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Discussion Starter · #1 ·
Ok, so I have decided. My first DIY sub is going to be a SONOSUB! Woot! I found a piece of 24" sonotube approximately 12' long. As much as I'd love a 12 foot sub, I doubt it would fit anywhere. I am planning on using an IXL-18mk2 with a 6" or 4" port, debating on making the sub anywhere from 2' to 6' high. I am running a Behringer Inuke 6000 DSP, and am familiar with REW. Any suggestions for this driver and a 24" tube up to 12 feet ;)

I'm wondering what ideal tuning would be, I'm in a carpeted baseent approx:14 feet by 17 feet. Also, can I use a smaller sonotube as a port, or should I try and find 6 or 8 inch pvc pipe :(

(I'm using sonotube 2.3, porkin around with numbers, but I have no clue what I'm doing, or what's best for my room)

Thanks guys!
 

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7cuft 17hz. If your sonotube is 1/4" thick walls and 24" diameter then 31" tall should do. 31" x24" is roughly 7.75cuft. Take away the driver, port volume and double baffle and you have about 7cuft. One 6" port 33" long is about .5cuft also.

1400watts to hit Xmax with a Hpass filter at 17hz and port velocity will be around 26m/s at 17hz.

BUT in saying this you can tune for anything you like. You may want a large enclosure. You may want 12hz tuning or 22hz tuning. Its up to you.

And yes you can use a sonotube for a port. Just remember to add something on the entry of the tube/port for a round over entry and exit. If you use a straight tube and no round over you will have turbulence much quicker then if you used a round over entry and exit.
 

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Discussion Starter · #3 ·
But how can the port be 33" long when the tube is only 31" high? Maybe I can seal it and skip the port? Thanks for the advice!
 

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Check out my thread for some ideas (hopefully I will put in some real work on mine this weekend while my kid's at the grandparent's house).

http://www.hometheatershack.com/forums/ported-subwoofer-build-projects/68413-si-18-sonotube.html

Use WinISD

http://www.linearteam.org/download/winisd-07x.exe

And this SonoSub designer

http://www.subwoofer-builder.com/sonosub.htm

Here's my spreadsheet I'm using to calculate everything I need to cut.

https://docs.google.com/spreadsheet/ccc?key=0AjwCXbS5q2UGdFExdkZ4NW1UTm9jZUJydHFhcW5YMnc&usp=sharing

As you can see from my SketchUp, I'm cutting some of the wood out of my plugs to minimize the overall weight. I'm emotionally scarred by the weight of my last build. :sweat:
 

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Sorry was in a rush earlier. Height of sonotube will have to be changed to allow proper port length. That being said you can bend a port to fit desired length.

The real question will be what tune do you want?

We can change any parameter as long as you know what tuning you want. Driver will most likely take about 11" away from length you can use for the port if using a single port above driver. SO 31"+ 11=42"

Many options. You just have to chose a direction. Most people are happy with a 18hz tune. Some want more down low. Some want a smaller cabinet. Choices choices.
 

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Discussion Starter · #6 ·
I would like the sub to play as low as possible without sounding like garbage? I'm not sure I understand tuning :( I just want my bones to shake ;)
 

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Discussion Starter · #7 · (Edited)
Hmm... I like the Sonosuggestions, thanks! In order to keep measurements simple, I was thinking 8" port made of sonotube (and magically flared somehow?!) with a cap to cap height of 5' and a port length of 2'6", seems this will tune to 16.8Hz based on Sonosub V2.03. Does this sound ideal? Oh man, all I dreamt about last night was subs :rubeyes:
 

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Ideal will just be what your happy with. So in regards to a 12hz-20hz tune you will be fine with the IXL 18. The lower you go the bigger it needs to be for a better response curve. Chest or bone rattling occurs more like 60hz. So if you have small L/R speakers you might not get this. A HT subwoofer tuned to 16hz and big enough size will give you the lows, such as a train going through your living room. For a more tactile feel you will have to use bigger L/R/C speakers.

BUT for now this is all about your subwoofer. If you have a sono that is 5ft long between the caps then with double baffles on both ends your looking at roughly 13cuft. Minus the port and your at about 12.5cuft. 16.8hz or 17hz tune will have an 8" port 31.49" long.

Everything appears to "fit." :T
 

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Discussion Starter · #9 ·
So if you had the option of using 5 feet or 6 feet, and had the space, which would you choose? What port length would you use with your choice? I bought the doweling (1.25in), mdf, pl premium, silicone, primer, hammered black rustoleum, and jig saw refills.

I even made an awesome 'circle maker' based on this:


I'll post lots of pics and REW graphs (when done) as I go... Is a 26" base stable enough for a massive sonosub like this?!
 

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26" base is big enough. If you want a huge sono then 6ft would be good also.Thats close to 18cuft when built. I would tune at 15hz.

Remember that with a 6ft section you have double baffle on both ends. Or more depending on what your likes are. So with double baffle that is another 3" using 3/4" MDF/PLY. Then you have the base plate for another 3/4" and then your legs. You will need at least 1" above the surrounds highest resting point. So lets add another 2" to be safe.

So thats roughly 78". And some people like to use tall legs such as 5" legs. So you could be at 80" or more when it is finally built.

I dont like tuning really low myself because you lose a lot of SPL higher up.

Here is a comparison:


This being said if your after 14hz then you can see the lower tuned design wins by a lot at that frequency.
 

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Discussion Starter · #11 ·
I'll make it 5' (plus endcaps) with a 3' port... should tune to close to 15. I have no way of flaring the sonoport though... i guess its fine, no flare. impossible to find 8" pipe lol
 

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Discussion Starter · #12 ·
I'm a bit worried about mounting the driver. I'm guessing T-nuts would be fine based on what I read, but what size for this driver? Seems they come in many different metric sizes.
 

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It's easy to do a simple flare. You just flare the wood and shunt the tube up against the top layer. Kind of hard to explain. I found this image.

http://cdn.avsforum.com/5/5a/525x525px-LL-5a8cf1b2_vbattach66774.gif

Notice the "donut" on the bottom.

Regarding bolts, I prefer hurricane nuts, especially for MDF. Getting the right bolt is a tough one. You're just going to have to measure the mounting holes in your driver and dig up the various bolt dimensions on the net. My problem is that the bolt heads would not fit through the rubber gasket so I had to spend a couple of hours cutting away rubber. Pain in the neck.
 

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Discussion Starter · #14 · (Edited)
Cut the circles with a jigsaw, that 'jig tool' in the youtube video was horridly ineffective, ended up just doing it by eye. Once cut, I used belt sander to get the major stuff, then a drum sander to finish the circle edges.



My Dad had a 'Frostner' bit set, so I picked the 1 1/4" one to go with my doweling of the same size.



We taped some graph paper together after cutting the dowelling to 7" long, and edged around my cut circles with a razor blade. WAAAY better than scissors. No my circle was not perfect, but we needed to have the dowels lkine up on both circles perfectly. We aimed for 1 1/2" away from the edges, after dividing the paper circle into 6 quadrants. at 1 1/2" on the line, we marked and circled, then hammered a punch to ensure the centre for the dowel recesses. We then had to flip the paper and repeat the punches on the other circle. When completed, we had perfectly lined up recesses. The spike in the frostner bit lined up perfectly with the punch indent :)



The base dowels fit beautifully recessed at 5/8 " depth. Even left a small dimple for pilot holes. We then screwed 1 5/8 number 8 construction screws into the base AFTER using a countersink drill bit to pilot. MDF seems to give a hard time to screw heads, will not recess without your help :(





Now I have primed the Sonotube, cut it to 5'4, used Zinser. Also removed 90% of the inner plasticky-wax stuff inside the sonotube. Cut the port to 2' 6", and was surprised that despite it being an 8" sonotube, it measured at 8.5"! Oh well, sub is now tuned for 17.5hz with everything.



Can't wait to get my driver! It's being made right now! Should also get my amp soon, so I will be very happy. I will edit this post and put up some pics if I can figure out how ;)
 

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Discussion Starter · #15 ·
Getting a bit further. First colour choice:



Then I changed my mind:

and
I used this:



Looks darker than the picture, kinda gunmetal. Sometimes brainstorming is the best way to get around a problem. Using an 8" (that actually measured 8.5", watch out) sonotube as a port was great, but I needed to figure out how to flare it... Went to my Dad's for father's day, he suggested using a pool noodle!



he cut it in half with a sharp knife. We tested a couple of 'bonders' and we decided silicone 1 should work



I clamped the cut piece of noodle and caulked it.





I then glued the port endcap with PL Premium



and primed with this:



Fit right in!




Finished the base



AND...
Finished, aside from the driver.




Now I have hit a bit of a wall... Since my circles aren't as perfect as Maynard's, do I need to caulk on the inside of the tube? There are small gaps in the endcaps, but I am not sure if they will affect sound. I was thinking I could just get away with caulking around the top endcap on the outside of the tube with black caulk, then spray painting it... This way I can always remove the top cap should I ever need to... Will this affect SQ / turbulence?

Let me know :) :help:
 

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How big are your gaps? PL will fill the gaps also.

As long as your port is smooth then the sound should not be affected. But be sure to make sure there are zero air leaks, when everything is done. Air leaks will rob you of spl and can cause you to push the driver beyond its limits without knowing.

And if your talking about the end cap being placed on the inside of the sono not being cut perfectly I would definitely use PL. When you start to push this sub the caulk is not strong enough for the long haul. It may work for a while but eventually will not hold up to the inside pressures. PL will no problem.
 

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I used wood glue, and a finish stapler. Air tight, but I don't need to consider takin it apart so ymmv! I also wrapped in carbon fiber vinyl.
The yellow sub here IS NOT the finished one above! Lol! It is a 6.5" driver I took out of an htib sub, and tuned it to around 32hz. The numbers in the book say response goes down to 30. Anyways, I did the jigsaw thing on the little one, and also have a couple 1/8 gaps, a couple inches long. It pushes air through them, and when I squeeze em down, I can hear it smooth out a lot. And the above was right, gaps make the driver see a larger enclosure(like having too big a port), and you could hurt it, while wondering why it's not delivering the performance it should.
Just my .02. Looks good btw!
 

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I feel bad pointing out that your flare isn't really a flare :sad:. Or maybe I'm seeing it wrong. It needs to be this shape.

http://www.subwoofer-builder.com/flares-25mm.htm

Don't sweat it though. You'll only hear the difference if you're pushing the limits of small-port'ness which I don't think you are. Port flaring is just icing on the cake.
 

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Discussion Starter · #20 ·
Huh... I thought a donut was an option? Would the port be better without it? How else can you flare a sonotube? Seems 8" + pvc pipe is impossible to find.
 
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