Dual Loaded Table Tuba by a Teenager

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Gregory East
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Joined: Sat May 13, 2006 9:56 pm

Re: Dual Loaded Table Tuba by a Teenager

#151 Post by Gregory East »

Read the whole sentence and then the bit in brackets, fool! :mrgreen:

I think I told you this story before. I put 7V or 8V max into my 8ohm BAT and the thumping was clearly audible outside the bar, downstairs in the rain, while trucks were going past.

From my BAT thread:
Running some test tones in my apartment it kind of felt like poking a gorilla with a stick. Got up to 9V at 25 Hz producing a satisfactory rumble with no sign of any chuffing or rattling. 1.5V at 50Hz was getting unsociable due to the building rumbling, I'd say it's a boy!
Yours will be roughly 6dB better sensitivity, that was why you built it with two drivers and double wide wasn't it? You better know how to curb your enthusiasm with this beast or you will hurt things.
BAT10, Bad Auto Tuba. Reverse folded TAT to fit JBL 1014D, 350W driver, voltage limit unknown.

bassmonster
Posts: 1384
Joined: Wed Jul 13, 2011 9:23 am

Re: Dual Loaded Table Tuba by a Teenager

#152 Post by bassmonster »

Ate dinner and got tired after eating, so nothing else done tonight. Here are pics.

Panel 10 attached...I had to make a Lowes run for a small 2ft by 2ft sheet of 1/2 ply, since I only had ply left for panels 11, 12, and 13. :o That's why Panel 10 has a different color and grain pattern from the rest.

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Panel 11 attached...

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I'm really pleased with the way the whole thing is coming together. After you get the driver baffle panel all fixed, things really go a lot faster, like Tom Smit confirmed.

If I have time tomorrow I might be able to finish her up.

BTW, I'm so glad I didn't use MDF. It's already quite large and awkward to move it around, I can't imagine how much more bulky it would be if it were 100+ pounds.
Last edited by bassmonster on Sat Feb 04, 2012 11:15 pm, edited 1 time in total.

Gregory East
Posts: 3495
Joined: Sat May 13, 2006 9:56 pm

Re: Dual Loaded Table Tuba by a Teenager

#153 Post by Gregory East »

Back of envelope calculation of spl
95dB 1W/1m sensitivity single driver halfspace>
101dB corner loaded>
107dB dual driver double wide>
10V makes 25W add 12dB for power 119dB 1m corner loaded.

Your Mum can scream how loud? :mrgreen:
BAT10, Bad Auto Tuba. Reverse folded TAT to fit JBL 1014D, 350W driver, voltage limit unknown.

bassmonster
Posts: 1384
Joined: Wed Jul 13, 2011 9:23 am

Re: Dual Loaded Table Tuba by a Teenager

#154 Post by bassmonster »

Gregory East wrote:Read the whole sentence and then the bit in brackets, fool! :mrgreen:

I think I told you this story before. I put 7V or 8V max into my 8ohm BAT and the thumping was clearly audible outside the bar, downstairs in the rain, while trucks were going past.

From my BAT thread:
Running some test tones in my apartment it kind of felt like poking a gorilla with a stick. Got up to 9V at 25 Hz producing a satisfactory rumble with no sign of any chuffing or rattling. 1.5V at 50Hz was getting unsociable due to the building rumbling, I'd say it's a boy!
I don't recall you telling me that story, but that is something! A little T-amp could get that screaming! Wouldn't it be fun to show up at an SPL comp with a small T amp and a couple of AA batteries and totally floor the multiple battery/high output alternator guys.
Yours will be roughly 6dB better sensitivity, that was why you built it with two drivers and double wide wasn't it? You better know how to curb your enthusiasm with this beast or you will hurt things.
That, plus me wanting to have not just a single loaded cabinet, but a dual loaded cabinet! Makes things 2x as impressive. :mrgreen: Plus, I like the idea of a 24 inch wide cabinet. Don't know why, but 24 inches just seems like a perfect width. In my mind, it gives the perfect combination of optimal response~practicality/manageability.

Of course, I'll have to keep the gain at bay until I get her in the car, where people would only be exposed to the annoyance for a few seconds as opposed to constantly. My teenage neighbor used to have a garage band and played his drums upstairs with the window open every day, it resonated across the entire neighborhood. Now it's my turn. :twisted: [J/K of course, the first call to the cops and the TT would probably be burned in front of me]

67baja
Posts: 931
Joined: Sat Dec 11, 2010 12:10 am
Location: Las Vegas, NV

Re: Dual Loaded Table Tuba by a Teenager

#155 Post by 67baja »

Be careful of the gasket on those JBL's. I installed my JBL gto1002d tonight in an autotuba and cannot get the gasket to seal around 2 or 3 of the bolts. I have the bolts cranked down pretty tight, but still have air leaks. Be sure to check it closely! If I cannot get it to seal, I will end up caulking it to the baffle. Oh, and it's a real joy to put the bolts in with only one access panel, too. That 10" driver takes up a lot of the room...
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.

bassmonster
Posts: 1384
Joined: Wed Jul 13, 2011 9:23 am

Re: Dual Loaded Table Tuba by a Teenager

#156 Post by bassmonster »

67baja wrote:Be careful of the gasket on those JBL's. I installed my JBL gto1002d tonight in an autotuba and cannot get the gasket to seal around 2 or 3 of the bolts. I have the bolts cranked down pretty tight, but still have air leaks. Be sure to check it closely! If I cannot get it to seal, I will end up caulking it to the baffle. Oh, and it's a real joy to put the bolts in with only one access panel, too. That 10" driver takes up a lot of the room...
Thanks for the info. I sanded the baffle as smooth as possible. My GTOs came with a small roll of gasket tape, so I'll do my best to work with that. As for the caulk, I thought silicone broke down the foam surround on speakers? If not, I'll run some caulk around it too if I have leaks.

67baja
Posts: 931
Joined: Sat Dec 11, 2010 12:10 am
Location: Las Vegas, NV

Re: Dual Loaded Table Tuba by a Teenager

#157 Post by 67baja »

I will probably use Dap kitchen/bathroom latex caulk. There is no silicone in it, it stays flexible for a year or more (after which time it gets hard as h3ll), and is waterproof/airproof.
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.

Sydney

Re: Dual Loaded Table Tuba by a Teenager

#158 Post by Sydney »

As for the caulk, I thought silicone broke down the foam surround on speakers?
Nope.
( I've used it for close to 40 years and never had an issue )

bassmonster
Posts: 1384
Joined: Wed Jul 13, 2011 9:23 am

Re: Dual Loaded Table Tuba by a Teenager

#159 Post by bassmonster »

Sweet. That's what I'll do then, I'll make a small ring of Dap for extra insurance. Thanks for clarifying.

bassmonster
Posts: 1384
Joined: Wed Jul 13, 2011 9:23 am

Re: Dual Loaded Table Tuba by a Teenager

#160 Post by bassmonster »

How many ohms does the TT add to each driver? It's not in the plans.

Edit, never mind, it's 2 ohms per driver, a simple search answered this question. :owned:

bassmonster
Posts: 1384
Joined: Wed Jul 13, 2011 9:23 am

Re: Dual Loaded Table Tuba by a Teenager

#161 Post by bassmonster »

Early this morning I attached Panel 12. One of the braces was a little short so I laid on the PL and shoved in a shim, it worked fine. I might need another tube of PL just for the last side. :o

Image

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It's so close now! :hyper:

Titanium Hand
Posts: 559
Joined: Mon Sep 05, 2011 4:32 am
Location: Sydney, Australia

Re: Dual Loaded Table Tuba by a Teenager

#162 Post by Titanium Hand »

Maaaan you're getting close now Bassmonster, its looking good. I loved the feeling of looking down at the cab, into the horn path, just before attaching the final panel. They look so intricate and well engineered, blew a few of my non-believer, old car audio mates away looking into the timber snail Their eyes lit up with joy a few weeks later upon listening to them of course.

Hold Fast now, only a few crucial steps left!
Built 2 x T39 Lab 12 loaded 457mm wide, 29inch Wide Dual Lab 12 Loaded T60 and 2 x OTop 112 2512 Melded. Powered by N.I.TRAKTOR Pro 2.6 (2.6.1 has too many issues) TRAKTOR KONTROL S2 Crown XTi2000

bassmonster
Posts: 1384
Joined: Wed Jul 13, 2011 9:23 am

Re: Dual Loaded Table Tuba by a Teenager

#163 Post by bassmonster »

Titanium Hand wrote:Maaaan you're getting close now Bassmonster, its looking good. I loved the feeling of looking down at the cab, into the horn path, just before attaching the final panel. They look so intricate and well engineered, blew a few of my non-believer, old car audio mates away looking into the timber snail Their eyes lit up with joy a few weeks later upon listening to them of course.

Hold Fast now, only a few crucial steps left!
Thanks Titanium Hand! The design just looks so good. I wonder if there will ever be one made out of 1/2" Plexiglass and clear bathroom caulk. That would be gorgeous. (And heavy!)

Titanium Hand
Posts: 559
Joined: Mon Sep 05, 2011 4:32 am
Location: Sydney, Australia

Re: Dual Loaded Table Tuba by a Teenager

#164 Post by Titanium Hand »

Hectic! Although it would give away some of the mystery of the "Fitzmaurice Labyrinth"

From memory you tube user Sleeperawaken made a standard T48 Access cover from Plexiglass. I think just the final side on the casket made from plexiglass / perspex / lexan would be good enough.

Back in high school Design & Technology, we built perspex money boxes. Using a very basic, purpose built folding machine, we built the box from a single piece. It heated up the perspex along the bend line, you could set 'stops' like on a sheetmetal brake press to fabricate repeated, accurate bends. Piece of piss really. With that machine you could knock up a cab you were familiar with, as easy, if not easier than with wood.
Caulk would likely be redundant, as there would have to be some form of solvent adhesive, like plumbers use to join PVC pipes, that fuse the two surfaces together. The internal horn path would be rather straight forward exercise to fold out of one continuous piece becoming the front, top, back and bottom of the cab. Once the necessary allowances were made for material consumed by the radiuses of course. The driver chamber another piece. Two more for the sides and wool' ah! Done, masterpiece artwork. The bracing would present the usual challenges, although with accuracy you could fuse the braces in position on one side before bending the panel back onto the other side to prevent smearing. Bloody expensive I would imagine.

Retail electronic stores round here sell a spherical fourth order (maybe) bandpass subwoofer made from clear rigid plastic of some origin. Its only the size of a basketball for a 2.1 computer system but uber cool none the less.

Food for thought
Built 2 x T39 Lab 12 loaded 457mm wide, 29inch Wide Dual Lab 12 Loaded T60 and 2 x OTop 112 2512 Melded. Powered by N.I.TRAKTOR Pro 2.6 (2.6.1 has too many issues) TRAKTOR KONTROL S2 Crown XTi2000

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Tom Smit
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Location: Sarnia, Ont. Canada

Re: Dual Loaded Table Tuba by a Teenager

#165 Post by Tom Smit »

Wow, almost done, and how long has this journey been?
TomS

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