2x 19" T30's

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Charles Jenkinson
Posts: 1021
Joined: Sat Aug 06, 2011 3:25 pm
Location: Manchester, UK

2x 19" T30's

#1 Post by Charles Jenkinson » Thu Aug 15, 2013 3:31 pm

It has begun.

In true style, not following the plans.

My Dad wanted to prove out a neat access cover hole cutting method. A 0.8mm thick (actually thin) steel-cutting angle grinder blade and Japanese pull saw.
Attachments
plungecut.jpg
2xJ12L (3012HO) switchable/melded (http://billfitzmaurice.info/forum/viewt ... 30&t=18773)
2xT30 : http://billfitzmaurice.info/forum/viewt ... 30&t=20386

No sound is better than bad sound.

Michael Murphy
Posts: 343
Joined: Sun Dec 30, 2012 2:17 pm
Location: Trinidad

Re: 2x 19" T30's

#2 Post by Michael Murphy » Thu Aug 15, 2013 3:39 pm

I think thats great, was thinkin the same thing. And then come the plan experts. Follow the plans! Lol

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: 2x 19" T30's

#3 Post by sine143 » Thu Aug 15, 2013 3:52 pm

I think I built my first prototype t30 (not listed, shit 4 ply plywood) 90 percent with a japanese saw (baffle hole included)
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

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Charles Jenkinson
Posts: 1021
Joined: Sat Aug 06, 2011 3:25 pm
Location: Manchester, UK

Re: 2x 19" T30's

#4 Post by Charles Jenkinson » Thu Aug 15, 2013 5:06 pm

Well pumps, there's the letter of the law and the spirit of the law. Not always easy to convey the latter using the former.

That's it for tonight. First piece of plywood cut up with a hand saw - Dang it!, there i go again. :-)

P.S. It's going to end up 1/16 under 19" wide, due to saw kerf width. I know screws will will pull the second side to, and pl will fill, but if i can trim any banana tendencies out, its all for the better.
2xJ12L (3012HO) switchable/melded (http://billfitzmaurice.info/forum/viewt ... 30&t=18773)
2xT30 : http://billfitzmaurice.info/forum/viewt ... 30&t=20386

No sound is better than bad sound.

miked
Posts: 1209
Joined: Fri Oct 23, 2009 4:18 am
Location: San Antonio, TX

Re: 2x 19" T30's

#5 Post by miked » Thu Aug 15, 2013 9:47 pm

I never could cut a long, straight line with a handsaw. I can use a miter box, no problem, but that's not exactly rocket science. I'm jealous of you guys that can use hand tools with aplomb. I've used a small Japanese Saw to cut dowels flush, but that's as far as I've gotten with it. Keep the pics coming and good luck!

hifibob
Posts: 405
Joined: Sun Jan 20, 2013 5:53 pm
Location: Boston MA

Re: 2x 19" T30's

#6 Post by hifibob » Fri Aug 16, 2013 7:21 pm

God bless ya Charles.. You got some patience.. I look forward to the build, pics please!!

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: 2x 19" T30's

#7 Post by MissileCrisis » Thu Aug 22, 2013 11:47 am

How's it coming along friend! I too want to see these things come together.
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

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Charles Jenkinson
Posts: 1021
Joined: Sat Aug 06, 2011 3:25 pm
Location: Manchester, UK

Re: 2x 19" T30's

#8 Post by Charles Jenkinson » Fri Aug 23, 2013 3:20 am

Ok. Piccy loaded off phone. Editing on PC.

We went on holiday to Barmouth (Wales) from Friday to Tuesday, so progress has been slow. Had a good sesh last night. Am still cutting up wood. There's a hell of a lot of sawing. I know one is supposed to only cut pieces when required, to limit warping, but it's nigh on impossible to do. I need the 'bench' to saw plywood on and assemble one of the cabs so I need to practically cut everything up (except angle trim cuts) including the braces, before I start assembly. While I'm on cutting up; pieces 5 and 6 are listed as a rough length of 16" long - piece 5 is a good 3" less than that!

The main interesting thing last night, apart from sawing 46 linear foot of 12mm plywood by hand, was setting out the V plate (piccy below). I've seen one post about someone having difficulty with this. The way I did it was to measure (and mark off the length) down the sides of the wood from the square corner first. Then mark a short square line off at each of these two positions. Then mark off a 45 degree construction line from the square corner (where the ruler is!) - use 'pythagoras' to get this bob on. Then put your framing square on this line and move it away/closer to the square plywood corner until it crosses the short square lines (struck from the sides) at HALF the hypotenuse value given in the V-plate drawing. Strike that hypotenuse all the way across. Badda bing! V-plate happiness!

We have an A0 plotter at work. I've drawn the T30 cross section at full size. Am planning on printing it off at full scale and marking through the paper to try to speed things up, both the piece-board layout on the cab sides and also use for marking out the braces. The slight issue is some of the points (even though drawn and plotted to scale!) are not totally accurate position wise - I can either correct for them, or its of no consequence.
Attachments
vplate.jpg
2xJ12L (3012HO) switchable/melded (http://billfitzmaurice.info/forum/viewt ... 30&t=18773)
2xT30 : http://billfitzmaurice.info/forum/viewt ... 30&t=20386

No sound is better than bad sound.

MissileCrisis
Posts: 1128
Joined: Sat Dec 15, 2012 1:30 pm
Location: Walnut Creek, California

Re: 2x 19" T30's

#9 Post by MissileCrisis » Fri Aug 23, 2013 10:17 am

Take this with a grain of salt, I don't have the T30 plans: usually 3 inch leftover pieces are designed that way as to become a jig for glue up, so reread that part of the plans :). I've seen this in a couple of plans I've read. I have 8 sets of plans yet I've only built 4 cab types :(, gotta get building.
Built
2 x TLAH
1 Titan 39 (lab 12, 15 inch)
1 Tuba 60 (lab 12, 20 inch)
SLA Center
2 x Mini MLTP subwoofers
1 x 212 TH (custom)
2 x Mini-Karlsonators
Owned, but not built
2 x Jack 12 (2512, melded)

miked
Posts: 1209
Joined: Fri Oct 23, 2009 4:18 am
Location: San Antonio, TX

Re: 2x 19" T30's

#10 Post by miked » Fri Aug 23, 2013 12:43 pm

Your V-plate math hurt my brain. :bash: You are obviously smarter than I am. Please make me a v-plate too. :D

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Charles Jenkinson
Posts: 1021
Joined: Sat Aug 06, 2011 3:25 pm
Location: Manchester, UK

Re: 2x 19" T30's

#11 Post by Charles Jenkinson » Fri Aug 23, 2013 1:48 pm

Give over Mike. You're a sweet heart. If you are really not sure, sketch and PM me the v-plate shape and plan/given dimensions, and I'll give you some extra dimensions to make it easier.

I was thinking about you when i was sawing last night. May God add to you a dexterity of hand and mind that will amaze you. Amen!
2xJ12L (3012HO) switchable/melded (http://billfitzmaurice.info/forum/viewt ... 30&t=18773)
2xT30 : http://billfitzmaurice.info/forum/viewt ... 30&t=20386

No sound is better than bad sound.

miked
Posts: 1209
Joined: Fri Oct 23, 2009 4:18 am
Location: San Antonio, TX

Re: 2x 19" T30's

#12 Post by miked » Fri Aug 23, 2013 2:33 pm

I've been blessed by the good reverend! I'm set now! :mrgreen: Good luck with your build. You must have forearms like Popeye if you sawed all that by hand!

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Charles Jenkinson
Posts: 1021
Joined: Sat Aug 06, 2011 3:25 pm
Location: Manchester, UK

Re: 2x 19" T30's

#13 Post by Charles Jenkinson » Sun Aug 25, 2013 10:22 am

Here's a question. I got to drawing the restriction part indicated with 2 lines of equal length, approx 45mm long. Without the gusset (as per the plans), the 3rd line would be about 70mm to the internal corner, but with the gusset that I've drawn it maintains the approximate 45mm wide path. Is there a theoretically optimum shape here?
Attachments
gusset.jpg
2xJ12L (3012HO) switchable/melded (http://billfitzmaurice.info/forum/viewt ... 30&t=18773)
2xT30 : http://billfitzmaurice.info/forum/viewt ... 30&t=20386

No sound is better than bad sound.

User avatar
Charles Jenkinson
Posts: 1021
Joined: Sat Aug 06, 2011 3:25 pm
Location: Manchester, UK

Re: 2x 19" T30's

#14 Post by Charles Jenkinson » Mon Aug 26, 2013 2:53 am

So, in the picture; is this a region of pressure rather than flow, so cancellation mitigation is not required?
2xJ12L (3012HO) switchable/melded (http://billfitzmaurice.info/forum/viewt ... 30&t=18773)
2xT30 : http://billfitzmaurice.info/forum/viewt ... 30&t=20386

No sound is better than bad sound.

User avatar
Chris_Allen
Posts: 3223
Joined: Wed Jul 11, 2007 2:43 pm
Location: Huddersfield, UK

Re: 2x 19" T30's

#15 Post by Chris_Allen » Mon Aug 26, 2013 4:29 am

I've questioned this before and Bill said that's how it should be. Didn't explain why.
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

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