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I have a Alpine SWR-10D2 (1000 watts rms) i'm mounting to an alpine MRX-M110 and am looking to build a box for it. I'm going for SQ so I figured a sealed box would be best, am i right?

I was told by a buddy who owns an audio shop that this sub is best in a ported box, however upon plugging all info into WinISD to tune the port correctly it's saying I would need port length over 60 inches and I'd still be pushing out over 60 ft/s air velocity.

So my questions are for best SQ, ported or sealed? if ported do i need to worry about air velocity? I am completely new at designing ported enclosures so I apologize for the dumbness going on here lol
 

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60 inches??
as far as i'm concerned every woofer works better in a ported box but i'm a ported box guy some guy's love sealed boxes it's all about what you like.
there are a few factors that determine port length.
enclosure volume(size)
tuning frequency
port size like 3in or 4in if it is going to be round or slotted???
the smaller the round port the shorter it is and the smaller the box the longer the port is going to be.
if it's round i wouldn't go less than 4in in my experience 3in sucks.
you can go here and do some calculations...
i don't know the program you working with but this link is pretty dam good for that stuff.
Car Alarm, Car Stereo, Mobile Video, and Cruise Control Info for Installers
or keep it simple go with a sealed box
 

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Discussion Starter #3
Thanks for the help, I thought of one more question, Do I run the risk of blowing my sub? The sub is rated 1000RMS and 3000peak, with the amp being 1100RMS and 1800 max.
 

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Its crazy to think that by default a sealed box will sound better than a ported box. I think the only default is that a sealed box may not do as much wrong as a badly designed ported box will. But no reason you can build a proper ported box and have it sound great in your vehicle.

60" inches should not be needed, so maybe you could tell us how you go there? And maybe someone would be able to help make that more manageable.

Also you need to filter your car audio buddy...he may be saying ported is best because its loudest. At least thats how most shops i know of qualify best:D
 

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I have converted small sealed boxes to ported enclosures with some success. I used 2 1.5" (inside diameter) PVC tubes and drilled holes in the top of the box. Where you place them makes a difference and from what I have seen it really depends on the vehicle the box will be placed in. For whatever reason this is the way that I saw recommended for sedans. It worked quite well. Had more output and I could modify the ports to tune the box as I saw fit. I was using a small box (.54cuft) and I ended up using the 2 1.5" tubes in order that I could fit them in the box. Of course to get lower tuning frequencies (below 37Hz or so) I needed elbows in there. I found out that it is important to make sure there is enough room between the port opening inside the box from any walls and the driver itself so it can take a bit of thought and finesse to design properly. From what I recall the distance from any wall or driver should be at least the diameter of the port. If you do not do this you will encounter some problems with your response and integrating the sub with your front stage.
 

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that sub wants a tiny enclosure, so the port length is going to be long. at least for a port that doesn't huff. termlab says anything between .7 and 1.1 cubes tuned to 27ish. how large can you go? doing 1.1 tuned to 26 gets you your best low end. thats a port with 15 square inches and 58.75 inches long. wrap the port around the enclosure and its manageable. is the gain worth the space? up to you, but a sealed box for it is .69 cubes. your port length will go up as your box size goes down, so a smaller box will not make a real difference in outside size. smaller box, longer port
 

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that sub wants a tiny enclosure, so the port length is going to be long. at least for a port that doesn't huff. termlab says anything between 1.1 and 1.9 cubes tuned to 27ish. how large can you go? doing 1.9 tuned to 26 gets you your best low end. thats a port with 24 square inches and 46.75 inches long. wrap the port around the enclosure and its manageable. is the gain worth the space? up to you, but a sealed box for it is 1.1 cubes.
why are we trying to tune a car sub so low?
 

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he said SQ not peak output. no info as to what car or what type of music is his preference. its easier to turn a sub down than over drive it to do what you want
 

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so the recommended specs for this sub is to have a volume of .75-1.3 cubic ft if ported along withhaving it tuned to 35-39Hz. When attempting to accomplish this in WinISD I notice that the smaller a port i put the higher air velocity, so i was thinking to keep the air velocity down and that's when the port grew in length. the dimensions I have to work with are 27 in. wide, 13 in. tall, bottom depth of 13 inches and a top depth of 9 inches. Any recommendations? I was thinking of having 2 ports symmetrical.

Also any input on my previous reply? possibility of blowing my sub with this particular amp?
 

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I'm putting it in the trunk of an RX8 and wanting to maintain a decent amount of trunk space, I primarliy listen to alt., rock, dubstep, a little country, and even less scarce is rap.
 

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Sealed Boxes are a heck of a lot easier than a Ported enclosure to screw Up. I think that's part of the reason people Gravitate to them so much. A vented enclosure can take a bit of trial and error to get right.

Anyone can plug the numbers into winSD but every cars trunk/interior/environment is different and that's not even taking into account where the enclosure is placed or firing against in the trunk/hatch.

So many things affect frequency response as we all know in a vehicle. I guess that's why people pay PWK to design their vented enclosures for there specific vehicle. This is all IMO of course.
 

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I have converted small sealed boxes to ported enclosures with some success. I used 2 1.5" (inside diameter) PVC tubes and drilled holes in the top of the box. Where you place them makes a difference and from what I have seen it really depends on the vehicle the box will be placed in. For whatever reason this is the way that I saw recommended for sedans. It worked quite well. Had more output and I could modify the ports to tune the box as I saw fit. I was using a small box (.54cuft) and I ended up using the 2 1.5" tubes in order that I could fit them in the box. Of course to get lower tuning frequencies (below 37Hz or so) I needed elbows in there. I found out that it is important to make sure there is enough room between the port opening inside the box from any walls and the driver itself so it can take a bit of thought and finesse to design properly. From what I recall the distance from any wall or driver should be at least the diameter of the port. If you do not do this you will encounter some problems with your response and integrating the sub with your front stage.
1.5 inches???were you making a flute?? LOL i have also ported a prefab sealed box or 2 with some success.
i don't know may be that worked for you.....but 1.5 is way to small.
the woofer needs enough port to breath if you snorkeling do you use a straw from mcdonalds??
i have 2 10's in 2 cubic feet i called the manufactures tech support and told them i had 1 3in port.(by the way if you do 2 ports they get longer).
they told me that "yes a 3in port don't have to be as long as a 4in but that 3in was not enough port area" the woofers needed more than a 3in.
for shits and giggles i did a 3in and then tried a 4in and i can tell you they were correct.1 of my best friends attended RTTI(rockford tech train institute)he tells me if it's a round port don't go any less than a 4in.unless you want to build a whistle.i actually use Precision Port not PVC.
WAY BETTER SOUNDING THAN PVC.
Precision Sound Products
 

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so the recommended specs for this sub is to have a volume of .75-1.3 cubic ft if ported along withhaving it tuned to 35-39Hz. When attempting to accomplish this in WinISD I notice that the smaller a port i put the higher air velocity, so i was thinking to keep the air velocity down and that's when the port grew in length. the dimensions I have to work with are 27 in. wide, 13 in. tall, bottom depth of 13 inches and a top depth of 9 inches. Any recommendations? I was thinking of having 2 ports symmetrical.

Also any input on my previous reply? possibility of blowing my sub with this particular amp?
i would not be too too concerned with having the most ideal port velocity. Its not really going to be anything audible in your trunk. Thats more of a HT thing where the sub is in the room, and you are blasting huge power and outputting extreme LF sounds. I am not a ported sub expert, so i can't say for sure what the lowest acceptable air speed should be, but goodle this site, it has been discussed.

As for tearing up your sub...you dont have to worry about that because your amp has a SSF so just set that slightly below your tuning and you should be fine.
 

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that's what i was thinking just set the SSF lower, but I was just chatting with a guy that does installs and he said I'd blow, apparently he says alpine overrated their newest type r's, but I've never heard that from anyone before so thanks for the input! So sounds like most people on here say go ported if you can do it right, however stick with sealed if you can't build a ported box?
 

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i would not be too too concerned with having the most ideal port velocity. Its not really going to be anything audible in your trunk. Thats more of a HT thing where the sub is in the room, and you are blasting huge power and outputting extreme LF sounds. I am not a ported sub expert, so i can't say for sure what the lowest acceptable air speed should be, but goodle this site, it has been discussed.

As for tearing up your sub...you dont have to worry about that because your amp has a SSF so just set that slightly below your tuning and you should be fine.
the sub should have a recommended tuning freq in the manual,rockford-35 htz,my jlw712-32 htz.the jl manual gives you a box accounting for port+woofer displacement for a slotted box.i think i'm going to pull the 10's out and try my jl.
the jl is brand new,i have never put power to it i only opened the shipping box to look at 2 years ago.:D
shit it took me 2min to find this
http://supportalpineusa.custhelp.com/ci/fattach/get/101/1424994853/redirect/1/filename/Recommended Box Designs.pdf
alpine max ported box size 1.5 cube's tune it anywhere from 32 to 37 htz gross box volume 1.71
dimensions 23x12.5x14...check the link i posted
according to http://www.the12volt.com/caraudio/boxcalcs.asp#por
you will need a 4in port about 14.9 for 35 htz. use these links...the12volt is awesome for the calculators and they have never let me down.
 

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that's what i was thinking just set the SSF lower, but I was just chatting with a guy that does installs and he said I'd blow, apparently he says alpine overrated their newest type r's, but I've never heard that from anyone before so thanks for the input! So sounds like most people on here say go ported if you can do it right, however stick with sealed if you can't build a ported box?
well you are going to protect the sub with 2 things...the SSF and more important, your ears. Start with the gain low...and raise it slowly until the low end balances with the rest of your system.
If you said you were looking for max output and loved showing off your bass, then i would say for sure go sealed to help protect the driver.:D

As for preference, sealed or ported...there is no consensus here...just build a proper box either sealed or ported and you should be happy. Its when you buy a $35 prefabbed box from walmart and drop a sub into it and crank your gain with no SSF that you then get some pushback from the anti ported crowd.
 

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1.5 inches???were you making a flute?? LOL i have also ported a prefab sealed box or 2 with some success.
i don't know may be that worked for you.....but 1.5 is way to small.
the woofer needs enough port to breath if you snorkeling do you use a straw from mcdonalds??
i have 2 10's in 2 cubic feet i called the manufactures tech support and told them i had 1 3in port.(by the way if you do 2 ports they get longer).
they told me that "yes a 3in port don't have to be as long as a 4in but that 3in was not enough port area" the woofers needed more than a 3in.
for shits and giggles i did a 3in and then tried a 4in and i can tell you they were correct.1 of my best friends attended RTTI(rockford tech train institute)he tells me if it's a round port don't go any less than a 4in.unless you want to build a whistle.i actually use Precision Port not PVC.
WAY BETTER SOUNDING THAN PVC.
Precision Sound Products
Yes, TWO 1.5 INCH DIAMETER PORTS. This was the only way that would work for my sub and the box I had according to WinISD. I noticed no port noise also.
 
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