure can make for very easy suspension limitation issues. What tuning on this ported enclosure are you talking about? Are we using a subsonic filter? Etc. Under certain circumstances, like for SPL burping, ported enclosures actually can give the least cone excursion (playing at tuning), and you wont 'bottom out' your sub even with 10,000 watts.

Excursion, Im not even sure what point you are arguing with your excursion comment. Who in this thread said it would hurt a high excursion sub to play it at low volume where there is little excursion?

Id also like to know where you mathematically came up with the number of 8mm as all thats needed for good SQ. Let me guess, that's the excursion of the subs you own. lol j/k But seriously, ive seen arguements that excursion is needed for high SPL (which is true, in a ported application, playing at tuning), but Ive never seen anyone argue that lower excursion is better for SQ, especially in a sealed application. Added cone excursion increases displacement (obviously) which means more authoritative lows, greater output along the entire spectrum for sealed applications (as cone excursion is directly realted to overall displacement/output/SPL), and less distortion at any playing level due to not needing to reach as near its full excursion potential.

Take two subs. Sub A has 10mm of excursion, sub B has 30mm of excursion. Turn the volume up on both systems so they are excurting 8mm (all this just for example). Sub A is at 80% of its potential cone excursion, and the motor and suspention are stressing heavily, while sub B isn't even at a third of its excursion potential, outputing much less distortion as its stressing much less. So, at the same excursion, assuming the same cone area (to compare apples to apples), both subs are outputing the same SPL, but the sub with greater excursion is doing it with less stress/distortion. Are these large excursions necessary for good SQ? Not absolutely, SQ competitions are won every day by people with low excursion subs. Of course these competitions are at low volume levels. But, added cone excursion, if designed/implemented correctly, can be a benefit to the subs overall SQ.

That's all that comes to mind off the top of my head, already spent more time on it than I wanted to. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[audioholic 5,000+ posts]

care to expand on how one can design a box as per your proposition?

Its not rocket science. Instead of tuning the box to the same freq as the vehicle's tuning freq, thereby amplifying it even more, you simply tune the enclosure above or below (depending on the vehicle, its tuning freq, and your xover placements) the resonant freq, thereby nullifying the peak at the cars resonant freq.

 

[audioholic 5,000+ posts]

in this case, I agree with audioholic. It's theoretically possible. The only problem is, a way flat repsonse might look great on a graph, but sound like ass in real life.

This thread started out with people saying sealed enclosures are better due to the flatter response they give. Now a flat response sounds bad. You guys need to make up your minds. I agree a flat RTA doesn't sound good, but you do want a 'flat response' from your speaker system to start with. You can then process the sound (EQ) to tailor your sound wants/needs instead of EQ'ing simply to try to flatten out response peaks.

 

[audioholic 5,000+ posts]

^ yeah I've heard the flat response sounds like ass with headphones thing. but if I wanted to make a ported box to get a flat response, what numbers would I have to add up/do some math on?

Although I doubt you are seriously considering this, I will humor you too. You would start by mapping you vehicle's sound response along the frequency spectrum the sub(s) will be playing at. A pink noise generator, a speaker and an RTA would work well. The pink noise generator would play the same power to each frequency (thats pretty much the point of pink noise fyi), the speaker outputs this 'level spectrum', and the RTA would read the response, showing peaks and valleys. This would be your vehicle's response curve. If you dont have access to an RTA, a simple SPL tester like the ones sold at Rat Shack, and a piece of paper to write down the responses along the frequency spectrum will also work. The highest peak would be your vehicle's resonant frequency. You would then tune your ported enclosure using a box building program that graphs out response curves given the known enclosure specs and actual subwoofer being used. You would tweak it until you get a response that would, when combined with the in car response, give as flat a response as possible. Thats the trickiest part of course, and no doubt some in car testing and tweaking of the final design would be needed.

edit: one last FYI, some very well respected home audio manufacturers use ported enclosures for their subwoofer systems. Its not nearly such a black and white picture as sealed always sounds better. There is speaker design to consider, power available, desired response, listening environment, etc. Not to mention, by design, some subwoofers simply sound better running ported than sealed. The theil/Small parameters for the sub can give clues to this.

 

[paikiah 5,000+ posts]

you know, you really should generalise things here. Plenty of newbies here that won't be able to comprehend what you've just said, and will now become a parrot and say ported is just as good in terms of quality, without knowing the variables involved.

I'll STILL stick to my statement that sealed sounds better than ported, only this time, I'll add in general. Satisfied? Let's not bring EQ's. Make a box according to mftr specs, drop it in and power it. Till this day, I've not heard one ported that had better sound qualities over sealed (take out subs which only belong in one type of box). Perhaps it's my preference to hear subs in sealed, rather than ported.

Oh, almost forgot.

ur sub wont like the excursion.unless u have a HIGH EXcursion SUB. sealed will destroy ur subwoofer especially if u went to high vol. sub will easilly bottom out

This was why I was talking about high excursion subs. There's no need. Like you said yourself, SQ comps aren't about blasting music and don't take a whole lot to get to listening levels, thereby saying 8mm is about all I have seen people use.

And yeah, I do have subs that have an xmax of 8mm, lol~ but so does Focal's top of the line. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[paikiah 5,000+ posts]

Although I doubt you are seriously considering this, I will humor you too. You would start by mapping you vehicle's sound response along the frequency spectrum the sub(s) will be playing at. A pink noise generator, a speaker and an RTA would work well. The pink noise generator would play the same power to each frequency (thats pretty much the point of pink noise fyi), the speaker outputs this 'level spectrum', and the RTA would read the response, showing peaks and valleys. This would be your vehicle's response curve. If you dont have access to an RTA, a simple SPL tester like the ones sold at Rat Shack, and a piece of paper to write down the responses along the frequency spectrum will also work. The highest peak would be your vehicle's resonant frequency. You would then tune your ported enclosure using a box building program that graphs out response curves given the known enclosure specs and actual subwoofer being used. You would tweak it until you get a response that would, when combined with the in car response, give as flat a response as possible. Thats the trickiest part of course, and no doubt some in car testing and tweaking of the final design would be needed.
edit: one last FYI, some very well respected home audio manufacturers use ported enclosures for their subwoofer systems. Its not nearly such a black and white picture as sealed always sounds better. There is speaker design to consider, power available, desired response, listening environment, etc. Not to mention, by design, some subwoofers simply sound better running ported than sealed. The theil/Small parameters for the sub can give clues to this.

But how many people here (myself included) would be able to understand all about soundwaves and incorporate into building a box? I understand what you mean by building a ported box with the car's fs in mind. But how much of it would it be used in reality to people who don't own RTA"s and don't plan to either?
Lastly, how many SQ champiion vehicles have ported box, instead of sealed? No, I'm really asking. DOn't remember seeing too many.

Home audio, yeah, seen quite a few that isn't sealed. But car audio? Hmmm..//content.invisioncic.com/y282845/emoticons/popcorn.gif.32dd9e22fd77e77bc3c907062768fcd2.gif lemme go get some popcorn and watif or your answer

 

[audioholic 5,000+ posts]

you know, you really should generalise things here. Plenty of newbies here that won't be able to comprehend what you've just said, and will now become a parrot and say ported is just as good in terms of quality, without knowing the variables involved.
I'll STILL stick to my statement that sealed sounds better than ported, only this time, I'll add in general. Satisfied? Let's not bring EQ's. Make a box according to mftr specs, drop it in and power it. Till this day, I've not heard one ported that had better sound qualities over sealed (take out subs which only belong in one type of box). Perhaps it's my preference to hear subs in sealed, rather than ported.

Oh, almost forgot.

This was why I was talking about high excursion subs. There's no need. Like you said yourself, SQ comps aren't about blasting music and don't take a whole lot to get to listening levels, thereby saying 8mm is about all I have seen people use.

And yeah, I do have subs that have an xmax of 8mm, lol~ but so does Focal's top of the line. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Where did I generalize that ported enclosures have better SQ than sealed? Why would some read what I just wrote, then 'parrot' something like that? If anything, my posts point out that there are too many variables to make such statements.

As for if Im satisfied with your comment, my satisfaction isn't what's at issue here. You are still ignoring the fact that some subwoofers are simply designed to play in/sound better in ported applications. Read up on Theil/Small parameters for speakers, they can/do indicate this.

As for excursion, again it lends benefits to SQ in the propler design. I guess you missed those points I specified above? I wont re-write them. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif Why you quoted bass outlaw I do not know, his quote is quite misleading, if not outright wrong. From the best I can gather from his poor writing in that particular post, he seems to be saying a sealed enclosure will destroy low excursion subs because sealed enclosures 'bottom out' easily. Did I decipher it correctly? If so, its non-sense. Sealed enclosures dont necessarily bottom out subs easier, again depends on the enclosure in question. And, you can run either low excursion or high excursion subs in a sealed enclosure just fine. Cone excursion is not the determining factor in the type enclosure to use.

 

[audioholic 5,000+ posts]

But how many people here (myself included) would be able to understand all about soundwaves and incorporate into building a box? I understand what you mean by building a ported box with the car's fs in mind. But how much of it would it be used in reality to people who don't own RTA"s and don't plan to either?
Lastly, how many SQ champiion vehicles have ported box, instead of sealed? No, I'm really asking. DOn't remember seeing too many.

Home audio, yeah, seen quite a few that isn't sealed. But car audio? Hmmm..//content.invisioncic.com/y282845/emoticons/popcorn.gif.32dd9e22fd77e77bc3c907062768fcd2.gif lemme go get some popcorn and watif or your answer

How many would do all that is probably very few, which is why you see many sealed systems for SQ, and why you see so many people with the misconception that sealed always sounds better. Starting to see my point yet?

As for how many SQ champs use ported, I really cant say. I can say alot use ported midbass enclosures, for tuning/freq response reasons. Again, ported does not necessarily equal poor SQ, or even necessarily worse than if sealed were to be used. I can also say, when you can easily reach the necessary volume levels required for a sanctioned SQ competition with a simpler sealed system, why would you hassle with the more complicated ported setup just to gain the advantage ported enclosures have (higher output)? but, for a street vehicle that wants his SQ but as much output as possible at the same time, a SQ ported system might be perfect.

 

[luvinthebass 5,000+ posts]

please get back to the topic of the thread!

 

[audioholic 5,000+ posts]

please get back to the topic of the thread!

If the topic of this thread is not the advantages and disadvantages of ported enclosures, what exactly do you think the topic is? Its your post, you should know. lol

 

[paikiah 5,000+ posts]

Where did I generalize that ported enclosures have better SQ than sealed? Why would some read what I just wrote, then 'parrot' something like that? If anything, my posts point out that there are too many variables to make such statements.

You didn't generalise, that's my point. Some will now get so confused over the pros and cons of ported vs. sealed in GENERAL. That's what this thread is all about, right?

About you mentioning the variables, take out resonant freq of the vehicle, take out EQ's, implement mftr recommended specs , amps that produce the RMS value of the sub. (I am willing to go out on a limb and say there are many who would be feeding 1500~1600w to an XXX or brahma in a large ported box cause the specs said so, without thinking about the relevance of power handling and enclosure size/type)

Just how many of us look into the res freq of our vehicle's cabin (much less own an RTA)? More people would be using the res freq to build a louder box for SPL applications than they would to control the peak.

As for if Im satisfied with your comment, my satisfaction isn't what's at issue here. You are still ignoring the fact that some subwoofers are simply designed to play in/sound better in ported applications. Read up on Theil/Small parameters for speakers, they can/do indicate this.

This I understand very well. The 8mm sub that I have is such a sub, made for sealed applications, as well as the ED O. On the other end of the scale would be those that are designed for ported boxes. But in general, again, most subs in the market are made for dual purposes.

As for excursion, again it lends benefits to SQ in the propler design. I guess you missed those points I specified above? I wont re-write them. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif Why you quoted bass outlaw I do not know, his quote is quite misleading, if not outright wrong. From the best I can gather from his poor writing in that particular post, he seems to be saying a sealed enclosure will destroy low excursion subs because sealed enclosures 'bottom out' easily. Did I decipher it correctly? If so, its non-sense. Sealed enclosures dont necessarily bottom out subs easier, again depends on the enclosure in question. And, you can run either low excursion or high excursion subs in a sealed enclosure just fine. Cone excursion is not the determining factor in the type enclosure to use.

Er, maybe you didn't interpret what I was saying correct. That WAS my point, talking about high excursion or low. I didn't agree with what he said. If anything, I would GENERALIZE that it would take more power to bottom out a sub in sealed than it would in a ported box (both within mftr recommended sizes)

Hmm, think I used the word generalise too often. (and excuse the S and Z, I'm used to using the british way of spelling things)

My def of generalise : Cone Area X xmax = SPL

Yes, there are so many variables to upset this equation, but for most, it will suffice. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif