T39: 4 x 20", 2 x 28" completed

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Grant Bunter
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Location: Ilfracombe Queensland Australia
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Re: T39: 4 x 20", 2 x 28" completed

#61 Post by Grant Bunter »

At last, got time for a pic!

28” on the left vs 20” right:
Attachments
15286F55-16EB-4D43-9C2C-27C263AA707C.jpeg
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Strange Kevin
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Joined: Fri May 19, 2017 3:02 pm
Location: Scottsdale AZ

Re: T39: 4 x 20", 2 x 28" completed

#62 Post by Strange Kevin »

What is this now, 10 years latter? :)
(I guess only 5 years on the 28")

Looking good Grant!

For whatever reason, your 28" cab looks Wayyy bigger than my 24" T39s.
Sorry if you mentioned it earlier, but, how much more difficult is it to transport compared to you smaller ones?
Authorized Builder - Phoenix AZ.
Main Rig - 6 DR200s - 6 T48s (30")
SLA Pros for the smaller stuff.

Grant Bunter
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Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
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Re: T39: 4 x 20", 2 x 28" completed

#63 Post by Grant Bunter »

Strange Kevin wrote: Mon May 23, 2022 8:36 pm What is this now, 10 years latter? :)
(I guess only 5 years on the 28")

Looking good Grant!

For whatever reason, your 28" cab looks Wayyy bigger than my 24" T39s.
Sorry if you mentioned it earlier, but, how much more difficult is it to transport compared to you smaller ones?
G'day Kevin,
I promised pics one day, so I did lol...

I think IIRC I built the 20's out of structural pine. They feel like they weigh about the same as the 28's, which are built form non structural pine. So from that point of view, no different.

Similarly, I find the larger width easier to spin on it's wheels to wiggle sideways for example, or flip on it's side.
The only thing more difficult with the 28's is trying to reach to the other side to dead lift them, but it's just not as easy, but not impossible.

Transport? Pffft, they all roll up the ramp and into the Pantech. I have amassed enough to start going a second upper layer yet, Everything goes in (including backline) on the floor...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: T39: 4 x 20", 2 x 28" completed

#64 Post by Grant Bunter »

Well, another update!

In this thread:
viewtopic.php?t=26498

I asked about increased output by replacing the original BP102's in my 20" wide T39's with KL3010LF's.
While the output wouldn't increase phenomenally, the advantage of being able to set and forget a 50V limit for any sub of mine I use was/is very appealing.

So, lets go
Attachments
20230817_141423.jpg
20230908_115712.jpg
20230908_100947.jpg
20230908_082929.jpg
20230907_114505.jpg
20230904_154052.jpg
20230904_153934.jpg
20230903_093916.jpg
Last edited by Grant Bunter on Fri Sep 08, 2023 5:51 pm, edited 2 times in total.
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Grant Bunter
Posts: 6915
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: T39: 4 x 20", 2 x 28" completed

#65 Post by Grant Bunter »

Sorry, they're not in order, but top to bottom pics wise:
4 x KL301LF's to me.
After the mod.
Corner pieces of 1/4" ply as supports.
Baffle enlargement completed and blocks applied.
Radical Surgery.
Baffle mod jigs with driver in place. Inner basket top, outer basket bottom.
Pulled driver for the first time in errr ?13years.

My initial plan was to mount the mod jigs with ply spacers that maintained baffle angle and allowed routing.
Measuring and planning, the 3010 basket is about 1/4" larger than the BP102 basket.
So I knocked out the T nuts (these were built just around the time when recommended driver attachment was soon to become screws)
Don't let anyone tell you that epoxy won't last.
Then made the jigs.
Then I found I couldn't easily locally find a long enough router bit to do the mod.

So plan B became radical surgery.
Cut out the baffle maintaining enough to put it back in.
Added blocks for the first one as I'd knocked out the T nuts.
Added supports, modded baffle glued back in and tidied up some.
Cab 1 of 4 is done provided it passes all leak tests etc.
Driver burn in yet to be done.

Rinse and repeat so far for cab 2, except I left the T nuts in place. If they still line up afterwards, great, faster, less damage...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Seth
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Location: Sacramento, California, USA
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Re: T39: 4 x 20", 2 x 28" completed

#66 Post by Seth »

:clap:
Well done. It's amazing how good the cabs look after that much time. They look brand new!
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

Grant Bunter
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Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
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Re: T39: 4 x 20", 2 x 28" completed

#67 Post by Grant Bunter »

Seth wrote: Fri Sep 08, 2023 9:10 pm :clap:
Well done. It's amazing how good the cabs look after that much time. They look brand new!
Regular coats of paint fixes the appearance.
Can't say the same for the insides checking drivers etc...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

howiez
Posts: 382
Joined: Sun Mar 16, 2014 5:23 pm
Location: Fox Valley, Wisconsin

Re: T39: 4 x 20", 2 x 28" completed

#68 Post by howiez »

Looks awesome! I have to try some of those neodymium drivers someday. Love the light-weight possibility...

Bruce Weldy
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Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T39: 4 x 20", 2 x 28" completed

#69 Post by Bruce Weldy »

howiez wrote: Sat Sep 09, 2023 10:53 am Looks awesome! I have to try some of those neodymium drivers someday. Love the light-weight possibility...
Every BFM build I've done was been with Neos. Except the SLA as there isn't a Neo available for that. Every pound saved is worth it.

At least to us old guys.....
rdc_cfp_img_feb_06sm.jpeg
rdc_cfp_img_feb_06sm.jpeg (14.33 KiB) Viewed 10904 times

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."

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: T39: 4 x 20", 2 x 28" completed

#70 Post by Bruce Weldy »

Looking good Grant.

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."

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Tom Smit
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Location: Sarnia, Ont. Canada

Re: T39: 4 x 20", 2 x 28" completed

#71 Post by Tom Smit »

I like your "fix" Grant! I have BP102s in my 20" T39s and someday I might go with the 3012s. I hadn't quite figured out how I was going to do it but, after seeing yours, I now know how I will do it. Yee haw! Good work you done did.
TomS

Grant Bunter
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Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
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Re: T39: 4 x 20", 2 x 28" completed

#72 Post by Grant Bunter »

Tom Smit wrote: Sat Sep 09, 2023 2:17 pm I like your "fix" Grant! I have BP102s in my 20" T39s and someday I might go with the 3012s. I hadn't quite figured out how I was going to do it but, after seeing yours, I now know how I will do it. Yee haw! Good work you done did.
Tom, I think you would have to approach it differently to retrofit 3012LFs. You might almost consider taking out all panel 7(s), the panel 6 extension, and the upper access panel flange IMHO to give you the room to go to a 12".
It's one reason why I chose the 3010LF instead, but to be honest I didn't think I'd have to be quite so radical.

I guess the message for everyone else who may be about to build is: If you think you're going to upgrade later, future proof your build. For 12's, put in an adapter if you plan to go with 10's initially...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

User avatar
Tom Smit
Posts: 7457
Joined: Sat Jan 05, 2008 1:24 pm
Location: Sarnia, Ont. Canada

Re: T39: 4 x 20", 2 x 28" completed

#73 Post by Tom Smit »

Grant, you may be right. I will know for sure if you are, if (a big "if") I actually do a transplant....and I will let you know at that time. :)
TomS

Grant Bunter
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Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
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Re: T39: 4 x 20", 2 x 28" completed

#74 Post by Grant Bunter »

Got to finishing these off today!

Driver breakin:
20230911_141802.jpg
I didn't have to cut the baffle out for the last 2 cabs.
I found these circular 60 grit flap disks, which let me enlarge the driver spacing without removing the baffle.
For this revision, I nominate them MVT:
20230915_103842.jpg
Last driver in after leak test:
The dust cap on the KL3010LF sits proud by 9/16" compared to the BP102, so I trimmed 3/8" off the access cover brace for clearance.
Done!
Attachments
20230917_140406.jpg
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

User avatar
Seth
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Joined: Thu Sep 10, 2009 8:06 pm
Location: Sacramento, California, USA
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Re: T39: 4 x 20", 2 x 28" completed

#75 Post by Seth »

Grant Bunter wrote: Sun Sep 17, 2023 12:54 am I found these circular 60 grit flap disks, which let me enlarge the driver spacing without removing the baffle.
That's a phenomenally creative solution. F'n love it! Well done. :clap:
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

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