Can I port my sealed box

[KAiRO]

Is it ok to do this? Where is the best place to put the hole, and how big should it be? I'm a little wary of cutting a hole to just try it out for obvious reasons .

 

[XplorerKid]

from what i here.. a ported box has to be bigger than a regualr sealed box... so you would prolly need to build a new box

PEACE

 

[Redrig]

I think he right, ive never seen a ported box as small as a sealed box. You can get a ported box pretty cheap off ebay.

 

[Nicaraguense]

Actually

Actually you have that Bass Akwards A ported box can be smaller because it allows the thing to breathe. A sealed box has to be larger to have more air inside to make up for the fact that it can't breathe. Anyways, I prefer a sealed box because it actually puts out lower bass than a ported one. Not that the difference would probably even be audiable or anything.

 

[XplorerKid]

i was only going by what i was told from Expo5.0

ported boxes by nature have to be larger

PEACE

 

[Nicaraguense]

Hey I could be wrong

I might have it sdrawkab myself

 

[Redrig]

Like i said ive never seen a sealed box bigger than a ported box, unless custom built. But i dont know.

 

[KAiRO]

I was under the impression that the ported box put out a lower resonating bass. . . not sure though. That's what i'm going for. If it means buying another box, that's ok then. I built my last one (before my current one) and it didn't sound too great.

 

[mhn3773]

ported boxs on a scale from 1-10 are about an 11 on the diy scale...much much harder to build and the error % on a ported is almost nill..if u get a sealed box "close" it will sound fine u probably wont even know..but if u build a ported box to "close nuff" specs it will probably sound like garbage and could even hurt the sub because the power handaling of the sub will be waaaay down

that said if u wanted to port a sealed box ud have to really modify the box...probably make it bigger so it wouldnt be the same box anymore and to much work

ur probably better off keeping ur sealed box and start building a ported..that way if the ported doesnt come out to be perfect u can still fall back on the trusty sealed..drew can probably tell u more or typhoon

 

[KAiRO]

What I'd really like to do is get one 15 and put it in a bandpass box and put my current system in my bro's jeep as far as building my own ported box, my subs aren't worth the extra effort! maybe someday when i get decent equipment i'll do it, but for now....its not gonna happen. I will keep my eyes open for a already made ported box. I'm safe to go within +/- 20% on the volume of my subs right?

 

[mhn3773]

what do u mean 20%??

whats wrong with ur current subs? usually any sub can do good...others just do it louder and with a wider freq range..like my subs are loud but they seem to be kinda crapy on the freq scale..just cant hit the higher note..meh rattles my car back down to the hell it came from so im happy lol

 

[KAiRO]

by 20% i mean if the box is supposed to be X by Y you are safe by going X +/- 20% and Y +/- 20%.

And you like the hatch rattle??!? i like it when my trunk doesn't sound like its gonna fly off and hit the civic behind me

 

[Fixxer]

I need to deaden my hatch badly! It rattles up a storm now. My roof also buckles alot.

 

[Arnie897]

I think that sealed boxes are far superior to the ported style. I've had both and the sealed is much more accurate. I would look up what your speaker prefers at the companies website first.

 

[410Fortune]

It depends on the speaker.

Rule of thumb answer is NO
When designing the box to begin with the speaker parameters were taken into account, all the dimensions are very critical to get the right sound and frequency extension from your Sub.

Simply porting a sealed box will hurt the speakers performance, a ported or vented enclosure will need to be designed from the ground up, all over again.

When deciding whether you want the sound of a sealed enclosure or the low extension a vented enclosure provides you need to consider the speakers environment. IN a truck,car, SUV I prefer a sealed enclosure EVERY TIME. SEALED gives the punchy sounds a sub shoudl provide, without CHEATING like a vented enclosure does.
However in a Boat or large room (house) a vented enclosure kicks ass because you want more low end bass to fill the room, or lack of room in a boat.
IN a car or truck you basically have a small room to fill, and a sealed enclosure is much much better ffor sound quality.

Now most speakers performokay in both enclosures, but many speakers these days are designed to be used in a specific enclosure, so it depends on your speaker.

Sealed is better

 

[mhn3773]

i dont drive an ex ..long story..but my trucklet doesnt have a hatch to rattle..it has a removable top that rattles like theres no tommorow so i just take that off i havent decided if i want to spend the time on this car to fix the rattles since i may not have it much longer

"sealed is better" only if thats the kind of soud u want sry its just thats the same crap bestbuy and those people say because thats what they have been told..it depends on what kind of bass u want and what subs u are working with..my sub i didnt think they were gunna be as clear as they are so i wanted a sealed box to make up for the SQ..but a ported would have givin me more brutal bass

in like drews car his 9500s are already butalizingly loud so sealed was the way to go for him he gets the sharp response and small enclosure of a sealed box with massive bass because of his subs...

if u want to compete in an SPL comp then ur gunna lean 9 outa 10 times towards a ported box..but u are also getting an spl sub which chances are will have little to no SQ i.e. kicker soloX runs at 40% distortion when u push it great for spl..now for eric clapton

 

[Fixxer]

Depends on what the port is tuned at. The lower the tuning the more SQ, the higher the tuning the more SPL and worse it sounds. If your sub has a low FS and your port is tuned low (around 26hz) then its not that much worse then a sealed enclosure.

 

[janikphoto]

a lot of talk going on here, but no one mentioned building a transmission line box yet... Just joking because you'd probably need to build a weird-looking contraption that would fill up the back of any suv or truck bed if you were using 15's, but it's the same technology that the bose wave radio employs.

The theory is similar to a ported box in that it takes the rear soundwave and adds it to the forward soundwave, giving you extra loud bass. The ported box gives you more spl, but only at a certain frequency range in which the port is tuned for. This is why everyone is correct in that you can't just cut a couple holes in a ported box. The port must match the speaker and box size and can't just be added later. A few rules of thumb when building a ported box, though. Make the hole as big as possible, but not bigger than half the diameter of the speaker itself. So you could have a 7" port with a 15" speaker, but not really any bigger. The smaller the porthole, the more chance of port whines and whistles. Also, flair the ends of the ports, because the sound will react better to a rounded edge than just a squared edge. Kinda the same theory as a trumpet or other horned instrument.

Now, when making the port, you also have to consider length of the port, which is directly related to several perameters that you can usually get from the speaker manufacturer. You can't just decide to make the port diameter just under half the speaker diameter and then pick any port length at random. I'd go into the exact calculations, but I'd have to look them back up, since I haven't built a ported box in about 4 years. They are just too much effort. They are REAL picky...

Oh, and if you are off on the port dimensions, it will affect the frequency at which the port adds extra spl, so you can wind up destroying your woofer if the frequency is too high, because any notes played below the port's tuned frequency will just be 'dumped out' so to speak. Your woofer will act like it's not in a box at all and the further it gets below that tuned frequency, the worse it gets. Also, if it is tuned too low, the port will be wasted because it is tuned to play frequencies that aren't in the music or are too low for the speaker to produce to begin with. This just basically wastes all the pros of having the ported box and just leaves the cons.

And you can easily be way off with your frequency if you're not very accurate with your numbers.

So, to make a long story longer, read a book before building a ported box. Yes they have their advantages, but sealed boxes do too. I prefer a sealed box that is on the big side because you get nice deep bass and a good woofer will still have a decent punch in the higher range. It makes for a very good real-world listening experience...

 

[Fixxer]

Originally posted by janikphoto
Oh, and if you are off on the port dimensions, it will affect the frequency at which the port adds extra spl, so you can wind up destroying your woofer if the frequency is too high, because any notes played below the port's tuned frequency will just be 'dumped out' so to speak. Your woofer will act like it's not in a box at all and the further it gets below that tuned frequency, the worse it gets. Also, if it is tuned too low, the port will be wasted because it is tuned to play frequencies that aren't in the music or are too low for the speaker to produce to begin with.

It is wise to get a amp with a subsonic filter if your tuned high, not so important if your tuned low, or have a sub with a progressive spider and high xmax.

 

[janikphoto]

Yeah, my audio control x-over has a subsonic filter for that very reason. And your sub with good spider and xmax comment supports what a few others have said about getting a woofer specifically designed for a ported box and not just throwing any old speaker in there.

Old cerwin vega woofers were specifically designed for ported boxes and they came with very specific dimensions for building the box. Usually the sheet that comes with any woofer is very accurate and worth following. A company will usually test a woofer to find the best box parameters, so you don't have to guess...

We (stereo shop I used to sell at) also had an extensive support book from jl on their woofers and it told how they reacted in every size and type of box (with tons of details), so you could be sure to build it exactly how you wanted it to sound. I've been happy with every box that I've built when I've followed the manufacturer's advice...