4X the build and minimal weight.........sorry, I'm in a mood today....Ryan A wrote:Just looking at the pictures, its hard to believe much weight would be saved. Must also take twice as long to build.
I appreciate the complexity and craftsmanship of it all, though.
T39L attempt
Re: T39L attempt
2X OTop 112, 3012HO, melded - 2X T39, 27", Lab 12 - XF 212 - 4 DR250, 2 melded, 2 straight
2 20" T39 3012LF - WH10 - WH8 - in the shop - 2 more 20" T39s
http://saltandlighteureka.org still need a trailer
2 20" T39 3012LF - WH10 - WH8 - in the shop - 2 more 20" T39s
http://saltandlighteureka.org still need a trailer

Re: T39L attempt
What one has to keep in mind is the nature of this EXPERIMENT: to make an ultra light T39, even at the expense of effort and, well, expense. Hoffman could be extended to include speed and or difficulty, and cost.
NOW, to REALLY set off some of you: money and effort being lesser considerations, I'm wondering how rigid something could be fabricated along the lines of 2 sheets of 1/16" (3 plies; see my earlier link posted) sandwiched around something like corregated cardboard, or corrugated plastic, such as you sometimes see small yard signs for lawn care or elections. Plastic undoubtedly should have better longevity via no moisture problems, at the sacrifice of cost. COMMENCE FLAMES:
NOW, to REALLY set off some of you: money and effort being lesser considerations, I'm wondering how rigid something could be fabricated along the lines of 2 sheets of 1/16" (3 plies; see my earlier link posted) sandwiched around something like corregated cardboard, or corrugated plastic, such as you sometimes see small yard signs for lawn care or elections. Plastic undoubtedly should have better longevity via no moisture problems, at the sacrifice of cost. COMMENCE FLAMES:
2 DR250s, 2 27" Lab15 T-60s, 2 30" Neo Titan 39s, 1 Autotuba...and looking for more!
Re: T39L attempt
Speaking from much experience: There is a VERY noticeable and therefore big difference in weight and for those where weight is a primary consideration it is very worthwhile. For some of my customers who enjoy good sound but do not have the strength to handle normal cabinets it is THE consideration.
Again, for most users 1/2" is the way to go but there is enough weight savings to make it worthwhile for those that desire it.
ncgrove, it's looking good! Like I stated earlier you're overbuilding IMO but it's definitely a build to be proud of!
Again, for most users 1/2" is the way to go but there is enough weight savings to make it worthwhile for those that desire it.
ncgrove, it's looking good! Like I stated earlier you're overbuilding IMO but it's definitely a build to be proud of!
Re: T39L attempt
Once you've built a few of these the effort and time is close to the same as 1/2".
Building these in composites will save slightly more weight but you're well in the realm of diminishing returns.
Building these in composites will save slightly more weight but you're well in the realm of diminishing returns.
Re: T39L attempt
Here's a little more of what I've been up to:
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- Posts: 676
- Joined: Tue Apr 30, 2013 5:56 pm
- Location: Colonial Beach VA
Re: T39L attempt
Thought of this when I saw your braces.....
Glider wing framing!
Glider wing framing!
BFM rig:
6 OT12
4 T48
4 WH8
Other:
56 box Electrotec LabQ rig
Way too many cables

6 OT12
4 T48
4 WH8
Other:
56 box Electrotec LabQ rig
Way too many cables

Re: T39L attempt
Finally got the last piece installed. Now the real work begins...
- Bill Fitzmaurice
- Site Admin
- Posts: 28916
- Joined: Tue May 02, 2006 5:59 pm
Re: T39L attempt
That's the inspiration for most of my designs, as opposed to this, which is how most commercial cabs are made:David Raehn wrote:Thought of this when I saw your braces.....
Glider wing framing!
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- Posts: 8538
- Joined: Fri Nov 27, 2009 11:37 am
- Location: New Braunfels, TX
Re: T39L attempt
Holy Swiss Cheese, Batman!!!!
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."
Re: T39L attempt
Yeah definitely couldn't have done all that without a drill press.
Now I have to get motivated to get out the can of bondo and the sander.
Now I have to get motivated to get out the can of bondo and the sander.
Re: T39L attempt
Edit: (I seem to have lost most of my post in the process of posting.)Bill Fitzmaurice wrote:That's the inspiration for most of my designs, as opposed to this, which is how most commercial cabs are made:David Raehn wrote:Thought of this when I saw your braces.....
Glider wing framing!
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So I hit up the town wide garage sales a couple towns over, and ran into an aeronautic mechanic, who happened to have a couple dozen 18"x84" pieces of corrugated honeycomb fiberglass floor boards from a decomissioned Airbus. Yada yada yada, half hour later I'm leaving with all of it in the Matrix.
I weighed a piece and computed that a 4x8 piece should weigh a hair over 20 lbs. One source puts 1/2" BB at 50 lbs a sheet. In the words of George Bailey "A man doesn't get himself in a situation like THIS every day!"
https://scontent-ord1-1.xx.fbcdn.net/hp ... e=56A934E7
Last edited by Rich4349 on Fri Sep 25, 2015 5:46 pm, edited 1 time in total.
2 DR250s, 2 27" Lab15 T-60s, 2 30" Neo Titan 39s, 1 Autotuba...and looking for more!
Re: T39L attempt
It will be a shame to put the side on and hide all that wonderful craftsmanship. Too bad you can't use clear acrylic.
2 THTs, 2 TLAH, SLA curved, 1 8-AT, 1 AT JBL 1002D, 4 Otop12s, Jack 12, TT with Eminence 10", 2 SLAs, 1 T30 slim, 2 T30s (2-10" each), SLA Pros, TrT.
Re: T39L attempt
Light done right. 

Good food, good people, good times.
4 - AT
1 - TT
1 - THT Slim
2 - SLA Pro 4x6 Alphalite
4 - AT
1 - TT
1 - THT Slim
2 - SLA Pro 4x6 Alphalite
Re: T39L attempt
Thanks guys. I had to put the cabinet on hold this week to slap this guy together:
I think it turned out pretty nice. It was the wife's idea to use the green on the inside. I'm really liking it.
I think it turned out pretty nice. It was the wife's idea to use the green on the inside. I'm really liking it.
- Chris_Allen
- Posts: 3358
- Joined: Wed Jul 11, 2007 2:43 pm
- Location: Huddersfield, UK
Re: T39L attempt
I do like the green colour, nice rack box.
(The original statement read: "Your wife has good taste, nice rack" but decided it didn't read well! 8O )
(The original statement read: "Your wife has good taste, nice rack" but decided it didn't read well! 8O )
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10