2 Jack 12's - first time cab builder

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James Champer
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2 Jack 12's - first time cab builder

#1 Post by James Champer »

(Sep 12, 2012) Okay, Now that I've taken the first few (of many I'm sure) plunges into the world of DIY speaker building, I thought I would pay back a bit and share my experiences with others. I've already been spared much heartache reading of others trials and tribulations and wanted to be sure that I contributed to that body of experience. That, and sometimes I just like to write if for nothing else, to hear.. me... type :P You know what I mean.

So here goes:

I ordered and received my full CD about two-three weeks ago (as of this writing) and after a few days pouring (and I mean pouring!) over them, this forum, and Youtube, I decided my first build would be a pair of Jack 12's since my bands play more small gigs than large and I hate lugging around the old sp2's and 118 Sub8's (80's stuff- Yow!).

So, easy enough right? Well, almost- can't make it all can I? No, of course not- so the next step was to head on over to speakerhardware.com and order some goodies.

Got the premium kit from Leland with Eminence Deltalite II 2512's, dual speakons, 32 tweets (in case I decide on melded- more on that later- or feel free to chime in with your own suggestions), chevron corners and, though I thought it a good idea at the time, I got the "handles". (changed later, you'll see what that means as we progress)

I also ordered quad top hats, needed since my front light bar is designed to pop into the top of the "top" PA box. I'll let you use your imagination on that one till I provide pics (hehe)

Now that I'm ready to build, I'll do what I've seen many here do, post each day's accomplishments in separate posts.

So away we go!
Last edited by James Champer on Sat Jun 20, 2015 2:59 pm, edited 1 time in total.
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James Champer
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Re: 2 Jack 12's - first time cab builder

#2 Post by James Champer »

Day 1: (Sept 6, 2012)

While I found a great source for nice 5x5 5ply baltic birch panels on Indy's northwest side (Thanks Rugby!), and picked up four of them, I still didn't have any hardware. So, I did as almost anyone would that couldn't stand to sit and not build, I started working on my jigs.

Grabbed some 3/4" MDF and oak from my local big box to begin and as you can see, completed my table saw jig!
IMAG0373.jpg
I also took this opportunity to build my circular saw jig and even built a jigsaw jig. (good name for a bluegrass tune don'cha think?)
IMAG0377.jpg
BTW, it ended up that the latter was for naught as we'll learn later. But I did have the spare oak and some 3/4 plywood that I was itching to get out of a corner of my garage :P

Some of you might find it interesting that, as I was contemplating the table saw jig, which happens to be one of those $300 craftsman jobs with the "T" rails, I was totally unsuccessful in locating spare rails to use as runners. My solution? Why, upgrade to the next level in craftsman table saws of course! And by "upgrade", I mean I took a grinder to that sucker and cut off those infernal T tabs so now my slots are smooth as silk!
IMAG0375.jpg
And wouldn't you know it, the 3/4x3/4" oak runners I made now slide in them with ease!

Pro tip: Try rubbing some candle or beeswax on your runners for buttery smooth goodness!

Finally, life got in the way so I had to stop for now.

Total time spent: 2.5hrs

.
Last edited by James Champer on Sat Jun 20, 2015 9:05 am, edited 1 time in total.
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Bas Gooiker
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Re: 2 Jack 12's - first time cab builder

#3 Post by Bas Gooiker »

thintheherd wrote:Pro tip: Try rubbing some candle or beeswax on your runners for buttery smooth goodness!
Thats what they did with the Jamaican athletics team!!

Your going at this well prepared. :clap:
Life is just a game, don't take it to seriously!

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Re: 2 Jack 12's - first time cab builder

#4 Post by James Champer »

Day Two: (Sept 9, 2012)

Back at it, my hardware has arrived (thanks Leland!) and now I feel like I can begin. Time to mark and cut some wood! Using the cut sheet in the plans, I begin by rough cutting all of the pieces I can out of the first two sheets of ply. Since I'm building two, I cut in pairs, that is, both sheets stacked and cut at the same time.

All goes according to plan. Until that is, I get to the smaller pieces. I ended up making one of the worst rookie mistakes (And I'm no rookie!) and cut a few on the "good" side of the line. That is to say, some of my pieces were about an 1/8th inch off. (ugh) I'm so embarrassed to even mention it- but hey, if it helps someone else avoid that idiotic move, then it's for the best I suppose.

With that ugliness out of the way, you'll notice that did not make my circular saw jig 4000ft long and I had 5x5 sheets to cut. What to do? Well, I ended up using one of the spare 5x5 sheets as my fence and that worked out perfectly.
IMAG0379.jpg
I also learned (yet again) that plywood blades are more for the salesman than the woodsmith. Those damn things burn wood for me more that cut smooth for some reason. I don't know why I keep buying them. Never again. Fortunately my fears of shard cutting were unfounded as my trusty all-purpose carbide tipped blade made smooth, tight, trouble-free cuts from here on out.

So, now that I have my pieces cut and ready, and after marking my top/bottoms with the proper markings, I start working on what I know is going to be the toughest part- the dreaded "baffle".

I'm thinking; "Hey, I've done this sort of thing before, how tough could it be?" Answer, not so tough really, with the right tools. I'm reminded of another poster that equated building with a jigsaw equated to passing a bowling ball through ones rectum and I couldn't agree more.

I started as you see below.
IMAG0384.jpg
Made my cuts and then examined them.
IMAG0385.jpg
It was then I found out that, although my cuts looked nice as I was cutting them, upon closer inspection it turns out that my blades have a tendency to flap in the wind on the underside of the work! I mean really, how does a blade manage to steer around so many clusters of wood cells when it's clearly being told to fly straight? It's like the two parts of the blade are on different missions. The deception is clear, the top part of the blade is clearly covering for the whimsical nature of his brother below.

Long story short. I ended up tabling those pieces and cut new ones.

Had I only listened to another poster that suggested this type of jig:
IMAG0390.jpg
Took a bit more time but oh man, was it worth it. Routed that sucker and happiness ensued!

Yeah, the wood burned a little (thanks to an el-cheapo Harbor Freight bit with no bearing) but rest assured, the results were night and day!

But that takes us into day 3..

Time spent day two: 6hrs

.
Last edited by James Champer on Sat Jun 20, 2015 9:10 am, edited 1 time in total.
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Re: 2 Jack 12's - first time cab builder

#5 Post by James Champer »

Bas Gooiker wrote:
thintheherd wrote:Pro tip: Try rubbing some candle or beeswax on your runners for buttery smooth goodness!
Thats what they did with the Jamaican athletics team!!
Hehe, yeah, I bobsledded once in a dream- hence the idea :D
Bas Gooiker wrote:Your going at this well prepared. :clap:
I sure hope so!

.
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Re: 2 Jack 12's - first time cab builder

#6 Post by James Champer »

Yay! Today my stoop sprouted Tweeters!
IMAG0400.jpg
Last edited by James Champer on Sat Jun 20, 2015 9:12 am, edited 1 time in total.
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Re: 2 Jack 12's - first time cab builder

#7 Post by James Champer »

Ah day three (Sept 11, 2012)

Is it time to assemble stuff!?! Well, let's see... After cutting the top hat holes in the port ducts and cutting the throat faces to the appropriate angle, I test fitted and then, wait for it...

Glued 'em together!!
IMAG0394.jpg
Sweet day! This is the point where you really feel like you are doing something!

Speaking of cutting the throat (no pun, and other angled cuts) I pondered this a great deal as I don't at all trust the gauge on the blade adjuster. So while staring blankly at a host of angle measuring tools at my local hardware warehouse, it occurred to me that there must be a better way than plunking $30+ down on a gauge I would probably use less than a few times.

Then it hit me- I've already played with one- On my Droid smart phone!! In fact, it was one of the first app downloads I messed with called the XClinometer. It has a bubble level AND an angle gauge- Perfect! So I dusted it off (opened the app) and used it to level the table. (scrap wood use win!)

..and then I rolled the blade adjuster on my table saw until I had my perfect angle!

Pictures don't do it justice but believe me, it was pure awesomeness! Especially since the gauge I mistrusted proved me right :lol: It was only a "little off" hehe.

After all that good stuff happened, I even had enough time to test fit before beer time!
IMAG0399.jpg
Another poster mentioned that cleaning up PL on all joints visible, about an hour after assembly, and they couldn't have been more right. A sharp chisel is your best friend then and it's sooo easy. Just like the availability of an air brad nailer btw. Not braggin' that I have one, but I gotta tell ya, it's the best $20 I ever spent (not that I'm a HF slut :P )

So- Day three: 3hrs

And there, all caught up on updates. I have a full day to work on them tomorrow and now that I'm in, I'll keep going with the updates.

.
Last edited by James Champer on Sat Jun 20, 2015 9:18 am, edited 2 times in total.
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Tom Smit
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Re: 2 Jack 12's - first time cab builder

#8 Post by Tom Smit »

Sweet app! ....and good progress too!
TomS

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James Champer
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Re: 2 Jack 12's - first time cab builder

#9 Post by James Champer »

Tom Smit wrote:Sweet app! ....and good progress too!
Thanks and yes, it's a killer little freebie app.

It did, however, give me pause and I had to wonder.. exactly what sort of cretins poured the concrete slab that I call my garage floor? And why did they chose to emulate the surface of a rather angry ocean when doing so?
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Re: 2 Jack 12's - first time cab builder

#10 Post by Grant Bunter »

thintheherd wrote: It did, however, give me pause and I had to wonder.. exactly what sort of cretins poured the concrete slab that I call my garage floor?
"Oh you want it flat and level, sure thing, that costs three times as much..."

Nice build to date!
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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James Champer
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Re: 2 Jack 12's - first time cab builder

#11 Post by James Champer »

Grant Bunter wrote:
thintheherd wrote: It did, however, give me pause and I had to wonder.. exactly what sort of cretins poured the concrete slab that I call my garage floor?
"Oh you want it flat and level, sure thing, that costs three times as much..."

Nice build to date!
Thanks and I know-right?

You can have it good, fast or cheap.. pick two :P
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LelandCrooks
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Re: 2 Jack 12's - first time cab builder

#12 Post by LelandCrooks »

Good thread
If it's too loud, you're even older than me! Like me.
http://www.speakerhardware.com

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Re: 2 Jack 12's - first time cab builder

#13 Post by James Champer »

LelandCrooks wrote:Good thread
Thanks Leland,

Have you figured out yet that I'm the guy who couldn't find the tweeters in my first order? :lol:

As you can see I got them yesterday, along with the adjustable top hats. Though I don't know if I'm actually going to use them on these two cabinets just yet. They are huge compared to the standard steel ones.

I'm looking through the threads as we speak to see if anyone has posted their experience with them in the jacks. As a safety measure, I cut just for the steel ones and if you haven't noticed just yet, ordered two more of those from you yesterday :)

.
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James Champer
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Re: 2 Jack 12's - first time cab builder

#14 Post by James Champer »

And just like magic- LAB 12's!!
IMAG0409.jpg
:hyper:

Awesome shipping speed Leland, thanks! I await patiently for box two on that order :wink:

Looks like the t39's are gonna be started today! Whoo hoo!

Build thread numero dos can't be far behind- hehe.

.
Last edited by James Champer on Sat Jun 20, 2015 9:20 am, edited 1 time in total.
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Re: 2 Jack 12's - first time cab builder

#15 Post by jswingchun »

Fun thread, keep it up!
Omni 10
Omni 10.5
OmniTop 12 x 4
Wedgehorn 8 x 3
XF212
T39 @ 18" x 2
T39 @ 20" x 2
T39 @ 28" x 2
Jack 110 x 5
Jack Lite 12
XF210
XF210 (Slant only, no crossfire)

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