Tuba 24 or Tuba 30?

Combining subs, tops and all the rest of your kit.
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Jstarr1
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Re: Tuba 24 or Tuba 30?

#31 Post by Jstarr1 » Thu Apr 20, 2017 7:22 pm

Is that a venue where there's a speaker IN the audience, spaced every other patron?? :noob:[/quote]


Just about... if I remember correctly, there ended up being about 150 people there, hiding under the shade from my tent or the trees on the edges of the park...

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Tom Smit
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Re: Tuba 24 or Tuba 30?

#32 Post by Tom Smit » Fri Apr 21, 2017 1:22 am

Jstarr1 wrote: I'll have to add photos tomorrow from my computer. I guess my resolution on my phone is too high to upload.
Read this...
http://billfitzmaurice.info/forum/viewt ... f=7&t=7603

I have to look at it every now and again.
TomS

Jstarr1
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Re: Tuba 24 or Tuba 30?

#33 Post by Jstarr1 » Sun Apr 30, 2017 7:48 pm

Not fully done yet, but almost there with #1
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Jstarr1
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Re: Tuba 24 or Tuba 30?

#34 Post by Jstarr1 » Tue May 02, 2017 5:59 am

Some photos of the build.
** I am NOT a carpenter by any means, and have VERY limited tools and skills **
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Jstarr1
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Re: Tuba 24 or Tuba 30?

#35 Post by Jstarr1 » Tue May 02, 2017 6:00 am

...and more photos...
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Jstarr1
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Re: Tuba 24 or Tuba 30?

#36 Post by Jstarr1 » Tue May 02, 2017 6:02 am

...and last...
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Jstarr1
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Re: Tuba 24 or Tuba 30?

#37 Post by Jstarr1 » Tue May 02, 2017 6:17 am

I lied... Just found more on my phone.
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Jstarr1
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Re: Tuba 24 or Tuba 30?

#38 Post by Jstarr1 » Tue May 02, 2017 11:19 am

Under the gun now...
I have exactly 1 month to have another one of these built, tested, and ready to go...
Nothing big, but bigger than my single 15" front loaded subs can handle.
Hoping I don't make as many mistakes on the 2nd one. I ran into a lot of stupid issues as I was trying to cram through.
If I had taken my time, things definitely would have taken less time.

*I didn't cut the ring the speaker mounts to properly so a couple of the T-Nuts are right on the edge of the ring.
*I didn't glue the T-Nuts in place, and I was rushing to install the driver. I cross-threaded one hard, and dropped 2 more into the cabinet while trying to tighten them. In my rush, I made the initial decision that it was okay to leave like that.
*I realized my errors after sleeping on it, and cut the cross-threaded bolt head off with a 4" grinding wheel. This was nerve racking since I was cutting right against the $200 LAB-12...
*I glued the T-Nuts that fell back into place, and found that one of the screws was blocked by the cover mount. I had to drill an access hole for the allen wrench, and cut the screw shorter so it would fit in easier. When I installed this screw... That T-Nut dropped into the cabinet so I had to remove the driver again and glue that one in place. I think it took me 4-5 times before I successfully installed the driver.
*The top of the speaker has a slight bow to it so the 2nd side doesn't meet properly in the middle. I didn't notice this until I was sanding, and it was too late to do anything.
*The front of the speaker did not line up properly to the 2nd side. It is also off about 1/4". I was originally going to install a filler piece, cut it straight, and fill the crack, but chose to ignore it instead.
*I chose 3/4" plywood since I couldn't find 1/2" locally that met the guidelines in the instructions. I am hoping this wasn't a mistake... I now feel trapped, that any future cabinets need to be made from 3/4". I am not worried about weight, but the acoustics of the cabinet. I haven't been able to test it at any real levels yet, and don't honestly know what to expect when it goes out. Since I have a job for it in a month, and don't have time to rebuild it, I'm praying... (A month sounds like a lot of time except that I work 1 hour from home, and do 12 hour days. On the weekends, I am typically at horse shows with my daughter so I can only build late into the evening when it's not raining). This speaker was mostly built under a pop-up canopy in the pouring rain with water running down my backside.

Grant Bunter
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Re: Tuba 24 or Tuba 30?

#39 Post by Grant Bunter » Tue May 02, 2017 2:43 pm

Hmmm.
I think you should hire some gear for the gig coming up.
No point in putting yourself under pressure.

And, you should start over again, including the sub you built, especially if you didn't redraw the plans based on using 3/4" ply.

Have you thoroughly leak tested your first build?
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.
Bunter's Audio and Lighting "like"s would be most appreciated...

Jstarr1
Posts: 34
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Re: Tuba 24 or Tuba 30?

#40 Post by Jstarr1 » Tue May 02, 2017 2:51 pm

There are no leaks that I could find anywhere - if anything, I went overboard with PL.

As far as re-drawing - what would have to be redrawn to go to the 3/4"? I used the lines according to the drawings, but extended the parallel line out 3/4" instead of 1/2"... Was that a mistake?

Bruce Weldy
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Re: Tuba 24 or Tuba 30?

#41 Post by Bruce Weldy » Tue May 02, 2017 3:00 pm

Jstarr1 wrote:There are no leaks that I could find anywhere - if anything, I went overboard with PL.

As far as re-drawing - what would have to be redrawn to go to the 3/4"? I used the lines according to the drawings, but extended the parallel line out 3/4" instead of 1/2"... Was that a mistake?
If you didn't re-draw the entire box, then you changed the internal volume. Will it be noticeable? Maybe not - will perform as designed? Probably not. Will it be unnecessarily heavy? Absolutely.

Follow the plans on the next one.....you'll be happier with the outcome.

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."

Grant Bunter
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Re: Tuba 24 or Tuba 30?

#42 Post by Grant Bunter » Tue May 02, 2017 3:17 pm

Jstarr1 wrote:There are no leaks that I could find anywhere - if anything, I went overboard with PL.

OK, just asking as you were saying you had gaps.

As far as re-drawing - what would have to be redrawn to go to the 3/4"? I used the lines according to the drawings, but extended the parallel line out 3/4" instead of 1/2"... Was that a mistake?

In short, yes.
The dimensions of the path are critical for performance.
If you cut your sides as listed in the plans, then drew 3/4" lines to account for panel material, you have decreased the path width by 1/2" all the way through the cab, and hence the path length.
You've also decreased the size of the throat (where the driver begins to fire into the path) which increases throat pressure (which may become a problem for driver life).
If you totally redrew, you would have ended up with a cab whose sides where 1/2" deeper and 1/2" higher
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.
Bunter's Audio and Lighting "like"s would be most appreciated...

Jstarr1
Posts: 34
Joined: Wed Apr 05, 2017 2:43 pm

Re: Tuba 24 or Tuba 30?

#43 Post by Jstarr1 » Tue May 02, 2017 3:29 pm

Soooooo.
My biggest fear is a reality, and I made some critical fails in judgement! :wall:

Jstarr1
Posts: 34
Joined: Wed Apr 05, 2017 2:43 pm

Re: Tuba 24 or Tuba 30?

#44 Post by Jstarr1 » Tue May 02, 2017 3:32 pm

There weren't gaps - the wood just didn't end up flush with the next piece. The face extends 1/4" out from the side, but still has 1/2" of wood and PL making the connection.

The top board bows downward (toward the center of the cabinet) then meets back up at the corners. It is still a tight seal against the side though.

Jstarr1
Posts: 34
Joined: Wed Apr 05, 2017 2:43 pm

Re: Tuba 24 or Tuba 30?

#45 Post by Jstarr1 » Tue May 02, 2017 6:51 pm

If I choose to... how would I expand the drawings for 3/4" plywood?
I like the durability and sturdiness of the 3/4.

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