Tuba 24 or Tuba 30?

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Bruce Weldy
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Re: Tuba 24 or Tuba 30?

#46 Post by Bruce Weldy » Tue May 02, 2017 10:21 pm

Jstarr1 wrote:If I choose to... how would I expand the drawings for 3/4" plywood?
I like the durability and sturdiness of the 3/4.
3/4 is no more durable or sturdy than 1/2. That's why there are so many braces. Hundreds, if not thousands, of these cabs have been built. Yet no one has ever said that one of them caved in under the pressure of loading, stacking, or even having people dance on them.

You are just adding extra weight and giving up some efficiency by changing the plans....remember, the guy that designed these knew what he was doing - if 1/2 wasn't sufficient, he would have designed them differently.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
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."

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whines
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Re: Tuba 24 or Tuba 30?

#47 Post by whines » Wed May 03, 2017 8:51 am

Yeah, with the bracing installed as specified your cab will be rock solid. Baltic Birch is really nice stuff.
2xJ15, THT, 4xT39 3012 (2x15", 2x20"), 2xSLA Pro, 2x short SLA Pro (Dayton), W6

Grant Bunter
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Re: Tuba 24 or Tuba 30?

#48 Post by Grant Bunter » Wed May 03, 2017 3:06 pm

whines wrote: Baltic Birch is really nice stuff.
Unfortunately we don't know where the OP lives.
In many places around the world, BB is horribly expensive and can be hard to obtain in 1/2".

Still, both you and Bruce are spot on, the well braced designs make them rock solid when made out of 1/2" material, whatever that material may be...
Built:
DR 250: x 2 (melded array) with March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
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Bill Fitzmaurice
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Re: Tuba 24 or Tuba 30?

#49 Post by Bill Fitzmaurice » Wed May 03, 2017 4:59 pm

Grant Bunter wrote: Unfortunately we don't know where the OP lives.
Which means that others near him can't help. And that's why it says this:
After you've been activated complete your profile, including home town. It's a lot easier to get advice on local issues if we know where local is.
here:
http://billfitzmaurice.info/forum/viewt ... =19&t=3973

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BrentEvans
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Re: Tuba 24 or Tuba 30?

#50 Post by BrentEvans » Thu May 04, 2017 6:40 am

Bruce Weldy wrote:
3/4 is no more durable or sturdy than 1/2.
In the strictest sense this is not true. Thicker plywood has less deflection and is therefore "sturdier." The issue in these cabs is that all The measurements are in place for half-inch ply, and re-jiggering the all those measurements for three-quarter ply is difficult and for dubious benefit. It just adds weight. If you were building a simple box with no bracing, the three-quarter would be a better choice.
You are just adding extra weight and giving up some efficiency by changing the plans....remember, the guy that designed these knew what he was doing - if 1/2 wasn't sufficient, he would have designed them differently.
this part is the real reason, and very well stated.
99% of the time, things that aren't already being done aren't being done because they don't work. The other 1% is split evenly between fools and geniuses.

Bruce Weldy
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Re: Tuba 24 or Tuba 30?

#51 Post by Bruce Weldy » Thu May 04, 2017 7:48 am

BrentEvans wrote:
Bruce Weldy wrote:
3/4 is no more durable or sturdy than 1/2.
In the strictest sense this is not true.
Yes, but I'll stand by that in the context of the discussion......durability meaning the abuse taken by the surface of the panel which is the same regardless of thickness and that the bracing of the box creates the sturdiness.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
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."

CoronaOperator
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Re: Tuba 24 or Tuba 30?

#52 Post by CoronaOperator » Thu May 04, 2017 8:39 am

Bruce Weldy wrote:[
Yes, but I'll stand by that in the context of the discussion......durability meaning the abuse taken by the surface of the panel which is the same regardless of thickness and that the bracing of the box creates the sturdiness.
+1 if you are subjecting these boxes to something that will shred 1/2" baltic birch with bracing every 8", then 3/4" isn't going to help your problem. As many people that fit on my boxes dance on them without any problems.

btw: Going from 1/2" to 3/4" is a 50% increase in weight :shock: , even if you do a redraw you'll eventually rebuild lighter if you move them around a lot. Nobody here is getting any younger!
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
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BrentEvans
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Re: Tuba 24 or Tuba 30?

#53 Post by BrentEvans » Thu May 04, 2017 6:50 pm

Bruce Weldy wrote:
BrentEvans wrote:
Bruce Weldy wrote:
3/4 is no more durable or sturdy than 1/2.
In the strictest sense this is not true.
Yes, but I'll stand by that in the context of the discussion......durability meaning the abuse taken by the surface of the panel which is the same regardless of thickness and that the bracing of the box creates the sturdiness.
I'd say it still depends on the application. For permanently placed cabs, cabs that are babied, or cabs with line-x, 1/2" is always enough. There is no danger of losing wood mass from wear and tear with those. If your cabs get thrown around by roadies, subjected to road rash, etc, 1/2" will start to look irreparably ratty before 3/4". For the weight savings, it's worth it most of the time.

It's just worth considering that words like "sturdy" and "durable" are subjective. My subs that are made from 3/4 cabinet grade ply with pocket screws and PL glue stand up to road wear WAY better than the DR200s made from auraco 1/2" did. Those were getting ratty very quickly so I refinished them and put them in an install (that customer got a crazy deal. Still kind of regret it). Some of that is the grade of ply, but some of it is the thickness.

I'm sure we can agree that with these designs, it is critical to keep the internals at 1/2" ply. There is no benefit to anything else. There really should be no problem, though, with anyone making the outer shell of anything they want, with the caveat that from a performance perspective, 1/2" is sufficient. The downside is weight. The upside is the possibility of greater durability if needed. Each builder should weigh the benefits, make a decision, and not be castigated for it.

:D
99% of the time, things that aren't already being done aren't being done because they don't work. The other 1% is split evenly between fools and geniuses.

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