It is intended to be uncomplicated (even for the beginner), but genuinely helpful to anyone building a subwoofer or doudspeaker. Clean & Simple. Box-Port Design uses a single interface to generate both optimal and predicted profiles for your driver/enclosure. You need only basic T/S parameters to start designing!
If you’re interested in building a 4th order enclosure and need some help, hopefully this page is for you. I have put together a bunch of tips and how-to’s that should help you put together a 4th order enclosure. Check it out.There are 3 major steps you’ll need to do in order to design your enclosure.1. Choose a Driver(s) – This would be the subwoofer – anything from a 6.5″ to a 18″ will do. You can even go smaller or larger. The most common would probably be 8″ and 10″ subs, due to the massive enclosure size of a 4th order bandpass enclosure.
I currently have 4 10″ subs in a medium sized 4th order and it is roughly 17 cu/ft before displacements.2. Choose a location for the driver. Is it for a home or a car?
I assume most people will want it for a car, but they can be used anywhere really. Once you have a location you’ll need to measure the size of the area you’re working with. This will ultimately decide how many woofers and how large you can go.3.
Calculate total available area and choose what type of response you want. Do you want as much SPL as possible but at the same time creating a very peaky box or do you want a less peaky curve with the sacrifice of a few db? This will determine the ratio and size of your sections.To determine the internal sq/ft you simply multiply length x width x height (in inches) then divide by 1,728. If you do 20″ x 20″ x 10″ for example you have 4,000″ then divide by 1,728 and you get 2.31 cu/ft, so that would be a pretty small box.
If you have an non square area then you can break that up into 2 or 3 smaller square sections to make measuring simpler, then add the sections to get a total.If you’re not super familiar with what a 4th order is, it’s basically just a sealed box and a ported box stuck together. The woofer is sandwiched in between and all of the sound output comes from a port. The 4th order design will yield a very large peak in spl at or near the tuning frequency, the width of the peak will depend on the ratio of the box. You can try different tuning frequencies in WinIsd or any box design program to see what it does to the response curve but on average 45hz is a safe bet for tuning. It allows the box to still dip into the 20’s on the low end while still having output around 60hz up top, giving it a fairly wide pass band. You don’t have to rune a 4th order super low to get into the 25-30hz territory like you would a normal ported box. The sealed section of the 4th order determines low end output for the most part, the larger you go the lower it will usually play but the port tuning frequency plays a role as well.
If you tune higher than 45hz it will start to cut off some low end response. If you tune lower than 45hz it will then lose some upper end response.I built my most recent 4th order very large on the sealed side, 1.0 cu/ft per 10″ sub. Then about 2.5 cu/ft each ported. This gives me 4 cu/ft sealed and 10 cu/ft ported total volume, since I used 4 subs. It plays under 30hz no problem.
I went with a 2.5:1 ratio of ported to sealed which gives me a pretty good peak in output. It narrows the response a small amount but it’s not that big of a deal for me, I wanted the best output I could get with my You also need to remember to subtract the displacement of the woofers, any baffles or braces, and the port from any calculations you do.The box ratio is simply the sealed airspace vs. The ported airspace, the ported side will almost always be the same size or larger than the sealed side. If you have a 1 cu/ft sealed section and a 1 cu/ft ported section, you have a 1:1 ratio, this will yield a more flat response but with less peak spl. If you have a 1 cu/ft sealed section and a 3 cu/ft ported section you’re at a 3:1 ratio, this will result in a more peaky curve but the total spl will be higher. The average boxes you’ll see are usually 1:1 all the way up to 3:1.
You will see some competition vehicles as much as 10:1 or more though with a very high tuning, this results in what is called a burp box. It will play one frequency really loud, the rest will be lacking severely. They are usually used for competition only. I like to have low bass too, so I built mine to play from about 28-65hz.The port volume is calculated using the airspace of the ported section only. You calculate it the same way you do for a normal ported box. I use WinIsd to input my preferred response and tuning frequency with my given airspace and see if I can make that port length work. You want to make sure you have enough port surface area though, so you multiply the length times the width of the port, for example a 12″ x 12″ port would be 144 sq/in.
If you have 4 10″ subs which are about 300 sq/in of cone area (cone area chart at the bottom of the post) that port would be good sized since 144 is about half of 300. You can also divide the sq/in of port, 144sq/in in our example by the ported section of the box, we’ll use 10 cu/ft as an example. This gives us 14.4 sq/in of port per cu/ft of ported airspace.
This is good enough. I try to shoot for 10-20 sq/in of port per cu/ft. If you go lower you may have port noise but if you’re limited you can try it, sometimes it works.
You want to keep the port as close to square as possible, you don’t want a 15″ x 1″ port, it is too long and narrow with too much port velocity. If you do a rectangle port just make sure you’ve got a good amount of port width vs. Port height.You’ll see many people fire the woofers into the sealed section of the enclosure, I did this as well. In my case and the same as many others it is done so you can smell the voice coils if you begin the over heat them. I have gotten mine hot a few times and had to turn it down, if I hadn’t had them mounted this way, I probably wouldn’t have known it and fried a woofer.In the construction aspect of the box you’re basically just building a large ported enclosure. The only difference being that the woofers are mounted inside of the box.
You can do it in any fashion you want really, I built mine pretty simply as you can see below. You can build yours in any shape but squares/rectangles are easier to calculate, so keep that in mind.Sealed section on the left and ported on the right. You have to make sure the woofers are all connected right or make one of the panels removable. I sealed the entire box up after mounting/connecting the woofers, so if something ever blows it will have to be cut open. I did test it all before sealing it up though, make sure you do the same unless you have a removable panel.You’ll see some people put plexiglass/acrylic panels in, if I had the budget for that I might have done it. This allows you to access the woofers and looks cool.
I did not brace my box much aside from the center panel. It is 2 sheets of 3/4″ MDF where the woofers mount. So that is a 1.5″ baffle in the box, it made it pretty solid. If I had massive power and stronger woofers I probably would have but for this setup I didn’t deem it necessary. You can also coat the box in fiberglass and resin for strength. Wooden dowels do not take up much air space but add a good amount of rigidity if mounted properly and glued or better yet fiberglass them in place.I bolted my port in place, I could have probably used screws but I was originally going to make it removable. That plan changes though so it ended up being bolted in place.
I sanded the edges of the port to round it over a small amount but a router would have been better. You can also kerf the edges but this is even more work, a lot of work. It can result in a small spl gain though, so if you have the tools and time it can be worth it. If you do kerf the port or round it over with a router you need to account for that in the length.
The length will be measured from the half way point of the kerf or roundover. This usually adds only a small amount of length (1/2″ or so) but it will change the tuning frequency slightly (it will be slightly higher) if you do not account for it.Hopefully this page has helped you on your quest to build a 4th order bandpass enclosure. If I missed anything or you have any questions feel free to drop a comment below.Subwoofer Cone Area Chart (You can subtract a few percent for the surround, larger width surrounds taking up more cone area than smaller ones)Single Sub. One 5.5″ = 24. One 6.5″ = 33. One 7″ = 38. One 8″ = 50.27.
One 10″ = 78.54. One 12″ = 113.1. One 15″ = 176.71.
One 18″ = 254.47Pairs. Two 8″ = 100.53. Two 10″ = 157.08. Two 12″ = 226.19.
Two 15″ = 353.43. Two 18″ = 508.94If you’ve got 4 woofers just double the amount listed under pair and so on for more.
You can make it any ratio. The general rule is that 3:1 ported to sealed will give a nice bump at tuning frequency. The lower you go, the less of a bump. If you go 1:1 it won’t have nearly the peak, it can still sound fine but won’t be much louder in SPL than a proper ported box in many cases.
2:1 is the minimum I’d bother with myself.As for your box, I think I get what you are asking. If you have 2 subs that need 1 cu/ft total space sealed, you’d do 2 cu/ft ported for a 2:1 box. This is after port and woofer displacement, in a smaller box it is critical to account for it. If each sub needs 1 cu/ft sealed then just double the above. 2 cu/ft sealed section with a 4 cu/ft ported section, again only if each sub needed 1 cu/ft sealed.
I would go a little smaller sealed, you shouldn’t need more than 1.25 – 1.5 for a single 12 on the sealed side. You could leave the ported side big and get a massive output bump at tuning frequency. Port location will depend how your box fits in with the vehicles interior. You want it to fire cleanly and not directly into a wall. As for the port size it is easy, you just use the 5 cu/ft side of the ported box and tune it like one. A square port in a 4.75 cu/ft box (taking away woofer displacement) at 8 x 8 inches would need to be about 11.33″ long to be tuned to 45hz. That is what the average 4th order is tuned to, it will still get low.
Those subs have a qts of.43 according to this –That isn’t 100% ideal for a 4th order, the general rule of thumb is that you want a Qts of.50 or higher when considering a 4th order for subs. They would probably work but might not perform quite as well as some other subs. You could also try changing the tuning frequency of your current box along with the air space, which would be a lot less work. That might get you a few more DB on the meter depending how well it is tuned right now.
You could also try more power, an 800a2 is only giving each sub about 100 watts and per the link above they can take double that. Doubling the power should add about 3db if the electrical can keep up. If you want a 4th order though for that peak output, I’d for with about 5.2 cu/ft sealed and 15.6 cu/ft ported. This would be a 3:1 ratio, giving a nice bump at tuning frequency which I’d suggest 45hz. Well, I’m not sure if this is good or bad news but I’d just suggest a normal ported box for that sub. If you want to build a 4th order you can but the specs I am getting just aren’t great. I can’t get the port big enough in surface area to be adequate without it being crazy long which won’t fit in that airspace.
The best I can come up with is as follows.2:1 Ratio 4th order1cu/ft sealed and 2 cu/ft ported. Tuned to 45 hertz via a 4″ x 4″ square port which will be 18″ long. The port is on the small side so make sure to round the edges off to avoid noise as much as possible.The response is a few db higher from 35-60 hz over the ported box but that is higher bass notes. If you want more low end db you are better off with a large ported box for this sub. A 2.2 cu/ft box tuned to 30hz will yield more db from 23-34hz, which is the bulk of most “low bass” notes.
That is a fairly large ported enclosure so the power handling will drop a bit but it will be crazy efficient even with low power. Good luck in whatever you decide to do. I’ve uploaded the which also compares a 1 cu/ft sealed box for that woofer.Also you gave me the wrong VAS, you added a zero. Luckily I caught it because the number seemed really off. I got the right one from Polk’s website. I left out a single digit in the past and ended up with a box tuned WAY off.
Always triple check those numbers. That might not be enough space, from my quick math you’re looking at about 20cu/ft internal space. Take out the space for bracing, a large port, and the woofers and you are down to somewhere in the 15-17cu/ft area to work with. If you have 1.25 cu/ft for each woofer sealed that takes up 5 cu/ft. This leaves you about 10 cu/ft of ported space, so the max ratio you’d be able to do is 2:1 which isn’t going to give the massive bump that a 3:1 or 4:1 4th order would give. You could still build it this way but if you are going for max spl it might not be ideal.
You could lower the sealed volume some and end up with a 3:1 but this will sacrifice some low end response. I’ll throw the T/S parameters from the website into a program later on and see what it shows, then I will edit this post.
You might be best with a large ported box since you want 4 woofers in that space but we’ll have to see what the program says. Ok so I thought I had my box figured but I am once again stumped. I know all the equations and can get my box the right cubes to fit my space I am just missing one variable. My box is for two 15″s. It will be two ported chambers in the back (or ends) sharing one sealed chamber in the front center. The drivers will be facing the ported chambers. My speakers call for 2.5 cubes per for sealed box and 3.5 cubes per for ported box.
Seeing as I am going for the most well rounded sound profile I am fine with the 5 cubes (2.5 per) on the sealed side since the sub backs face the sealed side as manufacturers specs. I just have no clue what ratio I should use to figure ported sides since the drivers are facing the ported chambers. I have a pair of cheap 12″ eBay knock offs that I bought for a bit of nothing. I have zero t/s specs on this speaker. How can I determine if this will work in a 4th order box.
Win isd gives me a grim outlook if I plug in numbers from other low quality speakers. Some boxes for a single 12 figure to be over 30 cu ft!!
I can come up with approx 1.3 cu ft sealed and 3.1 ported in the space I want to use. I hope to use 3″ round ports. I have about 20 ft of heavy tube I can use in my boxes. It is pretty hard to say or guess. You can buy a meter from partsexpress and it can measure the T/S parameters for you. If you only have 1.3cu/ft sealed and 3.1cu/ft ported total space there is no way that will work for a pair of 12’s in the 4th order. I would suggest at least 1-1.5cu/ft sealed and 3-4.5cu/ft ported per sub for an average 12″ that will work in a 4th order.
So at minimum like 2cu/ft sealed and 6cu/ft ported plus you need to account for bracing, woofer and port displacement. So the box will be even bigger than that. You could try making a box for a single one of those 12’s and see how it is but plotting it will be impossible without t/s parameters. My apologies, a single 12 is what I planned to use in this space. In reference to port tuning, is it plausible to slide a port in and out while playing a frequency sweep to tune it. I am imagining that I would need to choose a port size, try it, then change to a different length, then yet again a different length.etc, etc. It seems to me that if I were to take a 8″ long 3″ round port and adjust the depth in and out, it would not change because the tube never actually changes.
Is that correct? I have a good kicker that I finally took the time to repair. I believe that is what I will use this first time. I have made small bandpass boxes for 6.5″ woofers. When done correctly, and the cabin gain of a hatchback factors in, they get relatively good response in the 38-80 range.Thanks. You are correct, you’d need to change the length of the port to have a different tuning frequency. Sliding it in and out will change it a little because having it outside the box will change the displacement in the box some.
However it won’t be a major effect. I would say a range of Mid 30’s to Mid 80’s should be achievable with a 6.5″ with a bit of experimenting. I’d try to start with 45-50hz as a benchmark and see where that gets you. It will peak here but should have decent output on each side of the curve to a certain point where it will fall off hard due to how 4th orders function.
I am running into an issue. WinISD is telling me to put the ports in the smaller of the two spaces.
If I read your post correctly, your optimum ratio is 3:1. I understood that to be 1 sealed and 3 ported. I am using a kicker 05C124 comp 12.
I am also wondering how much surface area difference there is when comparing the front and back of the cones. It has to be somewhat different. Is it simply not enough to be concerned about? One more thing. If I mount the sub facing the sealed box, am I supposed to reverse the phase? WinISD will default the box to be a flat response, a lot of time that will end up with the box being oddly sized. Just adjust the size of the ported section so it’s the bigger one.
I use the older WinISD, the newer one does not work well for 4th orders from what I tried/read. 3:1 is a pretty good ratio and a good starting point. Some people go lower for a more flat response such as 2:1 and some go as high as 10:1 for a crazy peaky output. I never even enter cone displacement, it shouldn’t have much affect on it either way. You don’t need to adjust polarity either way, some will try both ways as sometimes one will yield slightly better output but it depends on so many factors.
The times it really counts are when you have multiple woofers mounted differently – some normal and some inverted. With a single woofer it isn’t as crucial. I had mine wired normally.
You would be better with 4 12’s. The 15’s would require a lot of space and with the limited height it just isn’t worth the trouble in that space but it could be done at like a 2:1 ratio box, maybe 2.5:1. 8-10 sealed, 16-22 ported cu/ft.
The 4 12’s will work better, you have like 35 cu/ft or more of usable space from my estimates. I grabbed some random L712 t/s parameters, looks like about 6.5 cu/ft sealed, 19.5 cu/ft ported will work. That is a 3:1 ratio with a nice bump over a standard ported box from 28-61hz peaking around 43.
That would be a 30 x 10 x 5.43″ port at 45 hertz. So 300″ of port area. All measurements internal btw.
Add for bracing, port displacement, etc. Wood thickness. K so i downloaded the beta and pro. Pro actually gave me something useable but first time using this program.
Here is wat it gave me it just dont sound right from wat im seeing. Told me that optimal was 8.414 sealed and 29.58 ported was optimal which is fine i can make that work its a 3.5 to 1 ratio but told me to tune it to 32 hz which peaks at 31 hz and f3 is at 20 hz and it says for a square port that it should only b 4×4 and 1.68inches deep which sounds like a tiny port from wat u told me earlier and wat i have seen of these kinda boxes they have huge ports. Am i doing something wrong or is this info correct?. You have to adjust the parameters it first shows you. That is just a baseline.
You need to input the box size you are shooting for then check out the graph. It helps to open 3-5 different boxes so you can compare the curves as you make changes. You also need to manually adjust part of the port size. It defaults to 4×4 or whatever it is on each new box. It will not be ideal.
You would want to start around 5 cu/ft sealed and 15 cu/ft ported as a 3:1 ratio baseline for a pair of 15’s in a 4th order. The port should be around 200 cu/in baseline – so 20″ x 10″ and see if the length is doable.
I’ve read alot of the comments and questions on the 4th order box can’t believe how much space some guy’s are willing to give up for the box, like the one with 8x10s holy crap if you went 3:1 you’d be 8cf sealed sections & like 30cf ported sections. (I think, I’m new at this) That’s a whole Lotta space not to mention the extra weight 3/4 mdf isn’t the lightest wood, I guess you gotta be really hardcore to give up that kinda space for your bass.I may attempt one of these 4th orders for my 2 12 budget Infinitys I know my amps good enough as I recently blew my American Bass 10″Sub, it’s a Powerbass 2000.1d so at 2 ohms it’s rated for 1000watts (I think & 2000watts @1ohm) I just don’t have a ton of space to sacrifice. See what happens I guess it may be worth a try, thanks for all the calculations that was my issue. Hello I need Help please. I have a jl audio 13w7AE and I contacted jl audio, so their recommendations for a 4th order is 0.90 cuft. Sealed, 1.45 ported, area of port opening 50 square inches, effective port length 21.75 inches. Tuning 58 hz.
The qts of this sub is.44. While this enclosure type is not the first choice recommended by jl audio, will this still sound good. I’m looking for a 50/50 sq/sql setup. Do bandpass boxes require the same amount of power as a sealed enclosure? Thanks for any help you can provide. You are really best downloading d and trying out some boxes for yourself, just add your sub to the database and make some boxes.
You didn’t say is the vas was L or Cu/ft, I assume Cu/ft. I did some boxes and it’s gonna be real hard to tune to 73hz without having too much port.
This is still too much but a box for those @ 70hz is as follows.4cu/ft sealed and 20cu/ft ported 5:1 ratio. You need to account for sub and port displacement too. Port would be 25″ x 35″ internally with a length of 1.63″. So it will be VERY short. This box also has NO low end at all.
Strictly a high frequency burp box.Good luck. You are really best downloading d and trying out some boxes for yourself, just add your sub to the database and make some boxes. You just need to input the Qes, Qts, Vas, FS, and SPL to get a proper plot line in the program. A good base line for a 15 is around 1.5 – 2 cu/ft sealed and 3-6 cu/ft ported.
The response you want will be really tough though, low 20’s to 60 is a stretch for a 4th order. I mean it might hit all those notes but the lows and higher end will be significantly less db than the middle. Hello,To start off, Great article. We grew up making 4 order boxes but never really pay to much attention to port sizes. Now as an adult i stubbled across a 10″ FR HX2 RFD2210 for dirt cheap and thought what the heck. Have to admit its recharged my inter bass fever.
I Picked up a kenwood-9102d in the deal as well so i am hoping this amp will fit this subs needs.With my available space where i want to install the box I am thinking the 2/1 ratio is my best bet. I want to build it in a long rectangle shape with.75 sealed and 1.5 ported.My question to you is, after reading your post, it appears my port size 3″ but you stated “make sure you’ve got a good amount of port width vs. Port height.”What should be the depth in inches and the size of the port opening. Also what difference would it make if i made it rectangle instead of square?Also, i would prefer to put the port firing out the side of the ported side instead of the end.
Will that make the difference?Your insight would help me out greatly.Thank you for your post. It has fueled my drive to see what i can get out of this hefty little sub.Eli. If you use a round port you don’t need to worry about width/height. Port shape isn’t critical, some designs are just easier to fit in certain boxes.
Just make sure to round the edges and keep turbulence to a minimum. You’d need to get the T/S parameters of your woofer and use to design a box. You just create your woofer in the database.
It will tell you what size your port needs to be based on the box size and tuning you choose. You can fire the port any direction really, just keep the woofer as far from it as you can. You don’t want it right next to the port.
You box size is a good start for a 10″, you can open up 2-3 different boxes in the program and compare to curves also. Hi, I’ve been using Winisd for a few days trying to come up with the best 4th order enclosure for 2 RE Audio SEX10d4 subs. I have gotten what looks like a good response from inputting 1.3 cu ft for the sealed and 2.3 cu ft for the ported.
My question to you is when looking at the graph do I measure the response -3db to -3db or from what’s at 0db mark low to high. I plan to use a 6 inch round aeroport with some of it outside the box and pointing up through the factory sub location so I can get all the output into the cabin thanks for any advice you can give. Im about to build a 4th for 12 fi sp4 15’s with 6 cresendo bc5500, one per pair, I planned on going 24ft3 sealed(2cubes per) and 48ft3 ported tuned at 45 hz. I love the lows and i like them loud. Does this sound like a good idea going 2cubes per sub? Or would you go higher?
Also what would you recommend as to the ports square inches per cube on the ported side, should i go around 14 0r 20 per cube, bigger or smaller?And my last question would I be better off building all the subs on one wall(like yours so youd see them all when you look in) or separating them with 6 on the left and 6 on the right or a horizontal v? I do plan on keeping the shape of the port as square as possible. THANKS FOR YOUR HELP.SP415DUAL 1Fs: 27.6 HzRe: 0.65 Ohms/coilQms: 6.56Qes:.52Qts:.48Mms: 434gCms: 0.77mm/NSd: 810cm^2Vas: 70.4 lSpl: 86.4dB 1W/1mBl: 13.7 N/AXmax: 33mmRms: 3000WSealed box: 2-3.5cuftPorted box: 3-5cuftMounting depth: 11.250”Displacement: 0.21cuft. That box sounds great. I would go with that, it should get down.
As for the subs, a lot of times for me I just build what I can fit. Once you mock it up, you might be stuck one way. If you do a V, try to keep the woofers as far apart as you can.
It is possible to get a gain when you do a V, but it’s a lot of complicated math. It’s best to just go for it if that is all you can do. If not I do flat for simplicity sake. I would stick to around 15 per cube on the port myself, I think you’ll end up with a truck sized port otherwise. If I missed anything let me know.
I’m building a 4th order for a SSA xcon 15″. Should I 1:1 or 2:1 for SQL setup. Would be running 1500w daily and 2000w for bragging rights.Amp AQ 2200Sub xcon 15″ 1750w rmsSpace is 5-6 cubic ft availableI’m building a 4th order for a SSA xcon 15″. Should I 1:1 or 2:1 for SQL setup. Would be running 1500w daily and 2000w for bragging rights.Amp AQ 2200Sub xcon 15″ 1750w rmsSpace is 5-6 cubic ft availableMax specs. W40″ X h24″ X d34″Enclosure Recommendations:Sealed: 2.0 – 2.25 cu.ft.Sealed: 2.75 – 3.0 cu.ft.
OptimalPorted: 3.0 – 3.25 cu.ft. @ 26-33 hzPorted: 4.0 cu.ft. @ 26-33hz opt.Sub Outside Dia.: 15.625”Cut Inside Dia.: 14.125”Displacement: 0.20 cu.ft.T/S Specs:Re: 3.7Fs: 31.3Qms: 6.11Qes:.45Qts:.42Mms: 268gVas: 88.4 LSd: 810BL: 20.71SPL: 89.6 1w/1mXmax: 31mm. I have see a few different 4th order designs.
Some like yours and some that have two sealed chambers on each side of the box sharing the same ported area. How does this effect performance and sound?Also what causes some designs to be more sensitive and “unload” the subs when someone opens the doors to the car while playing?Last, I wanted a 4th order for 2 15’s Sp4’s.
I want to play lowww like in the 20’s. Don’t really care much about the higher notes some maybe 3.5:1?? And will a bigger port area cause more air movement?Fs: 27.6 HzRe: 0.65 Ohms/coilQms: 6.56Qes:.52Qts:.48Mms: 434gCms: 0.77mm/NSd: 810cm^2Vas: 70.4 lSpl: 86.4dB 1W/1mBl: 13.7 N/AXmax: 33mmRms: 3000W. Hello, I’m looking for some basic specs on a 4th order bandpass box for 1 Sundown Audio Ev12 (Fs: 35.8 hz Qes: 0.56 Qms: 6.79 Qts: 0.52 Le: 1.85mH Vas: 47.6L) I am looking to bulid a 2.5:1 ratio enclosure for the trunk of a Lexus IS250.
Could you recommend Air Space and Port size (square port). I am considering making the rear chamber.75-1.0 cu ft and the front chamber 2.0 -2.5 cu ft. As for the port I’m really not sure, was thinking maybe a 4″ or 5″ by 8″ diameter. Length is the big question. Any help would be much appreciated. Hi I am plannig on doing this box.
I have 4 kicker 12″ CVR dual 4 ohm vc.what would my box need to be like?How do you calculate port length?I have Lincoln town car plenty of trunk space. The main opening is square.40x25x25then the upper shelf that can also be used is 40w x9t x 15d.The subs can go in one box with 4 individual chambers. That would put me at 1.38 cu ft.per sub. I would then have an Lshapped upper chamber. The front shelf area of 40x9x15=3.125 cuft. Then the top of the subs connected to the L (basically i just used measurements in nice square.) the other half would yield me 5.902 cuft.That would put me right at 9 cu ft ported above the sealed 5.52Would this work and be goodI can make the sealed camber smaller to get to the 2:1 ratio How big is the port. I want it to come right up thru my rear deckI know this was a lot.
But I hope it helps and you can help me This would be just a big L shaped box. Hello, I would like to build a bandpass box 4th order for my subwoofer Pioneer TS-W3003D4 12 inch, but have some doubts as to the subwoofer manual calls for 16 liters to the sealed compartment and 98 liters for the ported enclosure. I would appreciate your help and opinion on the measures of each compartment and the Port size (square port).Below is the subwoofer parameters Pioneer TS-W3003D4 12 inch:Fs: 35 HzFrequency response: 20 Hz to 80 HzQms: 11.50Qes: 0.62Qts: 0.59Mms: 257gVas: 34.6 litersSpl: 96dB 1W/1mXmax: 13.8mmRms: 600WThanks! I am building a 4th order thats going into the back of a 2 door Jeep cherokee. I have all the room i need up to 20+cuft.
I’m going to use 2 Soundqubed HDS15’s at 1 ohm with a AQ4500.1, Singer 320A Alt and 4 XS3400 Batts. So Beefy electrical.Parameters:F(s) 35.66 HzQ(ms) 7.836Q(es) 0.927Q(ts) 0.829Sensitivity 1W/1m 86.33 1W/1mBL 25.20Xmax 14mmRMS 1200WPeak 2400WI’m wanting a good daily pounder, something thats going to play GOOD highs and GOOD lows. I cant stand muddy bass. I’ve spent alot more on my mids and highs than my lows because i want LOUD but clean as hell.
If you can let me know what you think about the HDS15s for this. I havent purchased them yet because i need to make sure this is going to work. I already have the Alt, Batts and SQ4500.1 though.Thanks, Jack. This is the woofer & i will be using the two of them, can admin please help me out with the dimensions for a 4th order bandpass.NVX VC-Series Subwoofer Specifications:15″ Dual 2-ohm VC-Series Car SubwooferPower Handling:RMS Power Range: 850-1000 wattsImpedance: Dual 2 ohmsPressed paper cone with woven fiber topHigh excursion foam surroundCast aluminum basket for maximum rigidityDual Poly-Cotton Spiders3″ Aluminum Voice coil195oz. Triple stacked Ferite magnet motor structure with protective rubber bootSensitivity: 87dBFrequency response: 20-220 HzResonance Frequency (Fs): 24 HzTotal Speaker Q Value (Qts): 0.36Electrical Q Value (Qes): 0.409Electrical Resistance of Voice Coil (Re): 3.20 ohmsMechanical Q Value (Qms): 2.910Optimal sealed box volume: 1.50 cubic feet tuned at 40 HzOptimal ported box volume: 2.50 cubic feet tuned at 33 HzTop-mount depth: 7-9/16″.
Hey, should the tuning frequency be determined by the cars resonant frequency? Or does that not matter? I was told my car has a 55hz resonant freq so the 4th tuning should be a few hz below that – 52hz. Is this true?
Or should I still stick with 45hz as my tuning frequency? Also if I do 52hz what bandwidth range would I be hitting?Secondly, the port direction. If the port is facing up thru the rear deck vs forward thru the hole when the seats are down. Will this result in a different sound or will it sound relatively the same? If it won’t sound the same what difference would I hear vs port aiming top to port aiming forward??Finally, I was told 4ths are not musical at all and mainly used for spl purposes and don’t make music sound good for everyday listening, is this true? If so, how do u make it more musical but loud at the same time?
Also – I was told 4ths don’t work well in coupes but better in sUvs and trucks and sedans. Is this true as well??Thanks for your help. You can tune to the resonant frequency to get the peak DB but you will lose a lot of low end tuning that high. Unless you plan to compete I would stick to the 42-47 range. The direction the port fires can affect sound but it isn’t a huge deal. Often I do what is easiest and works the best in a given setup. Aiming it through the rear deck would likely cause more rattles too.
You can put a 4th order in anything, vehicle doesn’t matter. However they are indeed not very musical, they are extremely peaky enclosures. Some songs will have much more bass than others.
You can tune it 1:1 ratio to make it less peaky but that sort of defeats the purpose of a 4th order which is SPL. If you want clean sound that isn’t too peaky then a nicely tuned ported enclosure may be best. I need help in calculating the box. I have 2 15 sub.
Here is their descriptionRe = 3.9380 ohmsFs = 26.7755 HzZmax = 35.6960 ohmsQes = 0.5415Qms = 4.3666Qts = 0.4817Le = 5.0207 mH (at 1 kHz)Diam = 317.0000 mmSd = mm ^ 2 Vas = 4.3109 cu. FtBL = 17.78Mms = 255.7221 gCms = 138.1643 uM / NKms = 7237.7578 N / MRms = 9.8524 R mechanicalEfficiency = 0.4073%Sensitivity = 88.1168 dB @ 1W / 1mSensitivity = 91.1949 dB @ 2.83Vrms / 1mI use the WinISD program and have the following parameters: closed camera 4.6 cu.ft. Ported camera 12.7 cu.ft. And setting port 45Hz. The port sizes I use are 2 10 inch tubing, their length is 8 inches.All is well or that it should be changed? I want to have more volume at 28-35HzWith patience to wait for your answer.