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Discussion Starter #1
hello everyone, new to the forum, amazing place. A week ago i had the idea of buying a new subwoofer, and this week i am in to my first build. I did my research first, and will be using a behringer ep 2500 to power my titanic in a 13 ish foot ported enclosure. I perhaps made my enclosure too soon before I did all my research but hopefully you guys can help me out.

I built a 30 inch cube, which limits my port length, according to winisd i will be struggling to get a real low tune before I hit my xmax or start having port noise, because I cannot have a really long port or can i snake it? I would really like to tune lower than 18 hz but i am entertaining ideas. Dont really have any good pictures of my adventures but Ill post what I have anyway. I built a 3.5 inch sealed box earlier in the week just to make sure I had the woodworking skills to take it a little further.
 

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Sounds like a cool project! Just some thoughts...make sure you've got some good bracing going on in your box. Once you accound for driver, bracing volume start plugging in some numbers for ports. You have plenty of room in there for some pretty large ports. Use slow elbows to make 90s if need be, thats what I did. My project is the thread below yours. Its a smaller box and I'm using the RSS390HO driver but you get the idea.
Edit: Remember to account for your port volume in your calculations.
 

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Discussion Starter #4
Amp will be a behringer 2500. I did the modeling with a 12 and some change enclosure to account for ports and driver volume. I figured I could always add in more bracing if I needed to decrease the volume and I was anxious to start the build. I'm worried now that if I need to buy a port I will be waiting for shipping so it looks like a slot port may be in order. Now I'm just looking for advice from all of you seasoned veterans.
 

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Discussion Starter #5
Woodhammer, I just checked out you build, that was exactly what I was looking for. Suprised I didn't come across it while researching. So basically I will be fine using some pvc with soft 90 degree bends to get my length. What did you do to flare the other ends of the pvc or does it really matter that much?
 

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To create a flair on the inside ends I built it a kind of donut shape into the top of the ports.... I wish I would have taken a picture. I routed out a space for the PVC to fit into over the top and them used a round over bit to create a flair. I found this image on a Google search...kind of like this.

I left one side of the "donut" flat and long enough to be glued to the box structure.
 

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Discussion Starter #7
Gotcha makes sense, I actually have some pcv lying around so now I just need to get some 90 degree turns and and learn how to use my router. When I get home I will run some numbers in winisd to determine my port sizes and tune, ill post what I find out. Thanks for the help.
 

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Well a 30" cube made with 3/4 material gives you about 13.43 cu ft of space before counting for driver, bracing and ports. I'm going to guess and say .3 for the driver and 1200 cu in for bracing being conservative bring your box down in size......here this is what I came up with. Keep in mind I'm still a noob, I'm sure Mike can do better.
 

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Discussion Starter #9
yes im learning that you may be right, i was just checking with the volume calculator. I am having a hard time with winisd because i have to change something every time the port size changes the volume of the enclosure changes... lemme check out what you have worked up.
 

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Without accounting for the sub volume and bracing I am with your ports down to 12.7 cubic feet. Your port air speed and excursion look nice too. Im gonna see how bracing affects everything and play around with the different ports, 3 ports seems like a lot of work but if its the most effective way then that what I will do. Thanks again for your help. Also should I put in higher watts since im using a behringer 2500?
 

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I tired to tune it to about 16hz maybe that's a little off....not sure. I've never worked with a Titanic before.
I see your in Richmond...I used to hang out down there with some friends. I'm just over in MD.

It is a lot of ports. You might want to look at doing some type of slot port. Maybe that would be less time in wood work. Again, that's something I've never done. I don't know what it is...I just like doing ports....maybe I should have been a plumber LOL.
 

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Discussion Starter #13
How do I account for the 90 degree bends in the pvc? What does that add to the volume of the vent? I think I'm in order to finish up. 10 feet of 4 inch pvc and 3 90 degree bends. Just need to account for the 90's. Tuned to 15 hz, I need 3, 4 inch x 34.9 inch vents.
 

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The internal 4" should be the same. I measured the center path of the elbo to get your length...google image search.

I'll have to look at my notes from my box when I get home I don't remember off hand the length of the ones I used. Being plumbing is pretty standard it would have to be close.

Edit: Just remember the end of the port inside the box should be no closer than the width of the pvc. So in your case 4" from any parallel facing walls. If you look at my build mine is about 4.5" from the wall of the cabinet.
 

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Discussion Starter #16
ok great, i think im ready to make my cuts, after playing with the router i realized i dont know how to make a small circle accurately, the router bottom is in the way of the pivot point i would need to make to make the four inch circle. tried a small hole saw/drill but it was too small. any ideas?
 

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ok great, i think im ready to make my cuts, after playing with the router i realized i dont know how to make a small circle accurately, the router bottom is in the way of the pivot point i would need to make to make the four inch circle. tried a small hole saw/drill but it was too small. any ideas?
I can tell you what I did, but I'm not sure I should recommend it.

The base of my router actually has quite a few holes in it that I've drilled for the pivot pin...which is really just a drill bit, as I've lost the original. I figured out which hole I needed and drilled through the hole in the jig into the aluminum base of the router to have enough depth to stick the pin into.
 

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Discussion Starter #19
DrDyna said:
I can tell you what I did, but I'm not sure I should recommend it.

The base of my router actually has quite a few holes in it that I've drilled for the pivot pin...which is really just a drill bit, as I've lost the original. I figured out which hole I needed and drilled through the hole in the jig into the aluminum base of the router to have enough depth to stick the pin into.
That's what I tried to do but its still slightly too big. I think I'm going to use the drill hole saw and sand. Pics later tonite. Thanks everyone
 
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