Jack 12 build problem.

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CajunPlayer
Posts: 10
Joined: Sun Feb 28, 2016 6:32 pm

Jack 12 build problem.

#1 Post by CajunPlayer »

I am building a Jack 12 for my bass rig. Everything was going along as expected till I wanted to install the horn braces. Oh, I got them in the center and all glued and tacked. Now, on to the Mouth Panel and the question.
Are the horn braces supposed to NOT touch the Mouth Panels? My Horn Braces stop about 1.5" from the front edge of the Throat Assembly. Are the Mouth Panels supposed to attach to the Throat Assembly with no additional bracing? . Did I do something wrong? I have checked and rechecked my measurements against the plans.
I have good shots of what I am talking about.

Any suggestions?

Robert in Baton Rouge, La
Jack 12 pic 1.jpg
Jack 12 pic 2.jpg

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Bill Fitzmaurice
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Re: Jack 12 build problem.

#2 Post by Bill Fitzmaurice »

You installed them facing the wrong way. From the plans: Cut two horn braces for a 112, six for a 212. Write on them how they install per the diagram. I can't see anything written on them.

CajunPlayer
Posts: 10
Joined: Sun Feb 28, 2016 6:32 pm

Re: Jack 12 build problem.

#3 Post by CajunPlayer »

I compared my pic to the plans. What is the problem?
Attach assemby to bottom.jpg

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Jack 12 build problem.

#4 Post by CoronaOperator »

An oscillating saw like this one can unglue those panels without wrecking them.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

CajunPlayer
Posts: 10
Joined: Sun Feb 28, 2016 6:32 pm

Re: Jack 12 build problem.

#5 Post by CajunPlayer »

I have one of those saws. I am still unclear as to what I did wrong based on the plans and my photos.
If I glued them facing the wrong way, what way is the right way? I am not trying to be difficult, I just don't understand what is wrong.
ra

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Jack 12 build problem.

#6 Post by CoronaOperator »

Look at your scetchup model. It looks like you didn't make them big enough.

Image

They need to go right to the edge of the vertical piece so that it will attach to the horn when that gets installed.
Last edited by CoronaOperator on Fri Sep 21, 2018 10:02 pm, edited 1 time in total.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

CajunPlayer
Posts: 10
Joined: Sun Feb 28, 2016 6:32 pm

Re: Jack 12 build problem.

#7 Post by CajunPlayer »

OMG,,,, I see the problem..... I cut the angle out on the wrong edge. The way I have them, the braces stick out past the bottom of the cab..
I feel more than stupid right now.
Thanks... Hope I did not mess anyone up.

Thank you for the help.
ra

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Jack 12 build problem.

#8 Post by CoronaOperator »

Use your ocillating saw, you can save the piece and reuse it. Those saws don't have many uses but this is one area where they shine.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

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Tom Smit
Posts: 7457
Joined: Sat Jan 05, 2008 1:24 pm
Location: Sarnia, Ont. Canada

Re: Jack 12 build problem.

#9 Post by Tom Smit »

J12brace.png
J12brace.png (178.47 KiB) Viewed 1743 times
The "green" edge should be against the throat panel, I believe.
TomS

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Bill Fitzmaurice
Site Admin
Posts: 28619
Joined: Tue May 02, 2006 5:59 pm

Re: Jack 12 build problem.

#10 Post by Bill Fitzmaurice »

Tom Smit wrote: Sat Sep 22, 2018 12:59 am The "green" edge should be against the throat panel, I believe.
+1.

CajunPlayer
Posts: 10
Joined: Sun Feb 28, 2016 6:32 pm

Re: Jack 12 build problem.

#11 Post by CajunPlayer »

Ok, I got the little jewel built. Waiting on the speaker, tweeters, handles, jack plate, jacks, feet and rhino cover kit.
I am still unclear about the tweeter array - the flat one with 3 on each side..
My sketch up does not work or again I am too dumb to get it to work.
Where exactly do you mount the tweeter array on this cab?
Is there a simple picture with the tweeters mounted in the flat array mode?
Can you share?
As for the high pass and low pass filters, expressparts.com has some pre-built for about $55. Would one of the pre-built things work on these cabs?
Thanks again for all the help. I am old and getting decrepit. Not a good place to be to build complicated cabs.

Robert Aucoin.
Baton Rouge, La

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Jack 12 build problem.

#12 Post by Bruce Weldy »

CajunPlayer wrote: Tue Sep 25, 2018 6:06 pm Ok, I got the little jewel built. Waiting on the speaker, tweeters, handles, jack plate, jacks, feet and rhino cover kit.
I am still unclear about the tweeter array - the flat one with 3 on each side..
My sketch up does not work or again I am too dumb to get it to work.
Where exactly do you mount the tweeter array on this cab?
Is there a simple picture with the tweeters mounted in the flat array mode?
Can you share?
As for the high pass and low pass filters, expressparts.com has some pre-built for about $55. Would one of the pre-built things work on these cabs?
Thanks again for all the help. I am old and getting decrepit. Not a good place to be to build complicated cabs.

Robert Aucoin.
Baton Rouge, La
The mounting placement is described in the plans under Flat Tweeter Array. Two pieces of 1" plywood running vertically. Measurements for the positioning is there.

Do not use an off the shelf crossover. If you don't want to build one, then go to https://www.speakerhardware.com/ and buy one there.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

himhimself
Posts: 599
Joined: Fri Nov 13, 2015 9:34 pm
Location: Vancouver BC & Bloomington IN

Re: Jack 12 build problem.

#13 Post by himhimself »

Don't neglect the sketchup file. Take the time to download the viewer and play with it. The 3D drawings are great in conjunction with the plans, letting you fly around and zoom into little areas and see exactly how things should fit together. Especially useful when you've read the sentence or two in the plans and are still scratching your head as to what it should look like.
2xT30 (20", 3012LF)
2xT30 (21", 3012LF)
4xOtop J-array (Beta12, melded/straight piezos)
Truck Tuba (MCM)
Next up: 2xJack12 or family of table tubas

NukePooch
Posts: 371
Joined: Mon Jun 30, 2014 8:07 pm
Location: Berea, Kentucky

Re: Jack 12 build problem.

#14 Post by NukePooch »

himhimself wrote: Wed Sep 26, 2018 9:04 am Don't neglect the sketchup file. Take the time to download the viewer and play with it. The 3D drawings are great in conjunction with the plans, letting you fly around and zoom into little areas and see exactly how things should fit together. Especially useful when you've read the sentence or two in the plans and are still scratching your head as to what it should look like.
+1
The Sketchup is worth the time to get the program working. It's invaluable.
Built:
4 Jack 112L- 3012HO, melded array
17.5 wide AutoTuba with Infinity 860w
6 Wedgehorn W6 w/ Panel Mount Piezos
2 T48 Slims (15" wide) with 3012LF
4 T48 Fattys (32" wide) with 3015LF

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Chris_Allen
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Joined: Wed Jul 11, 2007 2:43 pm
Location: Huddersfield, UK

Re: Jack 12 build problem.

#15 Post by Chris_Allen »

If it makes you feel any better, I did exactly the same, despite it being the second I had built.
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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