Dual 8" Truck Tuba

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CarterKraft
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Re: Dual 8" Truck Tuba

#16 Post by CarterKraft »

Thanks for the comments, we are having fun and he is actually in to it vs. some of the other projects we have done.
He really wants to get going on the Jack 112 Lite though.

As to the brace location yeah we made some changes for aesthetics and they might have bit us in the butt a little as you point out.
I was worried after looking at the pictures this morning that the space in that corner between 1 and 7 is too far unsupported, even though the compass showed other wise. A simple solution is a dead man behind 7 perpendicular to the face so it backs up resonance of panel 7 and supports the sides better.

Pardon the crappy paint cad, I don't have any CAD programs on this PC.
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Weldon Carter

CarterKraft
Posts: 255
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Location: DFW

Re: Dual 8" Truck Tuba

#17 Post by CarterKraft »

Hope to be testing tonight!

Before gluing on the lid.
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Weldon Carter

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Seth
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Re: Dual 8" Truck Tuba

#18 Post by Seth »

You'll be making noise in no time! Looking really good Carter :thumbsup:

May wanna sand the edge of that mouth cross brace down to wood before gluing the other side on. Give the PL some wood to bond to.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

CarterKraft
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Location: DFW

Re: Dual 8" Truck Tuba

#19 Post by CarterKraft »

Good eye Seth I can't get anything by you HAHA.

That brace has masking tape on it covered by the paint. Luckily my son caught that we hadn't removed the tape before gluing and peeled it off.
Weldon Carter

CarterKraft
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Joined: Thu Oct 22, 2020 1:46 pm
Location: DFW

Re: Dual 8" Truck Tuba

#20 Post by CarterKraft »

More pics.
Ill have to sit down and write a review with the old
RadioShack woofers, I am really impressed...
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Weldon Carter

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Seth
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Re: Dual 8" Truck Tuba

#21 Post by Seth »

Dang - dang - orangutan... that came out really nice! :thumbsup: I like how you cut that recess in there, where it meets the edge. Nice-n-clean. Great solution. Fantastic custom look that adds to the curb appeal, a lot!

By all means, do tell. How does it sound? How about compared to to that other one you had the pair of drivers in? What are you powering it with? Video?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

CarterKraft
Posts: 255
Joined: Thu Oct 22, 2020 1:46 pm
Location: DFW

Re: Dual 8" Truck Tuba

#22 Post by CarterKraft »

My crappy break time review...

It is LOUD. You saw the pix of the woofers, they are not the correct drivers period so I am not basing my thoughts of the cabinet on the drivers more evaluating the drivers from this Tuba cab to the bass reflex cab they were in.

In the reflex cab they had close to zero output, I never understood it but they were very quit. No visible excursion really. When my son found them still in the 10" PVC pipe tube cylinder they where mounted in he wanted to play them. So we hooked them up to the same amp they are on on now, a old Realistic 100w PA amp in my shop. He quickly agreed they sucked and weren't worth messing with, back on the shelf they went.

In the Tuba, they are loud. MY shop has two BR-1 bookshelf's from PE and a cheap ported 12" HT sub with a gutted plate amp running on the same Realistic 100w PA amp. This 7.5" wide truck tuba with the single 8" "ultimate" woofer outruns them by a large margin and is easily double the output of the 12".
Playing Texas Country on it you really can't get much over 5-10 watts on the analog meter before it is outrunning the tops.
Playing sweeps it rattles most all sheet metal items in the 30'x40' shop, roof tin, very large Snap On tool box, metal shelves etc.

The new subs are supposed to arrive tomorrow from Newark but I am apprehensive about putting two in there.
I think I will go ahead and cut the second hole like the first but cut a corresponding plywood plug to seal the hole, then if this box ends up in another application it will be ready for the second driver .
Weldon Carter

CarterKraft
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Re: Dual 8" Truck Tuba

#23 Post by CarterKraft »

Seth wrote: Sun Dec 20, 2020 3:10 pm Dang - dang - orangutan... that came out really nice! :thumbsup: I like how you cut that recess in there, where it meets the edge. Nice-n-clean. Great solution. Fantastic custom look that adds to the curb appeal, a lot!

By all means, do tell. How does it sound? How about compared to to that other one you had the pair of drivers in? What are you powering it with? Video?
And thanks! The cab isn't finished by a long shot, still need to flush trim then round over (should have flushed it first).
We were itching to hear some progress so we knocked a hole in it real quick. IF you try this method do the flush cutting first because the differences in panel heights made it really tricky to get the router depth set correctly to make a smooth trim through the PL+ and the outer ply.
I had to fudge around with the depth and be really careful but we got it smooth enough for the weatherstripping to seal.

I am thinking another piece of ply cut similarly and some expanded metal will make a bullet proof grill. We will see.
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Seth
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Re: Dual 8" Truck Tuba

#24 Post by Seth »

That's awesome :thumbsup: Glad you two are all smiles on the test run. Wait until you hear it in the SUV.

Personally, I'd just put the second one in. If the amp's adjusted properly and balanced with the rest of the system, it won't be too much. Will just require less voltage from the amp to get there.

And if you're content with performance of the speakers you already have installed, maybe consider saving the MCM's for another build. Pair of T18's perhaps. Or, a Table Tuba.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

CarterKraft
Posts: 255
Joined: Thu Oct 22, 2020 1:46 pm
Location: DFW

Re: Dual 8" Truck Tuba

#25 Post by CarterKraft »

Still lots in the air.
Drivers arrived early, Brown Santa is killing it!
I got the panels flush cut and the corners rounded. It looks great but I forgot to get pix..

I also found the F mod LP filter I had on the input to the amp was on the wrong input, swapped it to the correct input and found the Mic4/Phono input level mixer was set far too low (-1) raising it to 4 and the addition of the fmod completely changed the sound for the better much deeper less boomy. Another review is in order along with a video.

I got started on the saw sled, it was meant to be because looking in my UHMW stock I found a 7"x48"x3/8" piece. It was super easy to run it through the table saw and get the runners needed. a piece of 1/2" MDF will be the base and some 2x4 oak runners from a pallet will be the front and rear fences. The runners still have to be harvested from the pallet, nails removed and straightened for fence duty. I am pretty excited about it though. I might glue up some 3/4" plywood for the fences though if the pallet runners don't work out.
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Weldon Carter

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Tom Smit
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Re: Dual 8" Truck Tuba

#26 Post by Tom Smit »

I look at your woofer pics and I think "hefty, hefty hefty, wimpy, wimpy, wimpy" LOL :lol:
TomS

CarterKraft
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Re: Dual 8" Truck Tuba

#27 Post by CarterKraft »

Tom Smit wrote: Wed Dec 23, 2020 12:29 am I look at your woofer pics and I think "hefty, hefty hefty, wimpy, wimpy, wimpy" LOL :lol:
Exactly HaHa :loler:
Weldon Carter

jimbo7
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Location: St. Louis

Re: Dual 8" Truck Tuba

#28 Post by jimbo7 »

So any updates?

I was just playing around with a possible dual 10" driver TrT mockup in sketchup and this build was the inspiration
BFM builds:
XF212
T24 BP102 24"
2x SLA's 6-5" mids, 9- gt-302's
2x AT 14" MCM 55-2421
TrT 5" MCM 55-2421
AT 18" JBL GTO804
2x OT12 flat array
2x SLA Pro 2-Alpha 6's 2-Goldwoods
2x T39 24" 3012lf
Simplex 10 BP102

CarterKraft
Posts: 255
Joined: Thu Oct 22, 2020 1:46 pm
Location: DFW

Re: Dual 8" Truck Tuba

#29 Post by CarterKraft »

Sadly none on the tuba.

I have the drivers and intend to add the other driver location alongside the 1st and if it is not needed I'll make a plug to install, or possibly try the two Tandy junkers and use the MCM's for some stereo tubas.

I did finish the table saw sled and it is awesome!
I really don't know how I ever tried to use the saw with out it for cross cutting.

I found a source for BB local and hope to start on the J112L soon.
Weldon Carter

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