The Stonewater Cinema Build Thread - Page 86 - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 1627Likes
Reply
 
Thread Tools
post #2551 of 3160 Old 10-23-2018, 12:29 PM
AVS Forum Special Member
 
HopefulFred's Avatar
 
Join Date: Mar 2007
Location: Atlanta, GA
Posts: 3,758
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 572 Post(s)
Liked: 530
Once you paint those cabinets, the extra thickness of the paint will keep them stuck in there by the vacuum if you ever try to pull them out! 😉
HopefulFred is online now  
Sponsored Links
Advertisement
 
post #2552 of 3160 Old 10-24-2018, 04:37 AM
AVS Forum Special Member
 
DougUSMC's Avatar
 
Join Date: Jun 2014
Location: Ellicott City, MD
Posts: 1,292
Mentioned: 44 Post(s)
Tagged: 0 Thread(s)
Quoted: 719 Post(s)
Liked: 616
Quote:
Originally Posted by TMcG View Post
I'm not sure how it ended up like this, but the sub was more like an exact fit with barely 1/8" to spare. You could feel the 'cush' of air rushing out of the back box as I slid the sub into place.
Wow, with that little tolerance, you probably don't even want to put a textured finish to the Duratex!

No sarcasm there, you likely SERIOUSLY need to stick to a smooth finish!
DougUSMC is offline  
post #2553 of 3160 Old 10-24-2018, 05:02 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by HopefulFred View Post
Once you paint those cabinets, the extra thickness of the paint will keep them stuck in there by the vacuum if you ever try to pull them out! 😉
You're not kidding! I was sincerely hoping for that 1/4" gap on either side which I planned to fill with 1/4" backer rod to act as a vibrational cushion and keep the box from moving, especially since the sub driver is mounted high and not low due to the future riser and base molding crossing in front of this box.


Morning update...

After more than a solid week of working from 3 or 4AM until 8AM and then again from 8PM until about 11PM-Midnight, I took it easy last night and only measured out my cut sheet for all eight sub boxes for the rolled poly batting. I also secured the last front baffle to the fourth DIY Soundgroup box, so all boxes are now complete.

EDIT - Realizing the "pics or it didn't happen" rule is still in effect, here's the glue-up pic for the front baffle of the fourth DIY Soundgroup box...



I am behind on pictures (again), but what you've not seen is additional work I need to do on one of the custom rear sub boxes, both due to CNC machining errors. The first should be relatively straightforward, which is filling up a gap with Bondo where the cut piece had moved. You can see the mistake here...



Close up...


I plan to apply packaging tape to two different scrap pieces of MDF, clamp the pieces with their straight edges lining up along the box's straight edge to create a perfect 'well' to fill in. I knew this had happened at the time of machining, but I accepted the piece as-is because it was already a 14-hour day at the CNC machine to cut everything.


I also need to cut a new top and bottom for one sub box. I'm not sure what setting was off at the CNC, but you can see one set was cut way too small. The set on the left fits perfectly, the set on the right does not.




Since today is going to be the last sunny day for the next 4-5 days, I plan on rolling my table saw outside and precisely cutting two new pieces, using the good pieces as my template. I also had to buy a 2" Forstner bit and 9mm drill bit to reconstitute the Speakon connector plate and threaded insert locations for the rubber feet. Once cut, it's back to more glue-up and clamping to finish the box carcasses. Hopefully I can finish all of this by tonight.

I *might* get to installing some of the poly box lining later today, but no guarantees. It's amazing how long everything takes during the box building process, especially when the highest precision is required....or should I say because the highest precision is required.
Attached Thumbnails
Click image for larger version

Name:	IMG_5223.jpg
Views:	232
Size:	64.6 KB
ID:	2472690   Click image for larger version

Name:	IMG_5222.jpg
Views:	232
Size:	120.1 KB
ID:	2472692   Click image for larger version

Name:	IMG_5178.jpg
Views:	235
Size:	103.9 KB
ID:	2472694   Click image for larger version

Name:	IMG_5177.jpg
Views:	235
Size:	88.2 KB
ID:	2472696   Click image for larger version

Name:	IMG_5269.jpg
Views:	227
Size:	98.2 KB
ID:	2472712  

LTD02 and BllDo like this.

Last edited by TMcG; 10-24-2018 at 07:07 AM.
TMcG is offline  
Sponsored Links
Advertisement
 
post #2554 of 3160 Old 10-24-2018, 05:28 AM
AVS Forum Special Member
 
markmon1's Avatar
 
Join Date: Dec 2006
Posts: 6,239
Mentioned: 106 Post(s)
Tagged: 0 Thread(s)
Quoted: 5242 Post(s)
Liked: 3406
Is there a link to which post numbers in this massive thread that shows the completed room?

Video: JVC RS4500 135" screen in pure black room no light, htpc nvidia 1080ti.
Audio: Anthem mrx720 running 7.1.4, McIntosh MC-303, MC-152, B&W 802d3 LR, B&W HTM1D3 center, B&W 805d3 surround, B&W 702S2 rear, B&W 706s2 x 4 shelf mounted for atmos, 2 sub arrays both infinite baffle: 4x15 fi audio running on behringer ep4000 + 4x12 fi audio running on 2nd ep4000.
markmon1 is online now  
post #2555 of 3160 Old 10-24-2018, 05:40 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by markmon1 View Post
Is there a link to which post numbers in this massive thread that shows the completed room?
Theater is not finished, only most of the way through drywall. The link in my signature below takes you to the pertinent part of the build process with lots of pics to follow along, but the first pics in THIS POST show you what the room build looks like as of today. I have a basement to finish which should use up all the construction and finishing materials currently stored in the theater, thereby providing a basement I can use and an empty theater room to plug away at the ceiling and finishing work.
TMcG is offline  
post #2556 of 3160 Old 10-24-2018, 08:32 AM
AVS Forum Special Member
 
brazensol's Avatar
 
Join Date: Oct 2014
Location: Wasilla, Alaska
Posts: 1,628
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 753 Post(s)
Liked: 575
When I installed my rear subs I made them fit as tightly as possible (got that same rush of air as the moved into place) and screwed them to the back wall. I was a bit worried about vibrations but am happy to say there have been none to date!
Attached Thumbnails
Click image for larger version

Name:	IMG_1752.JPG
Views:	49
Size:	372.9 KB
ID:	2472750  
TMcG likes this.

Denali Cinema
JVC-RS540, 124" Wide 2.40:1 DIY Screen, Denon 8500H, Denon 6200W, Panasonic UB820 UHD Player, (3) iNuke 6000DSP; (2) iNuke NX3000D; (3) HTM-12; (14) RSL C34e surrounds; (2) 18" DA RSS460HO-4 Subwoofers; (1) DA UM18-22 18" Ultimax Subwoofer; (4) DA RSS390HO-4 15" Reference HO Subwoofers; BOSS Platform - (12) 12" Subwoofers
brazensol is offline  
post #2557 of 3160 Old 10-24-2018, 12:16 PM
AVS Forum Special Member
 
HopefulFred's Avatar
 
Join Date: Mar 2007
Location: Atlanta, GA
Posts: 3,758
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 572 Post(s)
Liked: 530
I'm pretty sure that there will be so much output capability that no one speaker is likely to ever get even halfway to x-max. Motion should be basically nil unless there is dramatic EQ at very low frequency - even then, the search for infrasonic output would be shared among all drivers, hopefully. If they are all working in phase, output shouldn't be a problem.
HopefulFred is online now  
post #2558 of 3160 Old 10-24-2018, 02:16 PM
Senior Member
 
just jim's Avatar
 
Join Date: Oct 2012
Location: Toronto
Posts: 450
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 98 Post(s)
Liked: 65
Hi Tim Are you not concerned about the Bondo having different sound/strength characteristics from the MDF or that it will separate from the MDF if there are any atomic vibrations? My humble suggestion would be to cut a piece of MDF to fit, or bigger and glue it in. Rub carpenters glue into the surfaces to be glued and let dry. This seals the edges and prevents a "dry" final joint. When dry, coat again and clamp in place. Use wax paper so your glue blocks don't stick to the panel. Cut close and sand. The repair will be as strong as the original MDF. After all, MDF is simply glue and wood fiber.

Winterfell theatre build - working title
just jim is offline  
post #2559 of 3160 Old 10-24-2018, 05:05 PM
AVS Forum Special Member
 
markmon1's Avatar
 
Join Date: Dec 2006
Posts: 6,239
Mentioned: 106 Post(s)
Tagged: 0 Thread(s)
Quoted: 5242 Post(s)
Liked: 3406
Quote:
Originally Posted by TMcG View Post
Theater is not finished, only most of the way through drywall. The link in my signature below takes you to the pertinent part of the build process with lots of pics to follow along, but the first pics in THIS POST show you what the room build looks like as of today. I have a basement to finish which should use up all the construction and finishing materials currently stored in the theater, thereby providing a basement I can use and an empty theater room to plug away at the ceiling and finishing work.
Awesome thank you. Interested in how this turns out. As this started in 2012 I just assumed it was done a couple years ago and the photos were lost in such a long thread. haha.

Video: JVC RS4500 135" screen in pure black room no light, htpc nvidia 1080ti.
Audio: Anthem mrx720 running 7.1.4, McIntosh MC-303, MC-152, B&W 802d3 LR, B&W HTM1D3 center, B&W 805d3 surround, B&W 702S2 rear, B&W 706s2 x 4 shelf mounted for atmos, 2 sub arrays both infinite baffle: 4x15 fi audio running on behringer ep4000 + 4x12 fi audio running on 2nd ep4000.
markmon1 is online now  
post #2560 of 3160 Old 10-24-2018, 08:27 PM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by just jim View Post
Hi Tim Are you not concerned about the Bondo having different sound/strength characteristics from the MDF or that it will separate from the MDF if there are any atomic vibrations? My humble suggestion would be to cut a piece of MDF to fit, or bigger and glue it in. Rub carpenters glue into the surfaces to be glued and let dry. This seals the edges and prevents a "dry" final joint. When dry, coat again and clamp in place. Use wax paper so your glue blocks don't stick to the panel. Cut close and sand. The repair will be as strong as the original MDF. After all, MDF is simply glue and wood fiber.
Zero concerns regarding sound differences. My primary concern is regarding the adhesive bond strength as Bondo is non-porous. For this small patch area I was going to use cyanoacrylate glue to make my life easy. I totally agree with your approach of splicing in another piece of MDF as the best method or repair, but I don't have the tools or skill to pull it off. My jigsaw is crappy and never seems to be able to cut at a perfect 90 degrees. There's always 5-10 degrees of inward bend, particularly toward the bottom of the cut. I have an oscillating tool, but no real way to make a steady 90 degree cut by hand. I'm open to suggestions, but without the right tools, getting a good fit for the scabbed in piece could prove overly difficult.

The gap probably looks bigger in photos than it actually is. I'll lay my 6 foot level across it and try to illustrate the size (depth) of this gap later tonight.

Thanks for keeping me on the straight and narrow with noob woodworking exploits!
TMcG is offline  
post #2561 of 3160 Old 10-25-2018, 06:09 AM
AVS Forum Special Member
 
Waterboy77's Avatar
 
Join Date: Oct 2007
Location: Calgary, Alberta
Posts: 1,514
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 604 Post(s)
Liked: 315
And all this time I assumed you were a robot. Or is this a conscious attempt for a robot to look like a human and make a mistake.... AI is tricky LOL JK
TMcG likes this.

One day I will start the new theater....... one day..... THAT DAY HAS ARRIVED
"If the women don't find you handsome, they should at least find you handy." Red Green
Family Cave Theater
Automation Thoughts/ Questions
Waterboy77 is offline  
post #2562 of 3160 Old 10-25-2018, 06:39 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by Waterboy77 View Post
And all this time I assumed you were a robot. Or is this a conscious attempt for a robot to look like a human and make a mistake.... AI is tricky LOL JK
DOES NOT COMPUTE...uh...I mean, I don't understand....


I decided to roll with my Bondo fix plan and use CA glue and MDF screws to really secure and seal this small area

With my six foot level laying across the side, you can see the full extent of the CNC bit's damage...


Here's another angle with a board clamped from the back. Probably 3/16" deep on the left, about 1/16" on the right.


I wrapped two pieces of MDF scrap in packaging tape and brought flush with either edge with clamps.




This is my first time ever working with Bondo. I had this thing perfectly smooth and was trying to slightly overfill the left side when the Bondo went from workable to sludge in a matter of seconds. So the patch didn't look as pretty, but easily remedied by a bit of extra sanding.


Side profile of the fix after I removed the boards.


Completed patch after some light sanding


I plan to use Bondo to feather all the cut MDF edges and fill the screw holes. I'm glad I had a chance to work with this as a test case before moving to the sub box finish work in a month or two.

Quick update....
  • Work was busy yesterday and I didn't have a chance to haul out the table saw and cut the replacement top / bottom pieces for the one UXL-18 box. I definitely need to get to it today as the forecast is calling for rain and bitter cold the next three days. Once the pieces are cut I'll immediately glue them up to the boxes so I can move one step closer to completion.
  • While the table saw is out I plan on cutting 16 small pieces of 3/4" MDF to act as backers for the four feet for each DIY Soundgroup sub box. The threaded insert is nearly 3/4" deep by itself, so it will require backing to keep the box sealed.
  • I'm going to start lining the sub boxes with the poly batting, using the Super 77 spray adhesive.
  • I need to carefully align the front baffles for the 24" subs and plan out my approach to attaching everything securely since the materials are so thick. I think I have a good approach mapped out in my head, I just need to confirm as I translate it to the real thing. More on this later when I go to attach the front baffles over the next day or two.

With any luck I should have all eight sub boxes completed and ready for drivers over the weekend. I'm looking forward to being done with glue, clamps and dry times!!
Attached Thumbnails
Click image for larger version

Name:	IMG_5276.jpg
Views:	245
Size:	44.5 KB
ID:	2473250   Click image for larger version

Name:	IMG_5282.jpg
Views:	235
Size:	61.0 KB
ID:	2473252   Click image for larger version

Name:	IMG_5277.jpg
Views:	239
Size:	50.0 KB
ID:	2473254   Click image for larger version

Name:	IMG_5280.jpg
Views:	237
Size:	55.2 KB
ID:	2473256   Click image for larger version

Name:	IMG_5279.jpg
Views:	241
Size:	62.3 KB
ID:	2473258  

Click image for larger version

Name:	IMG_5281.jpg
Views:	246
Size:	84.8 KB
ID:	2473260   Click image for larger version

Name:	IMG_5278.jpg
Views:	238
Size:	58.7 KB
ID:	2473262  
TMcG is offline  
post #2563 of 3160 Old 10-25-2018, 09:19 AM
Senior Member
 
Join Date: Mar 2017
Location: Birmingham,Alabama
Posts: 294
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 135 Post(s)
Liked: 172
The bondo should hold up fine

It's used fairly often by woodworkers to make more stable fills than a "normal" wood filler could handle - generally in cases like yours where the gap is large.

Purely as an FYI the way I generally handle something like that would be to cut a fill piece about 1/16" thicker than the deepest part of the gap and wider than the panel by the same amount. I would then glue and clamp the piece and shoot a few pin nails into it. Once it dried I'd either use a flush trim bit in the router or (these days more likely) use a hand plane to bring all of the surfaces level. As someone mentioned above there wouldn't be very much difference if any in strength between the rest of the panel and the repair. This is something that often comes up in woodworking - especially in my mistake prone version of it - and you tend to get good at fixing them due to excessive practice...
p3bham is offline  
post #2564 of 3160 Old 10-25-2018, 10:20 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by p3bham View Post
It's used fairly often by woodworkers to make more stable fills than a "normal" wood filler could handle - generally in cases like yours where the gap is large.

Purely as an FYI the way I generally handle something like that would be to cut a fill piece about 1/16" thicker than the deepest part of the gap and wider than the panel by the same amount. I would then glue and clamp the piece and shoot a few pin nails into it. Once it dried I'd either use a flush trim bit in the router or (these days more likely) use a hand plane to bring all of the surfaces level. As someone mentioned above there wouldn't be very much difference if any in strength between the rest of the panel and the repair. This is something that often comes up in woodworking - especially in my mistake prone version of it - and you tend to get good at fixing them due to excessive practice...
Thanks @p3bham . I have no concerns with the strength, only the bonding...and to that end I ordered 5-minute 2-part epoxy instead of using CA glue. If it can bond non-porous glass and metal, it can hold this little 4" span to Bondo...not to mention I will have actual MDF screws on either side to help secure everything tightly.


Quick update....
Over lunch I set up my table saw and cut the new top and bottom pieces. Both pieces fit perfectly the first time and I have one box glued up and clamped as I type this. The second box will get glued / clamped later after the kids go down for bed. Here's a couple of photos.




I also cut the small blocks needed to back the threaded insert for the rubber feet for the DIY Soundgroup subwoofer box. I'll slather a bunch of glue and brad nail into place tonight for all four boxes. I cut extras just to run out the strip I had, just in case I wanted a couple extra blocks for something.


With my remaining time I precut more pieces of poly batting in accordance with my cut sheet. I should be able to start gluing all the batting into position this evening. Not sure how far I'll get.

And I arranged to borrow a hand truck this weekend. Any available time it isn't raining this weekend I will cart the 24" sub boxes outside and sand all the edges smooth, assuming I get the front baffles attached either tonight or tomorrow.
Attached Thumbnails
Click image for larger version

Name:	IMG_5284.jpg
Views:	233
Size:	74.1 KB
ID:	2473392   Click image for larger version

Name:	IMG_5285.jpg
Views:	236
Size:	59.7 KB
ID:	2473394   Click image for larger version

Name:	IMG_5283.jpg
Views:	228
Size:	108.7 KB
ID:	2473396  
LTD02 likes this.
TMcG is offline  
post #2565 of 3160 Old 10-25-2018, 11:32 AM
AVS Forum Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 21,216
Mentioned: 862 Post(s)
Tagged: 1 Thread(s)
Quoted: 2955 Post(s)
Liked: 3685
nice work on the enclosures!

lining the walls with polyfill type material won't really do anything.

impact of stuffing on subs:
https://data-bass.com/data?page=content&id=79

for big cabs, standing waves can develop. in those cases stuffing can damp them out. i don't think your enclosure is large enough for that to matter. if you want to be safe though a simply polyfill pillow or two from wally world as has been mentioned will work just fine.
TMcG likes this.

Listen. It's All Good.
LTD02 is offline  
post #2566 of 3160 Old 10-26-2018, 05:10 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by LTD02 View Post
nice work on the enclosures!

lining the walls with polyfill type material won't really do anything.

impact of stuffing on subs:
https://data-bass.com/data?page=content&id=79

for big cabs, standing waves can develop. in those cases stuffing can damp them out. i don't think your enclosure is large enough for that to matter. if you want to be safe though a simply polyfill pillow or two from wally world as has been mentioned will work just fine.
Thanks @LTD02 ! A wealth of information, as-always. Since I already cut the rolled poly material to size for the sub boxes, I'm just going to go ahead and line the boxes with it since it won't hurt anything and will add to the total amount of stuffing in the box. Per your feedback I'm also not going to obsess on the amount I load into the boxes, only making sure it's a comfortable amount.


Morning update:
* Last night my neighbor texted me that he needed a majority of his clamps back today. He's coming to pick them up around 9AM this morning. As a consequence, I set alarms on my phone to go off all night long so I could continue to glue and clamp everything I could approximately 3.5-4 hours apart. That's shorter than I like to leave things clamped up, but certainly should hold without breaking according to Titebond's website on cure time vs. bond strength. I added 18 gauge brads every 2" along the seams as I unclamped just to be extra sure of the hold. The good news is I finished all the tops and bottoms to the custom 18" rear sub boxes.

* Because I won't have clamps, I won't be able to secure the front baffles to any of the custom subs this weekend I'll do all I can to prepare for when the clamps are back in-hand.

* My Father-In-Law is a shadetree woodworker, taking on small crafts and light duty carpentry work...nothing big. I was running him through my 24" sub box baffle attachment plan and he was able to offer two slight tweaks to my plan to make things go a little bit more smoothly. We tested the approach on the double 1.5" layer scrap material I kept from the sub driver cutouts. More on the actual attachment plan when I attach the baffle and can post the pictures in the coming week.

* I placed an order from McMaster Carr for more installation 'stuff', including some shorter hex bolts, lock washers and oversized washers to attach the feet. I also had to order much longer hex bolts to secure the 24" sub drivers properly, given the 3" thickness of the front baffle. If you haven't ordered from them before, consider them for your next purchase. I ordered a bunch of little crap yesterday afternoon and it's being delivered today for just $7 ground shipping. Website is also a cinch to navigate and find exactly the right parts.


More to follow this weekend. Happy Friday everyone!
mikela, LTD02, ereed and 3 others like this.

Last edited by TMcG; 10-26-2018 at 06:39 AM.
TMcG is offline  
post #2567 of 3160 Old 10-29-2018, 05:23 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
BHS-24 Front Baffle Build

I hope everyone had a nice weekend. In absence of being able to attach the front baffles to the four custom sub boxes, I made some progress this weekend by filling all the screw / nail holes and sanding smooth most of the 8 subwoofer boxes. I created a little bit of a hot mess when I used a belt sander to take off the lip on one of the 24" sub boxes, creating some sanding gouges which will have to be flattened, filled and sanded to correct. No big deal, just an extra step. Pics of this later this week.

In the meantime I thought I'd try to catch up this thread with the BHS-24 box build before the pics got too old. These pics are from over a week ago.

Since these front baffles were 3" thick, the plan called for additional fixation with screws coming from the back side of the inner baffle layer. Because CNC'ing these screw holes would have taken a bit change and another hour or so of machine time, we skipped this step in favor of me going back and manually adding in the screws. Using a blown up picture of the CAD file as reference, I laid out all the screw locations.


I also laid out the intended handle locations.


I pre-installed all the screws so I could fly through the attachment process once the glue was applied to the other side.


To make sure the handle locations were accurate through both baffle pieces, I temporarily clamped the baffles together and drilled a pilot hole all the way through both baffle pieces.


To install the threaded inserts used for the handles, I had a 9mm bit for the threaded insert, 1/4" bit for the hex bolt diameter, a hex driver and a 9/16" paddle bit to create a slight lip for the threaded insert. Gorilla Super Glue was used in the hole and along the threads of the insert as extra insurance to permanently lock it into position.


Here was my process. First, I used a 9/16" paddle bit to create a slight recess for the lip of the insert so the baffle pieces would lay flat when glued together.


Here you can see this slight recess in action (with the insert turned upside down)


Not pictured, but I then drilled down the depth of the insert with my 9mm bit and then all the way through the baffle using the 1/4" drill bit. CA glue was applied to the inside of the hole with an artist's brush and again over the threads of the insert. Here's the final result, just before installing the inserts.


The 2" Hex bolts would extend into the inner baffle layer, even with the thickness of the metal handle and washers. I used the 1/4" drill bit to drill down approximately 1/2" to accommodate the other end of the bolt passing through the threaded insert.


I installed all the threaded inserts for the handles and the subwoofer driver and was finally ready to apply the glue.


I applied a generous amount of glue to one side of one baffle layer, anticipating the glue to 'soak in' to its adjoining layer. In other words, I applied enough glue for both layers on this one glue-up and let it soak in for a few minutes before binding together.


No pics of the actual alignment, clamping, glue squeeze out, etc. because you really had to hustle to get everything locked down during the working time, but I noticed during the clamp-up I was getting big puddles of glue on my work table. I'm not sure why I didn't think of it, but some of the squeeze out was coming through the threaded inserts for the handles.


Petrified the holes were going to fill with hardened glue and be unusable, I immediately lifted this huge, clamped mass onto its side and cleaned out the holes the best I could and immediately ran the hex bolts into position. I kept turning these bolts every 5-10 minutes for the next four hours so they wouldn't get glued in one location.


Here you can see the handle bolts installed.


And the really nice squeeze-out I was able to get, especially around the future driver mounting location.


I returned the front baffle to flat with all the clamps and added some weight in the middle.


Rinse and repeat for the second front baffle. Mapped out all the screw fixation and handle locations and installed the threaded inserts...


Generous amount of glue applied...


Here you can see the full thickness of these front baffles when bound together




Finished front baffles


With the baffles complete, I turned my attention to coating every single inside corner in both boxes with a heavy layer of PL Premium to further bind everything together.




So that was it for the two front baffles. I'd like to get to the point of permanently attaching them to the boxes sometime next weekend once all the clamps I am able to borrow are back in-hand.
Attached Thumbnails
Click image for larger version

Name:	010 Ready for glue.jpg
Views:	205
Size:	752.6 KB
ID:	2475102   Click image for larger version

Name:	009 Hex Bolt.jpg
Views:	204
Size:	695.9 KB
ID:	2475104   Click image for larger version

Name:	008 Four finished holes.jpg
Views:	198
Size:	754.6 KB
ID:	2475106   Click image for larger version

Name:	007 Spade bit.jpg
Views:	198
Size:	636.8 KB
ID:	2475108   Click image for larger version

Name:	006 Spade Bit.jpg
Views:	201
Size:	701.3 KB
ID:	2475110  

Click image for larger version

Name:	005 Threaded Insert tools.jpg
Views:	196
Size:	671.0 KB
ID:	2475112   Click image for larger version

Name:	004 Positioning both layers for handles.jpg
Views:	296
Size:	773.9 KB
ID:	2475114   Click image for larger version

Name:	003 Screws preinstalled.jpg
Views:	196
Size:	981.0 KB
ID:	2475116   Click image for larger version

Name:	002 Handle Layout.jpg
Views:	195
Size:	940.5 KB
ID:	2475118   Click image for larger version

Name:	001 Screw Layout.jpg
Views:	194
Size:	888.5 KB
ID:	2475120  

Click image for larger version

Name:	018 Second baffle glue up.jpg
Views:	194
Size:	846.2 KB
ID:	2475122   Click image for larger version

Name:	017 Threaded Inserts.jpg
Views:	189
Size:	645.3 KB
ID:	2475124   Click image for larger version

Name:	016 Clamp and weight.jpg
Views:	197
Size:	923.2 KB
ID:	2475126   Click image for larger version

Name:	015 Squeeze out.jpg
Views:	198
Size:	873.0 KB
ID:	2475128   Click image for larger version

Name:	014 Handle bolts installed.jpg
Views:	195
Size:	755.9 KB
ID:	2475130  

Click image for larger version

Name:	013 Install hex bolts.jpg
Views:	194
Size:	786.5 KB
ID:	2475132   Click image for larger version

Name:	012 Glue leaking.jpg
Views:	201
Size:	890.9 KB
ID:	2475134   Click image for larger version

Name:	011 Glue Applied.jpg
Views:	194
Size:	590.6 KB
ID:	2475136   Click image for larger version

Name:	023 Bracing Glue.jpg
Views:	192
Size:	850.8 KB
ID:	2475138   Click image for larger version

Name:	022 Bracking glue.jpg
Views:	198
Size:	823.1 KB
ID:	2475140  

Click image for larger version

Name:	021 Finished baffles.jpg
Views:	195
Size:	877.2 KB
ID:	2475142   Click image for larger version

Name:	020 Baffle Thickness.jpg
Views:	203
Size:	754.1 KB
ID:	2475144   Click image for larger version

Name:	019 Baffle Thickness.jpg
Views:	194
Size:	939.6 KB
ID:	2475146  
mikela, J_P_A, OJ Bartley and 1 others like this.
TMcG is offline  
post #2568 of 3160 Old 10-29-2018, 06:50 AM
Senior Member
 
Join Date: Mar 2017
Location: Birmingham,Alabama
Posts: 294
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 135 Post(s)
Liked: 172
Quote:
In the meantime I thought I'd try to catch up this thread with the BHS-24 box build
Perfectly executed. Unless one has attempted to laminate two large pieces of sheet good together it's hard to realize just how difficult it can become if not handled well - or just how easily you can have a de-lamination later on down the road if you haven't gotten the clamping force to the center of the panel. There will be no such problems here - I doubt there would be even without the screws but with them it would take a jackhammer to get those panels apart. Well done on the boxes sir.
TMcG likes this.
p3bham is offline  
post #2569 of 3160 Old 10-29-2018, 07:50 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by p3bham View Post
Perfectly executed. Unless one has attempted to laminate two large pieces of sheet good together it's hard to realize just how difficult it can become if not handled well - or just how easily you can have a de-lamination later on down the road if you haven't gotten the clamping force to the center of the panel. There will be no such problems here - I doubt there would be even without the screws but with them it would take a jackhammer to get those panels apart. Well done on the boxes sir.
Thanks! This was my very first time gluing two big sheets together. I wasn't prepared for how difficult it was to get the two pieces to line up perfectly and their tendency to "float" around. It took a solid 5-8 minutes just to align the panels and get the initial clamps secured as the simple act of tightening the clamps would throw everything off. Thank goodness for the 0.5mm pencil reference marks I had scattered around the perimeter and the driver hole before glue to KNOW everything was lined up properly before the first screw was driven.

I didn't bother taking pictures of it, but after building the first baffle I made a right angle from straight 2x4 scrap secured to my work bench so I could push the two pieces diagonally into the corner of these right angle pieces to simplify the panel alignment process. Because of this, the second baffle went much more quickly and was lined up a bit better than the first. Being my first time ever doing such a large panel glue-up, I didn't predict the movement of the panels on the glue layer. Lesson learned and I made my life easier for the second glue-up.
TMcG is offline  
post #2570 of 3160 Old 10-29-2018, 08:09 AM
AVS Forum Special Member
 
OJ Bartley's Avatar
 
Join Date: Apr 2009
Location: Toronto, ON
Posts: 1,189
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 496 Post(s)
Liked: 589
Quote:
Originally Posted by TMcG View Post
Very well executed. And happy Halloween! lol

OJ Bartley is offline  
post #2571 of 3160 Old 10-29-2018, 09:21 AM
AVS Forum Special Member
 
dkersten's Avatar
 
Join Date: Oct 2013
Location: Billings, MT
Posts: 1,130
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
Quoted: 703 Post(s)
Liked: 1229
I have built hundreds upon hundreds of subwoofer enclosures over the years and here are a couple pieces of my personal experience:

Poly, dacron, or whatever fill you use is for damping characteristics, and I would NEVER build a sub box without filling it with some kind of damping material. It does help with internal resonances, which will happen no matter what shape you have internally, but that is just one reason to add it, the other is to improve damping, which I have always felt is important in a subwoofer.

Use your batting sheets to "net" the poly fill in place. I staple it around the subwoofer opening and to braces behind the sub so the fill doesn't shift and end up inside the basket of the sub and end up resting on the back side of the cone. If you have a ported enclosure, you can likewise "net" around the port opening to keep some void a few inches around that port. No need to search for anything more, you already have what you need in that 1" batting. In fact, I used to use 2" dacron batting for all my boxes, I prefered it over polyfill as it retained its shape and stayed where I put it.

As for construction, I have always preferred wood glue and brad nails, with a silicone caulk on all inside corners to seal it up air tight.

Be generous with the wood glue, you can always wipe the excess away.
Brad nails will secure it in place and then clamps are no longer a requirement. I rarely need to clamp anything having to do with MDF. Granted, if you are dealing with a finished surface and don't want to fill brad nail holes, then glue and clamp is perfectly fine, just slower. If this were solid hardwood, your methods are exactly what I would do, but for MDF, even if I am going to veneer it, I brad nail it to hold it securely in place until the glue dries. Never underestimate the clamping power of a few brad nails.

I personally wouldn't use the PL (or any brand) liquid nails to seal the inside corners. PL does make an EXCEPTIONAL silicone rubber alternative caulk that I will now use exclusively. Liquid Nails was never designed to make a seam air and water tight, it is just a construction glue. I realize it is popular here, and I am just saying I wouldn't use it for the purpose of sealing up a joint. Pure Silicone or the PL alternative for me. Just keep in mind, Silicone is NOT a replacement for wood glue.

On big boxes, the final side is always a challenge as you can't reach in through the speaker hole to caulk the remaining seams, so for those I run a bead of wood glue on the middle of the wood edge, and a bead of silicone on the inside corner, just a couple millimeters onto the edge. That way when the last piece goes on, the wood glue will glue the piece on permanently and the silicone will seal it air tight.

I have never had an MDF box that was glued and brad nailed together come apart, even under the most extreme circumstances. In fact, when I had to dismantle my boxes I always resorted to sledge hammers and reciprocating saws. That is with almost never using a clamp.

Great work, as always. Overkill is never a bad thing, as long as you can engineer it all to fit together.
TMcG likes this.
dkersten is offline  
post #2572 of 3160 Old 10-29-2018, 10:43 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by OJ Bartley View Post
Funny enough, I texted Mike Fusick this photo and said I was creating my own Pinhead costume. Great minds think alike!


Quote:
Originally Posted by dkersten View Post
1. Use your batting sheets to "net" the poly fill in place.

2. As for construction, I have always preferred wood glue and brad nails, with a silicone caulk on all inside corners to seal it up air tight....Brad nails will secure it in place and then clamps are no longer a requirement. Never underestimate the clamping power of a few brad nails.

3. Be generous with the wood glue, you can always wipe the excess away.

4. I personally wouldn't use the PL (or any brand) liquid nails to seal the inside corners...was never designed to make a seam air and water tight, it is just a construction glue.

5. On big boxes, the final side is always a challenge as you can't reach in through the speaker hole to caulk the remaining seams, so for those I run a bead of wood glue on the middle of the wood edge, and a bead of silicone on the inside corner, just a couple millimeters onto the edge. That way when the last piece goes on, the wood glue will glue the piece on permanently and the silicone will seal it air tight.
Thanks for all the feedback! I didn't realize you were such an experienced box builder. Sorry for the cringeworthy box build procedures...as I said...I'm a noob and these are my first boxes ever.

To take your suggestions one at a time...(I added numbering to each for convenience)

1. Great idea to use the poly batting to hold the fill into position around the driver. Unfortunately I already bought some nylon mesh at Joann Fabrics this past weekend, so I'll use it since it is non-returnable.

2. I used a few brads on the 3/4" MDF boxes after everything was clamped and I was happy with the fit and positioning of each piece. I primarily used glue and clamps with brad nails functioning as a temporary hold more than something intended to hold while the glue cured. Plus brads could not be used for this 1.5" thick material, even with the longest available brad nails (which my gun wouldn't hold). Using brads on the 3/4" MDF box for the 18" sub drivers was no problem.

3. I've been more than generous with the glue, giving both surfaces a nice uniform coat before clamping together. Used a ton of paper towels and damp rags to clean up the squeeze out. I've used nearly 1.5 gallons of Titebond III for this glue-up so far!!!

4. I used the adhesive as a reinforcing bond, not a sealant. I'm sure silicone would provide some sheer resistance, but not as much as the cured adhesive. In my mind it was just one more thing to add strength and rigidity to the box.

5. Makes perfect sense and is exactly what I plan to do....with the exception of PL Premium instead of silicone on the edges of the bracing.
TMcG is offline  
post #2573 of 3160 Old 10-29-2018, 11:00 AM
AVS Forum Special Member
 
dkersten's Avatar
 
Join Date: Oct 2013
Location: Billings, MT
Posts: 1,130
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
Quoted: 703 Post(s)
Liked: 1229
I was a professional car audio installer for about a decade, so that is where my box building experience came from. Since 2000 I have probably built fewer than 50 various speaker enclosures, but in the decade before, figure roughly one per week on average for nearly 10 years. That's a lot of sub boxes, lol.

Quote:
Originally Posted by TMcG View Post
3. I've been more than generous with the glue, giving both surfaces a nice uniform coat before clamping together. Used a ton of paper towels and damp rags to clean up the squeeze out. I've used nearly 1.5 gallons of Titebond III for this glue-up so far!!!
That's a lot of glue! I went through about 1 of the med sized titebond II bottles for my 6 sub enclosures. I like titebond 2 as it has a faster cure time, I think 3 is for outdoor uses isn't it?

Quote:
4. I used the adhesive as a reinforcing bond, not a sealant. I'm sure silicone would provide some sheer resistance, but not as much as the cured adhesive. In my mind it was just one more thing to add strength and rigidity to the box.
Nothing wrong with this, although I would say if the wood glue wasn't enough to hold the braces in place then the rest is just a bandaid. Like I said though, nothing wrong with overkill.

On any of the outside box seams, you should seal up the inside corner with silicone or the PL equivalent. Regular wood glue will shrink when it dries and leave air gaps. On a sealed box in particular, any air gaps are bad. Even on a ported box you want the box itself to be air tight, which doesn't seem to make much sense since it has a big hole it in. Big air gaps will whistle, little ones will likely go unnoticed but will change the tuning ever so slightly, and affect the overall power handling of the driver.

Again, just my opinions, I am sure some would disagree with me.
dkersten is offline  
post #2574 of 3160 Old 10-29-2018, 12:04 PM
AVS Forum Addicted Member
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 14,557
Mentioned: 400 Post(s)
Tagged: 1 Thread(s)
Quoted: 5622 Post(s)
Liked: 5459
Quote:
Originally Posted by dkersten View Post
I was a professional car audio installer for about a decade, so that is where my box building experience came from. Since 2000 I have probably built fewer than 50 various speaker enclosures, but in the decade before, figure roughly one per week on average for nearly 10 years. That's a lot of sub boxes, lol.


That's a lot of glue! I went through about 1 of the med sized titebond II bottles for my 6 sub enclosures. I like titebond 2 as it has a faster cure time, I think 3 is for outdoor uses isn't it?


Nothing wrong with this, although I would say if the wood glue wasn't enough to hold the braces in place then the rest is just a bandaid. Like I said though, nothing wrong with overkill.

On any of the outside box seams, you should seal up the inside corner with silicone or the PL equivalent. Regular wood glue will shrink when it dries and leave air gaps. On a sealed box in particular, any air gaps are bad. Even on a ported box you want the box itself to be air tight, which doesn't seem to make much sense since it has a big hole it in. Big air gaps will whistle, little ones will likely go unnoticed but will change the tuning ever so slightly, and affect the overall power handling of the driver.

Again, just my opinions, I am sure some would disagree with me.
Pretty spot on from my experience. I did as of the last few builds start using silicone in the seams as well, but that was purely due to having some on-hand as opposed to PL who's expansive properties are actually pretty good if you spot a 1/4" bead just inside the joining surface as you described. Out of at least a dozen boxes done that way I never had a problem, just FWIW.

European Models do not accept banana plugs
Belly of the Beast: Bass Bunker Theater
beastaudio is offline  
post #2575 of 3160 Old 10-30-2018, 03:33 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by dkersten View Post
That's a lot of glue! I went through about 1 of the med sized titebond II bottles for my 6 sub enclosures. I like titebond 2 as it has a faster cure time, I think 3 is for outdoor uses isn't it?

Again, just my opinions, I am sure some would disagree with me.
I love it when experienced pros bring the knowledge, so keep it coming whenever you see me making a mistake!

Titebond III is for both indoor and outdoor. I chose it because it has a slightly longer open and cure time to help me get through the glue-ups without the adhesive skinning over, but more importantly it has the highest bonding strength of any of their glues.
TMcG is offline  
post #2576 of 3160 Old 10-30-2018, 04:19 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Custom IST UXL-18 Box Build

This is the last of the subwoofer build pictures to catch you up to date. These are the rear subwoofers which I had custom designed into a 4 cubic foot enclosure but with the most shallow depth possible to fit within the double rear walls of my theater.

A couple angles of the box as-drawn in CAD. Material is 3/4" MDF for the box and 13-ply Baltic Birch for the matrix bracing.




Reinforcing strips for the bottom feet as the depth of the threaded insert extends beyond the depth of the 3/4" MDF used for the box.


Securing the bracing precisely within the dados was more of a challenge than I expected. After gluing the bracing into the dados, I added the side panels and clamped so the left-to-right alignment of these brace pieces would be precise. A tiny bit of the glue squeeze out "attached" the side panels, but nothing I couldn't overcome with a few light hammer blows and scrape off with my chisel. While clamped I added SPAX MDF screws through the back into the 'meat' of each brace piece to keep the bracing very secure.


I found it easier to add both side panels at once, so both sides were glued and clamped at the same time.


Test fit for the top and bottom. I didn't want to glue them in place until I had the chance to replicate them on my table saw for the second box due to the CNC mis-cut.


There were some challenges with the CNC'd parts for these boxes as well. The wrong bit size was programmed into the machine so the ends of the side pieces had these little spots which needed removed.


Plus there was movement of cut pieces which created little nubs which needed to be removed. All miscuts were easily addressed with my oscillating saw, chisel and sander.


Gluing up the second box


And finally it was time to bond the front baffle pieces together. I gave a somewhat generous coat of glue only to one side then flipped it onto its mating piece and allowed the glue to 'soak in' to the non-glued piece for a few minutes before attaching and clamping


I used virtually all the clamps. To get extra pressure in the middle of the baffle I used 2x4s on edge to transfer the clamping pressure. Seemed to work.


Another angle of the clamp-up


Lather, rinse and repeat for the second baflle...


Both boxes 'done' (as of 10 days ago before I cut the replacement pieces)


Since the time of these pictures I've since made the replacement pieces and attached all the tops and bottoms to both boxes. I've also ran a bead of PL Premium glue around all inside corners and thoroughly sanded the boxes smooth up to 150 grit after filling all the screw and brad nail holes. Only remaining tasks are adding the polyfill, attaching the front baffle (and sanding smooth after the glue is dry), and adding the sub driver threaded inserts.

I will wire and paint (months) later as I only wanted to get these boxes built and the driver installed so all the parts, pieces and equipment was 'used up' and easy to store and get out of my way. If you recall the pictures from last February, the cut wood from all these custom boxes completely filled my SUV. It's a lot of 'stuff'. And this didn't even include the pile of DIY Soundgroup boxes which I also wanted to build and install the driver vs. shifting all the pieces back and forth out of my way.

Quick update....
  • I'm able to re-borrow all of my neighbor's clamps on Thursday night, so it's my goal to attach all the front baffles and be completely finished (for now) with all 8 sub boxes by Sunday night. I think it's doable, given where the project stands right now.
  • On the horizon is an update to the basement wiring, my equipment rack cooling plan and maybe a few updated renderings. I still have to update the planned equipment list in my first post!!
Attached Thumbnails
Click image for larger version

Name:	uxl-2.JPG
Views:	260
Size:	125.3 KB
ID:	2475560   Click image for larger version

Name:	tim uxl.JPG
Views:	258
Size:	102.4 KB
ID:	2475562   Click image for larger version

Name:	strips.JPG
Views:	260
Size:	92.1 KB
ID:	2475564   Click image for larger version

Name:	IMG_5174.jpg
Views:	268
Size:	929.9 KB
ID:	2475566   Click image for larger version

Name:	IMG_5181.jpg
Views:	270
Size:	1,012.8 KB
ID:	2475568  

Click image for larger version

Name:	IMG_5182.jpg
Views:	258
Size:	744.7 KB
ID:	2475570   Click image for larger version

Name:	IMG_5185.jpg
Views:	260
Size:	590.1 KB
ID:	2475572   Click image for larger version

Name:	IMG_5184.jpg
Views:	262
Size:	682.8 KB
ID:	2475574   Click image for larger version

Name:	IMG_5186.jpg
Views:	258
Size:	828.4 KB
ID:	2475576   Click image for larger version

Name:	IMG_5224.jpg
Views:	265
Size:	809.4 KB
ID:	2475578  

Click image for larger version

Name:	IMG_5225.jpg
Views:	274
Size:	990.4 KB
ID:	2475580   Click image for larger version

Name:	IMG_5228.jpg
Views:	261
Size:	1,008.5 KB
ID:	2475582   Click image for larger version

Name:	IMG_5238.jpg
Views:	266
Size:	847.4 KB
ID:	2475584   Click image for larger version

Name:	IMG_5239.jpg
Views:	268
Size:	812.0 KB
ID:	2475586  
OJ Bartley likes this.

Last edited by TMcG; 10-30-2018 at 04:32 AM.
TMcG is offline  
post #2577 of 3160 Old 10-30-2018, 07:02 AM
Senior Member
 
Join Date: Mar 2017
Location: Birmingham,Alabama
Posts: 294
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 135 Post(s)
Liked: 172
Quote:
Thanks! This was my very first time gluing two big sheets together. I wasn't prepared for how difficult it was to get the two pieces to line up perfectly and their tendency to "float" around. It took a solid 5-8 minutes just to align the panels and get the initial clamps secured as the simple act of tightening the clamps would throw everything off. Thank goodness for the 0.5mm pencil reference marks I had scattered around the perimeter and the driver hole before glue to KNOW everything was lined up properly before the first screw was driven.
Yep. That tendency to float around is exactly what I meant. If you don't have the means to make a jig then often you can let the glue begin to "tack up" a bit and that will help with the slipping. But...

Quote:
I didn't bother taking pictures of it, but after building the first baffle I made a right angle from straight 2x4 scrap secured to my work bench so I could push the two pieces diagonally into the corner of these right angle pieces to simplify the panel alignment process. Because of this, the second baffle went much more quickly and was lined up a bit better than the first. Being my first time ever doing such a large panel glue-up, I didn't predict the movement of the panels on the glue layer. Lesson learned and I made my life easier for the second glue-up.
This is a great way to go. Before I had my new assembly table system (3" thick 4'x8' birch ply with 3/4" holes drilled by CNC on 3" centers so I can use various clamping jigs) I had all sorts of jigs around the shop to do various tasks - probably the most used of which was a simple 90 degree jig like you made. Makes life much easier.

As to the whole to clamp or not to clamp issue mentioned above, I fall into the always clamp category. That being said it IS probable that the weight of the MDF combined with it's flatness will provide proper contact to not worry about clamping. But old habits die hard and since I'm not likely to be in a production situation with panel lamination I like the extra security clamping provides despite it taking longer - particularly in the middle of panels. The main reason is I have seen both MDF and even Birch plywood have warp in them - and clamping them the way you did with cauls across the panel ensures that there are no unjoined spaces in the middle of the panel. I am in general a "overkill is just barely enough" person when it comes to building projects such as these. I'm sure those that have built hundreds of speaker boxes above know exactly what they're doing and I'm not at all saying they don't - just that I always prefer clamps to brads. Where I will often use a brad is at the start of joining two panels. I will apply glue and put the two together, making sure everything is perfectly aligned. I'll then use a pin nail or brad to tack one pair of diagonal corners before I start adding clamps. And it's this that convinces me completely that clamping is better - no matter how hard you push down when you shoot those initial brads/pins in, when you clamp there is always more squeeze out - which says to me that the brads aren't pulling the panels as tight together as the clamps do. Just my two cents.

Quote:
Titebond III is for both indoor and outdoor. I chose it because it has a slightly longer open and cure time to help me get through the glue-ups without the adhesive skinning over, but more importantly it has the highest bonding strength of any of their glues.
By far my favorite and the only wood glue I use except on rare occasions where I use hide glue to keep the integrity of an antique during restoration (hide glue is as bad as it sounds) or when I use the Titebond Extend for big glue ups.

Quote:
This is the last of the subwoofer build pictures to catch you up to date. These are the rear subwoofers which I had custom designed into a 4 cubic foot enclosure but with the most shallow depth possible to fit within the double rear walls of my theater.
These things are going to be absolutely epic.
TMcG likes this.

Roll Tide.
p3bham is offline  
post #2578 of 3160 Old 10-30-2018, 08:51 AM
AVS Forum Addicted Member
 
beastaudio's Avatar
 
Join Date: Dec 2010
Location: Western NC
Posts: 14,557
Mentioned: 400 Post(s)
Tagged: 1 Thread(s)
Quoted: 5622 Post(s)
Liked: 5459
Wait, so two 24's up front, two 18" rear subs and then where is the plan to put the other 4 DIYSG cubes?
ereed likes this.

European Models do not accept banana plugs
Belly of the Beast: Bass Bunker Theater
beastaudio is offline  
post #2579 of 3160 Old 10-30-2018, 09:46 AM
AVS Forum Special Member
 
OJ Bartley's Avatar
 
Join Date: Apr 2009
Location: Toronto, ON
Posts: 1,189
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 496 Post(s)
Liked: 589
I agree with p3bham, the LFE levels in your room are going to be completely epic. A pair of 24s, a couple of nearfield UXL-18's AND 4 more... wow.
OJ Bartley is offline  
post #2580 of 3160 Old 10-31-2018, 06:05 AM - Thread Starter
AVS Forum Special Member
 
TMcG's Avatar
 
Join Date: Mar 2010
Location: Earth
Posts: 4,710
Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1648 Post(s)
Liked: 1890
Quote:
Originally Posted by p3bham View Post
I always prefer clamps to brads. Where I will often use a brad is at the start of joining two panels. I will apply glue and put the two together, making sure everything is perfectly aligned. I'll then use a pin nail or brad to tack one pair of diagonal corners before I start adding clamps. And it's this that convinces me completely that clamping is better - no matter how hard you push down when you shoot those initial brads/pins in, when you clamp there is always more squeeze out - which says to me that the brads aren't pulling the panels as tight together as the clamps do. Just my two cents.
Totally agree. In fact, I ended up using a minimum of brads exactly in the fashion you described above. And by the way, I didn't even know what "cauls" were...I thought I invented my own little way of applying pressure where you couldn't get clamps without it being just raw weight piled on top.

Quote:
Originally Posted by beastaudio View Post
Wait, so two 24's up front, two 18" rear subs and then where is the plan to put the other 4 DIYSG cubes?
The original plan was four 18s, one in each corner. Then I stumbled on a deal for the pair of 24s and was going to sell off one pair of 18s. A quick discussion with Adam Pelz changed that. The four 18s are still going to be in the four corners, but the two 24s will flank either side of the center channel speaker. The 18s will handle the majority of the LFE down to 20-25 (ish) Hz and the 24s will be crossed over to slaughter anything less than 25Hz, backed by 4400 watts per sub. I have two extra 18" sub boxes and no drivers to fill them. I considered getting two more 18s so the front 18s would be double stacked. It's all about the overhead, right?

Quote:
Originally Posted by OJ Bartley View Post
I agree with p3bham, the LFE levels in your room are going to be completely epic. A pair of 24s, a couple of nearfield UXL-18's AND 4 more... wow.
Technically the rear 18s aren't nearfield...they are the four primary LFE subs, one in each corner. The rear subs are slightly inset from the corners because of a steel column I had to avoid in the back left of the room. I could put the back right sub all the way into the corner, but decided to make it equal in distance from the corner as the rear left sub.
TMcG is offline  
Sponsored Links
Advertisement
 
Reply Dedicated Theater Design & Construction

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off