[LO4F]

So I've been asked to build a couple subs for my brother and a friend. My brother is more limited on space and will only have one, and decided ported would be best. The other really likes the look of the Ultimax drivers and wants a smaller box, thus, the title of this thread.


So for the ported build I went with the SI 18 before they are gone forever. My brother (college student) is renting a house with room mates and is limited on space and budget, so I am trying to maximize what I can with his limitations. So I could use some tweaks if needed, or if it looks good, the green light.

I plan on starting this coming Tuesday and will post pics as I go.


Dimensions are looking to be 24" tall, 22" wide, 26" deep for about 6 cubic feet. He set those dimensions since he doesn't want it taller than his TV stand which is 24 inches, or stick out further than it, which is 26 inches. The width is about how much space he has from the TV stand to the wall. So pretty limited on dimension changes.

For the port I was planning a slot port, 20.5" by 1.75" tall and around 33" long. Should give a tune of ~20hz. He mostly listens to music and plays video games.


For the sealed, I am looking at about 4 cubic feet. Nothing too fancy and should be straight forward. This will be replacing an HTIB system, so let's just say there will be plenty of head room with the Ultimax.


Both will be powered by using the iNuke 1000dsp.




I played around with WinISD and this is what I got for the 18:


SPL Plot:




Excursion:




Port Velocity:



Thanks!

 

[LO4F]

Well I'm going to start cutting panels tomorrow morning, so if anyone sees any issues or major concerns (or any other input really...) let me know.

Thanks.

 

[MemX]

Hope the build goes well

I posted some details in my (very slow

) build thread regarding LTDs suggestions to get more accurate modelling at the lower end due to parameters of a fully sealed box:
http://www.avsforum.com/t/1484604/4xsi18-cv5000-11cu-ft-a-good-option#post_24061055


and Bill FitzM also gave some great help on changing parameters to reflect stuffing the boxes:
http://www.avsforum.com/t/1488005/stuffing-a-diy-box-does-it-colour-the-sound#post_23677422


The former might change the excursion graph at the bottom end, and the latter (i.e. stuffing levels in the box to provide a response of a lower Q) may reduce the peak on the SPL graph and provide a flatter response with slower roll-off (I think?)


Either way, if you are EQing electronically then I'm sure it will be great!

EDIT: Having written all the above, I've just realised that it may all be irrelevant as you're doing a vented box not a sealed...

LoL

 

[LO4F]

No worries MemX, I am actually building a sealed Ultimax 15 as well (again for for someone else), so your post was more relevant than you thought!


I got quite a bit done in one day, i'll see if i can post some pictures later. I will say this though, a saw board is the best thing i've made so far. Made ripping my stock down super quick.

 

[MemX]

haha Cool, glad it may be of use

 

[a|F]

Good lookin avatar.

 

[LO4F]



Quote:
Originally Posted by a|F  /t/1521451/6-cu-ft-ported-si-18-subwoofer-build#post_24474978


Good lookin avatar.

Right back at ya. I'm a fan of the late 80s sophisticated sitcoms...

 

[LO4F]

This is the progress I have made thus far:


Using the saw board to cut all the panels



Then used the table saw to trim a few pieces that needed an inch or two off



Trusty router with homemade jig



15 on the left, 18 on the right



Hopefully I can start assembling and gluing soon. Fingers crossed for Saturday.

 

[MemX]

Coming along nicely now! I think your workshop is bigger than my entire apartment, I am jealous

lol

 

[LO4F]

Thanks MemX, I have sectioned off about a third of my unfinished basement for my workshop, so that would explain the size. I love it down there.

Progress is a bit slow with only 4 clamps. I don't dare go much faster than two panels a day. I could use screws to speed things up a bit, but my deadline for these is the end of April, so I am taking my time. Plus I have newborn twins, so spare time to work on projects is sparse... late nights are the only way to get things done.


Anyway, not much to show but a few clamping pics:








I do have a question here. I haven't used PL Premium before, so is this ~1/16" gap fine with a little extra adhesive? If I had a belt sander I would just sand it down. Suggestions??

 

[Martycool007]

LO4F- do you own a router? If so, pick up a flush trim bit and run it over the panel that has the odd-mis-shaped lip sticking out. That would work much better than using a belt sander , as I would imagine that using a belt sander with MDF might get pretty messy. I have personally never used a flush trim bit, but from all I have read, they work really well for cleaning up in-accurate cuts..

 

[bass addict]



Quote:
Originally Posted by Martycool007  /t/1521451/ported-si-18-sealed-ultimax-15-subwoofer-build/0_80#post_24492467


LO4F- do you own a router? If so, pick up a flush trim bit and run it over the panel that has the odd-mis-shaped lip sticking out. That would work much better than using a belt sander , as I would imagine that using a belt sander with MDF might get pretty messy. I have personally never used a flush trim bit, but from all I have read, they work really well for cleaning up in-accurate cuts..

A flush trim bit requires a wall to be used as a guide.


Are your end panels going on the outside of the end or inside? If inside then you can use a flush trim bit after final assembly. If the panels are going on the outside then I'd recommend sanding down that edge more. PL premium states it will fill up to 1/16" gap, but I prefer not to chance it if I don't have to. You could clamp a strip inside to use as a guide instead of sanding.


On a side note; I'd recommend investing in a gauge to set up your saw more accurately. This will prevent those problems, not to mention reduce the risk of kickback.

 

[LO4F]

I think I will try clamping a runner on the inside of the box and using my flush trim bit. I doubt an orbital will be able to sand a square line and I don't want to use the sanding block by hand if I don't have to.

Quote:
Originally Posted by bass addict  /t/1521451/ported-si-18-sealed-ultimax-15-subwoofer-build#post_24493381



On a side note; I'd recommend investing in a gauge to set up your saw more accurately. This will prevent those problems, not to mention reduce the risk of kickback.

I found out my square isn't, well, square... This back panel was my first cut and I just scribed the line with my square (24" metal one, not the small orange one in the pics) and after it was done, i noticed it didn't measure perfectly, so now it is only good as a straight edge. All my other panels should be good since I measured at least twice before cutting.

Not a bad idea to get a gauge anyway, with how many tools I'm planning on getting in the future, now would be a good time for it.


Thanks for the help.

 

[LO4F]

The flush trim bit with a runner inside worked a charm. Perfectly level. Thanks bass addict

Slow progress with the clamping. I wasn't getting even pressure on the inner baffle, so I had to use screws on the bottom panel, some brad nails in the middle of the inner baffle, and then repositioned all four clamps against the side panels. Looks to be more uniform judging by glue squeeze out.




Everything else is square and good to go. I had an hour last night with the house to myself, so I got all my bracing measured, cut, and ready to go for both builds. I should be able to start on the 18 assembly Saturday, hopefully.

 

[steve nn]

Looks like your plan is coming together..

 

[LO4F]

A bit more progress...

The last 2 Saturdays have been full of other things that needed my attention, but now it looks like I have the time to get these done by the end of the month.


Got some bracing done:







Glued and clamped the top piece (I added a bunch of weight besides the four clamps):




Then I flush trimmed everything before adding the front baffle, per instructions:



Nice and smooth:





Now just need to add the baffle, fill the seems, sand her down and paint... Man, I thought I was close to being done until I just typed that sentence.


Oh yeah, in the mean time start on the ported 18

 

[TheGiantPeach]


Looks awesome! Subscribed. I'm still pretty new to diy, but I did my first box by using bondo to fix my not-quite-squareness. Looks like I need to invest in a router and a flush trim bit. 

 

[LO4F]

Giant Peach, the flush trim bit is totally worth it, it is my first time using a quality one (freud) and it being the right size. Makes everything smooth and I can see sanding is not going to take too long on this one.


The 15 is ready for finishing, added the front baffle, flush trimmed it, and the woofer fits perfect. I was going to mount it and fire it up, but I have been having issues with my iNuke (trying to get it resolved in another thread), so I'll just finish painting before I fire it up... if I still have the patience.


I had some trouble lining up the baffle, but I decided to just hit it with some brads and it took care of the issue.





Flush trimmed:




Hungry for a sub:




I got all the vents painted flat black for my other build, should start on that sometime soon...

 

[LO4F]

Some good progress for a Saturday.


Got the 15's seams filled and now need to sand:




I did a dry fit for the 18:




Then glued it all together, used plenty of brads this time around, and clamped it down. I had to use screws on the bottom again due to lack of clamps:





I would say this is as complicated as I have done, with limited clamps, and this one seems to be as square as possible... Interesting how that happened. Probably because I wasn't rushed today.

 

[gijogeo]

Hi LO4F

Awesome work and thank you for the pics. I'm in the process of assembling a sealed sub cabinet for a 12" Ultimax myself and already thinking of two 15" 's.


In the sealed cabinet for your Ultimax there doesn't seem to be a bracing given from the back wall to front baffle. Don't know if I missed it in the pics or is it not needed?

Regards

Gijo