36" THT Low Profile, Warning lots of coffin pictures

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El dillo
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36" THT Low Profile, Warning lots of coffin pictures

#1 Post by El dillo » Fri Oct 16, 2015 4:22 pm

I am building a THT low profile, i will replace my two diy peerless xls 10" subs, hoping to get better low frequency impacts :D for movies. They say bigger is better... right? so decided to build the 36" version.
I´m halfway through the build.

Couldn´t find the PL glue here in europe but i found on the forum that someone recomended the Everbuild Lumberjack 30min Wood Adhesive gel. It´s a Polyurethane gel glue and it seems to work well.


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Last edited by El dillo on Thu Nov 05, 2015 12:02 pm, edited 1 time in total.

El dillo
Posts: 26
Joined: Sun Aug 23, 2015 6:38 pm
Location: Sweden

Re: 36" THT Low Profile, Warning lots of pictures

#2 Post by El dillo » Sat Oct 17, 2015 1:08 am

First i got confused about how many bracers to use with this width, the plans says 3 sets wider than 25". But more rigid is better so i used 4, have anybody had any problems with panels resonating? :?

Grant Bunter
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Re: 36" THT Low Profile, Warning lots of pictures

#3 Post by Grant Bunter » Sat Oct 17, 2015 3:15 am

Looking great so far :)

To many braces is way better than not enough!
Panel resonance is not always detectable, and it can account for a loss in output of around 3dB...
Built:
DR 250: x 2 (melded array) with March 2012 plans. 2 more under way with CD horn
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...

El dillo
Posts: 26
Joined: Sun Aug 23, 2015 6:38 pm
Location: Sweden

Re: 36" THT Low Profile, Warning lots of pictures

#4 Post by El dillo » Sat Oct 17, 2015 10:48 am

Ok good to know :cowboy: , i was more worried about unwanted noise.
I think im going to try a different design for the cover...

Maybe laminate ply and mdf (and braced), I also want to use T-nuts and countersunk holes for screws.

El dillo
Posts: 26
Joined: Sun Aug 23, 2015 6:38 pm
Location: Sweden

Re: 36" THT Low Profile, Warning lots of pictures

#5 Post by El dillo » Sat Oct 17, 2015 10:54 am

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How much could the internal volume of the closed chamber vary from the original design (36") without affect the sound for the worse?

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Radian
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Re: 36" THT Low Profile, Warning lots of pictures

#6 Post by Radian » Sat Oct 17, 2015 1:30 pm

Stay away from MDF. It doesn't have enough rigidity for these applications.
Good food, good people, good times.

Grant Bunter
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Re: 36" THT Low Profile, Warning lots of pictures

#7 Post by Grant Bunter » Sat Oct 17, 2015 3:16 pm

How much could the internal volume of the closed chamber vary from the original design (36") without affect the sound for the worse?
It shouldn't vary at all, other than the tolerance of panels making it 1/16" to 1/8" out.
Stick to the plans.

The chamber size in the plans is the size the chamber needs to be...
Built:
DR 250: x 2 (melded array) with March 2012 plans. 2 more under way with CD horn
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...

caddylackn
Posts: 122
Joined: Tue Apr 15, 2014 8:24 am

Re: 36" THT Low Profile, Warning lots of pictures

#8 Post by caddylackn » Sat Oct 17, 2015 7:40 pm

That is going to be heavvvy :!:

What driver are you using? What are you going to use for an amp?
16.5" AT w/ 860w
TLAHs w/ 9 mids & 16 tweets
17" THTLP w/ Dayton RSS315HF-4
16" TAT w/1060w
18" TT w/ Dayton DCS-205-4
5.5" TrT w/ DCS-205-4
T-18 w/ DCS-205-4
33" THT w/ Dayton Titantic 1200
Building--DR200s

El dillo
Posts: 26
Joined: Sun Aug 23, 2015 6:38 pm
Location: Sweden

Re: 36" THT Low Profile, Warning lots of pictures

#9 Post by El dillo » Sun Oct 18, 2015 6:30 am

It shouldn't vary at all, other than the tolerance of panels making it 1/16" to 1/8" out.
Stick to the plans.
Ok, it just seems like the cover in a 36" needs more stabaility, Bracing it may be enough then.


That is going to be heavvvy :!:

What driver are you using? What are you going to use for an amp?

I surely hope it will not exceed the wheight of my old concrete sub enclosures :| (80kg) i almost broke my back everytime i had to move them.
I think a sack trolley will do the job.

i will use the Dayton Audio RSS390HF-4 driver with an extra gasket connected to one channel from a stereo amp (upgrade comes later) and the crossover is in the AV- reciever.

El dillo
Posts: 26
Joined: Sun Aug 23, 2015 6:38 pm
Location: Sweden

Re: 36" THT Low Profile, Warning lots of pictures

#10 Post by El dillo » Sun Oct 18, 2015 6:51 am

6/2 bracers

I was thinking it needed the airflow so i made all of the panel 6/2 bracers with an cutout (for the driver), the bracers that are not oppsite the driver should these be without? :conf:

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Tom Smit
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Re: 36" THT Low Profile, Warning lots of pictures

#11 Post by Tom Smit » Mon Oct 19, 2015 12:11 am

You can leave those 6/2 braces as is because it does not matter. The only reason for the notches is so that the driver will not contact the braces.
TomS

El dillo
Posts: 26
Joined: Sun Aug 23, 2015 6:38 pm
Location: Sweden

Re: 36" THT Low Profile, Warning lots of pictures

#12 Post by El dillo » Tue Oct 20, 2015 1:50 pm

Test fitting the other side panel... :shock:
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Some misalignment to fix :wall:
I also had to do some planing and grinding on the width panels because of height differences.
It was all cut at the workshop :cussing:

El dillo
Posts: 26
Joined: Sun Aug 23, 2015 6:38 pm
Location: Sweden

Re: 36" THT Low Profile, Warning lots of pictures

#13 Post by El dillo » Wed Oct 21, 2015 7:58 pm

Some Plastic Padding will fix it.
The other panels was almost perfect, but some had to be re drilled.
Bought 4 tubes of glue, almost 2 full that would be enough for the rest.

El dillo
Posts: 26
Joined: Sun Aug 23, 2015 6:38 pm
Location: Sweden

Re: 36" THT Low Profile, Warning lots of pictures

#14 Post by El dillo » Sat Oct 31, 2015 5:32 pm

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haven´t found any leaks so far... :D
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Hope this will work :roll:
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Made the lid larger, i will do some routing later when the lid is in place to get exact fit.
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I wonder if the connection panel need to be sealed with silicone or if it will be airtight just with a rubber seal.

caddylackn
Posts: 122
Joined: Tue Apr 15, 2014 8:24 am

Re: 36" THT Low Profile, Warning lots of pictures

#15 Post by caddylackn » Sun Nov 01, 2015 9:28 pm

I would add some braces perpendicular and in between those lid braces that would stiffen it up along the other axis. While those braces stiffened up the lid in the short direction, in the long direction you could get flex. If the final placement of the speaker will put the access panel in contact with the ground with the speaker throat pointing up, the extra bracing wouldn't be needed. The only way it could flex would be to lift up that 200 lb speaker :lol:
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I wonder if the connection panel need to be sealed with silicone or if it will be airtight just with a rubber seal.
Follow the leakage test in the plans. It is easy to hear air leaks in the access panel with a hose to your ear. You can always use the rubber seal, test it, if it leaks seal the entire perimeter gap of the access with clear latex caulk. It goes on as white, and dries clear. It is paintable, water clean up, and easy to cut cleanly if you ever need the access panel off again. Silicon, makes a mess and isn't paintable. It is hard to cut cleanly, it wants to tear.
16.5" AT w/ 860w
TLAHs w/ 9 mids & 16 tweets
17" THTLP w/ Dayton RSS315HF-4
16" TAT w/1060w
18" TT w/ Dayton DCS-205-4
5.5" TrT w/ DCS-205-4
T-18 w/ DCS-205-4
33" THT w/ Dayton Titantic 1200
Building--DR200s

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