AVS › AVS Forum › Audio › DIY Speakers and Subs › Dimensions for sealed 18" sub box
New Posts  All Forums:Forum Nav:

Dimensions for sealed 18" sub box - Page 4

post #91 of 679
4/25/12 at 5:49am
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

"The LMS is nearly 12" deep, and you can't put a brace directly behind the magnet because I'm sure there's a vent back there. So if you move the brace 3" off the back of the LMS, you now have one stick brace dividing a panel into 15" x 23" and 5" x 23". I think a 15" x 23" panel would need extra bracing?"

roger and considered that. that is why i put in the angled cut in the cutplan. plenty of spacing between the brace that i suggested and the drive.

in this concept, there is no 'stick' bracing.

the gray area is the removed material. the white panel on the right can be rotated 90 bottom toward you, then 180 degrees to the left and will slide into the other panel for a simple effective fit/brace.

if the design has been finalized, that's cool.

i thought this was a design thread, hence my comments...


There will be different designs. The Baltic birch cabinets will likely have bracing like we discussed in that thread last year. It's similar to what you drew out, but it adds a little more.

I promise, I've been working on about 20 different bracing ideas. It's been discussed here for years and I do realize what's needed and what is considered overkill. but for the general public, it has to also look impressive or I will be stuck with a lot of boxes. It also must be able to be assembled by a 12 yr old.

I'll get the photo up of the other bracing we all tweaked last year.
Reply
Reply

AVS Top Picks

post #92 of 679
4/25/12 at 8:36am
Great looking boxes, personally I think the bracing is overkill, but like you said it's been discussed before. I am interested in the weight factor when using all that material for bracing though. For example I live on the west coast and as Erich knows it's not cheap to ship out here. So if all that bracing adds several pounds to the design it becomes cheaper for someone like myself who has the means to make his own boxes. Also has a structural engineer looked at the bracing on these things, I mean can a 3/4" panel flex enough to make it necessary to brace every 12" or whatever it may be? I understand that it has to look impressive, but that becomes moot once the baffle goes on, so unless it's scientifically proven otherwise I'll say the reasoning for all that bracing is strictly aesthetic.
Reply
Reply
post #93 of 679
4/25/12 at 11:12am
I like the way the last box (smallest) is done for the face. It covers the top and bottom mdf with just a sliver on the sides.


Quote:
Originally Posted by Erich H View Post

Bracing divides all panels up around 6" and everything locks together and slides in from the front if that's how you wanted to assemble them.



Keep in mind, this following picture doesn't show the outer baffles, only the first layer dropped in flush. You can see how each box was done differently for experimenting. The final method is the box on the left. Obviously these boxes are only held together with tape. Actually, the inner baffle is just sitting inside the box without tape, so it might look a little lose. It's not once you squeeze the sides together with your hands.....or glue.







To be honest, I liked how easy the first baffle installed on the smaller box. It looks better here, but it doesn't matter because all will be covered up with the outer baffle anyway.

The only reason I didn't like the 10" method was because from above, you would see the seam of that baffle, and the seam for the outer one as well.

Then you can see the progression to the 12" model where it dropped in, but only rabbets were cut on the side panels. At that point, I saw no reason why rabbet joints should just be cut all the way around.
Reply
Reply
post #94 of 679
4/25/12 at 11:22am
sepen, there will be full front baffles that extend edge to edge that go on top of the images in the pic.
Reply
Reply
post #95 of 679
4/25/12 at 11:30am
Ahhhhh, thanks for that info.


Quote:
Originally Posted by LTD02 View Post

sepen, there will be full front baffles that extend edge to edge that go on top of the images in the pic.
Reply
Reply
post #96 of 679
4/25/12 at 11:59am
no worries, for every question asked there are at least ten folks who were wondering the same thing.
Reply
Reply
post #97 of 679
4/26/12 at 7:06am
Thread Starter 
Quote:
Originally Posted by LTD02 View Post


in this concept, there is no 'stick' bracing.

the gray area is the removed material. the white panel on the right can be rotated 90 bottom toward you, then 180 degrees to the left and will slide into the other panel for a simple effective fit/brace.

if the design has been finalized, that's cool.

i thought this was a design thread, hence my comments...

LTD02,

I'm looking at your bracing idea again (attached below). Similar designs were discussed last year in the bracing thread and your design is fairly similar to what was discussed then. So I do understand how you've got it going together.

But going by the photo there would be panels 12" x 20" and about 10" x 23" with no bracing throughout the box. I don't doubt that's okay, but going by what I always see DIY guys do, I'm not sure it will be enough for them. What do you think?

My design is essentially the same as yours, it just adds an extra vertical and horizontal brace to divide the cabinet up into smaller pieces. That also keeps any brace from being directly behind the rear vent.
LL
Reply
Reply
post #98 of 679
4/26/12 at 8:59am
designing to what folks perceive vs. what actually matters is a really good point that i hadn't really considered.

your design definitely has the "big beefy overkill" look to it that many folks will like.

i really don't have a good sense for where the price breaking point would be for folks on something like this. i suppose in the context of the total price of the project (driver, enclosure, eq, amp, etc.), the little extra money for what you have is probably the way most customers would tilt. at least on this morning, i say proceed with what you have.

the engineer in me just has such a difficult time with that decision, but sometimes you have to tell the engineer to be quiet. :-)
Reply
Reply
post #99 of 679
4/26/12 at 8:56pm
Thread Starter 
Photos of the 18" sealed box:



Notice that the shelf bracing does go along the rear panel. They're on all the boxes, but the shadows sometimes hide them.


I must have left one of the optional braces at the CNC company. Some of these big 18" drivers are really deep, so the cross braces need to be pushed back further in the box to avoid the rear of the magnet. So I thought of a neat idea to solve that problem. Notice the shelf "tabs" cut into each brace. An optional brace shaped like an octagon can easily be glued directly to those that would also stiffen up the front portion of the enclosure. I realize it's not needed, but might be an option to anyone that really wanted to go nuts.



Here's the 18" sealed box next to the 15" sealed box:


Reply
Reply
post #100 of 679
4/26/12 at 9:00pm
Quote:
Originally Posted by Erich H View Post

Photos of the 18" sealed box:



Notice that the shelf bracing does go along the rear panel.


I must have left one of the optional braces at the CNC company. Some of these big 18" drivers are really deep, so the cross braces need to be pushed back further in the box to avoid the rear of the magnet. So I thought of a neat idea to solve that problem. Notice the shelf "tabs" cut into each brace. An optional brace shaped like an octagon can easily be glued directly to those that would also stiffen up the front portion of the enclosure. I realize it's not needed, but might be an option to anyone that really wanted to go nuts.



Here's the 18" sealed box next to the 15" sealed box:



does that mean that you actually have a optional brace made up already? my credit cards are ready!
Reply
Reply
post #101 of 679
4/26/12 at 9:18pm
Thread Starter 
I think it might be better to figure these as sealed enclosures and just make some slightly different boxes for any ported design you guys might want. I do think a couple of these could be used for a ported box with no problem though.

Keep in mind, the following picture does not show the front baffle that covers up all the seams.




The smallest sealed box is 14" x 15" x 16" deep with a double thick baffle. It nets around 1.25 cu ft. I figure it could be used for most 10's and some 12's. Bracing does go along the rear panel, but it can easily be cut out for plate amp installation.


Next up is a sealed box 16" wide x 19" tall x 18" deep with a double baffle. Notice an extra horizontal brace. Net volume is around 2.25 cu ft. Good size for many sealed 12's, some ported 10's? This is plate amp installation friendly.


Stepping up to the bigger boxes. 18" wide x 23" tall x 20" deep with a double baffle. This size gets 2 vertical and 2 horizontal braces. Not volume comes in around 3.5 cu ft which should be great for sealed 15's and some ported 12's. Again, installing a plate amp will be easy.


The box for the 18" was going to be 22" wide, and it still can be. But I went ahead and had them make it 23" wide x 23" tall x 20" deep and of course with a double baffle. There's an optional brace that can be used to tie in the front portion of the box even more than the previous photo showed. This box is not as plate amplifier friendly because I figured most people would be using pro amps. I can always get them to change one of the shelf braces to allow for an easier plate amp to be installed if needed. Anyway, this box nets a very nice 4.5 cu ft. If we decide on 22" wide, that would drop to a little more than 4.25 cu ft after we subtract off bracing volume.




If anyone can think of a different size or shape that might make sense, please let me know. I'm not the best at modeling subwoofers so if anyone would like to see a ported design for a specific driver, I'll do my best to get things rolling.

If anyone would like to make suggestions on some very common models that should have a specific enclosure......sealed or ported......I'll see what I can do.
Reply
Reply
post #102 of 679
4/26/12 at 9:22pm
Thread Starter 
Quote:
Originally Posted by ufokillerz View Post

does that mean that you actually have a optional brace made up already? my credit cards are ready!

Yeh, the brace sits right on those "shelves" that were cut about 6" down into the box. I'll get a photo of the brace installed shortly.

I'm suppose to meet with them again on Saturday if I'm caught up at work. (who knows)

I'd like to look into ported boxes if anyone has any specific ideas.
Reply
Reply
post #103 of 679
4/27/12 at 6:15am
every time i see someone posts in this thread all i can think is ..
LL
Reply
Reply
post #104 of 679
4/27/12 at 12:20pm
I like the look/size of the smallest one. I wonder how having 2 of these running a Dayton 12" HF or HO would perform?
Reply
Reply
post #105 of 679
4/27/12 at 1:36pm
Quote:
Originally Posted by Sibuna View Post

every time i see someone posts in this thread all i can think is ..

Same here. I have two spare MFW-15 drivers and two bash 300 amps anxiously waiting for boxes...
Reply
Reply
post #106 of 679
4/27/12 at 2:40pm
Quote:
Originally Posted by Erich H View Post

I think it might be better to figure these as sealed enclosures and just make some slightly different boxes for any ported design you guys might want. I do think a couple of these could be used for a ported box with no problem though.

Keep in mind, the following picture does not show the front baffle that covers up all the seams.




The smallest sealed box is 14" x 15" x 16" deep with a double thick baffle. It nets around 1.25 cu ft. I figure it could be used for most 10's and some 12's. Bracing does go along the rear panel, but it can easily be cut out for plate amp installation.


Next up is a sealed box 16" wide x 19" tall x 18" deep with a double baffle. Notice an extra horizontal brace. Net volume is around 2.25 cu ft. Good size for many sealed 12's, some ported 10's? This is plate amp installation friendly.


Stepping up to the bigger boxes. 18" wide x 23" tall x 20" deep with a double baffle. This size gets 2 vertical and 2 horizontal braces. Not volume comes in around 3.5 cu ft which should be great for sealed 15's and some ported 12's. Again, installing a plate amp will be easy.


The box for the 18" was going to be 22" wide, and it still can be. But I went ahead and had them make it 23" wide x 23" tall x 20" deep and of course with a double baffle. There's an optional brace that can be used to tie in the front portion of the box even more than the previous photo showed. This box is not as plate amplifier friendly because I figured most people would be using pro amps. I can always get them to change one of the shelf braces to allow for an easier plate amp to be installed if needed. Anyway, this box nets a very nice 4.5 cu ft. If we decide on 22" wide, that would drop to a little more than 4.25 cu ft after we subtract off bracing volume.




If anyone can think of a different size or shape that might make sense, please let me know. I'm not the best at modeling subwoofers so if anyone would like to see a ported design for a specific driver, I'll do my best to get things rolling.

If anyone would like to make suggestions on some very common models that should have a specific enclosure......sealed or ported......I'll see what I can do.

Since most 18's probably enjoy bigger boxes, i'd say 4.5cuft is perfect.

As for other shapes, you could always do a more rectangular box for thinner footprint?
Just a suggestion.
I'm more then satisfied with how the 18's look, and I think the rest of us are in the same boat.
Reply
Reply
post #107 of 679
4/27/12 at 8:23pm
Thread Starter 
Quote:
Originally Posted by bluestang View Post

I like the look/size of the smallest one. I wonder how having 2 of these running a Dayton 12" HF or HO would perform?

Remember though, the photos don't show the front baffle. What you see in the pictures are the first layer baffle. Another layer covering all of that will lay flush on the front of the box.
Reply
Reply
post #108 of 679
4/27/12 at 8:29pm
Thread Starter 
Quote:
Originally Posted by Thatsnasty View Post

Since most 18's probably enjoy bigger boxes, i'd say 4.5cuft is perfect.

As for other shapes, you could always do a more rectangular box for thinner footprint?
Just a suggestion.
I'm more then satisfied with how the 18's look, and I think the rest of us are in the same boat.


I'm going to have one more prototype cut for the 18" subs. It will be about a 22" cube which would basically give the same volume as the 23"x23"x20" model I posted.


Guys, I will work on shipping weights this weekend and they should be available to order next week sometime. I've already got some that can be shipped now, but I want to double check everything first.

I only have 2 prototypes for the larger boxes 18" drivers because I want to try another shape before cutting begins. So those won't be available for another week.
Reply
Reply
post #109 of 679
4/28/12 at 3:47am
These boxes look great. Thinking about the bracing and having it look good or perform. Thought maybe data-bass could do a test like the stuffing one they did to determine how much bracing makes a difference. Your designs would work well for building a couple with and without bracing for testing. Audioholics did there modeling study but it would be nice to see some real measurement data.
Reply
Reply
post #110 of 679
4/28/12 at 9:19am
i agree. that is what i was struggling with after erich reminded how important perceptions are again. so unless such a study is performed, you've got to go with his design and it wouldn't be fair to put performing such a test on his shoulders.
Reply
Reply
post #111 of 679
4/28/12 at 11:17am
I think Erich's doing a great job with the bracing. Sure no one will see the bracing once the sub is installed but you know how we DIY folk like to take pics

From personal experience with the LMS Ultra I can say that no amount of bracing is over-kill for that sub. You also want weight in the enclosure for high excursion subs like the LMS and XXX or the enclosure will move. I had what I thought was a well braced temporary enclosure for the LMS while I built new ones. The LMS pushed it about 5" till it was resting against the wall. That never happened with my new enclosures that had a similar bracing scheme to what Erich's doing. The LMS sounded better in the new heavily braced cabinets as well, it sounded tighter and more accurate.

I was planning on making some more 18" enclosures but now that I see what Erich has cooked up I am going to order them from him instead.
Reply
Reply
post #112 of 679
4/28/12 at 8:24pm
Quote:
Originally Posted by Sibuna View Post

every time i see someone posts in this thread all i can think is ..

Yeah ive thrown couple hunno at the screen and no box has showed up.

Im in for two 18" 23x23x20.... maybe a 2cu ft box for a 12" as well!!
Reply
Reply
post #113 of 679
4/30/12 at 4:52pm
Thread Starter 
I've got some possible good news about the sealed 18" box.

There was another prototype made that I liked better. After looking over the 23"x23"x20" deep box, I didn't like how far back the bracing had to be. The only reason I went with that size was to share the same 23x20 side panels with the other box. But that really doesn't make much sense anymore.


So I had a 22" cube made up instead, basically decreasing the width/height by 1" and extending the back of the box by 2". Then redesigned the bracing so that it moved forward about 2" and put the crossbrace more towards the center of the panels.


I taped it up tonight and I think it looks better and the bracing makes more sense. I didn't expect to get it this soon and left my camera at home. I might get back down there tonight for pictures.

Boxes for these are about $2.50 each for the double thick cardboard. I've got access to plenty of foam sheets from a local company, but I might try the corner protectors they use to protect the corners of pallets.

The packaging for the 18" boxes is not going to please FedEx at all. about 24" x 24" x 8" or so. They won't look very heavy.......but they'll be in for a shocker when they pick them up. I'm going to have to package these to take a beating.



There's a chance I might also get regular cubes for the 15" and 12" as well. I like the current shape of the 12" and 15", but maybe there should be a couple extra options? In the next few days we should also see prototypes for dual opposed 10's and 12's. I'll get the current models ready to go in the next couple days.
Reply
Reply
post #114 of 679
4/30/12 at 6:53pm
I wish I lived in Ohio know, not only would pester you so often for flat packs that you would finally give in and let me buy everything your making up NOW! But I also might run into the chesty Lonnie Anderson lookalikes from WKRP in Cincinnati, mmmmmmm......chesty platinum blondes......ohhhhhh
Reply
Reply
post #115 of 679
4/30/12 at 7:06pm
These look awesome, I can't wait to see the Birch options since that's what I built the rest of my speakers out of.
Reply
Reply
post #116 of 679
5/1/12 at 9:23am
Erich,
Is there a dual opposed 15 box in the future?

Thanks.
Jake
Reply
Reply
post #117 of 679
5/1/12 at 10:14am
Quote:
Originally Posted by mjaudio View Post

I think Erich's doing a great job with the bracing. Sure no one will see the bracing once the sub is installed but you know how we DIY folk like to take pics

From personal experience with the LMS Ultra I can say that no amount of bracing is over-kill for that sub. You also want weight in the enclosure for high excursion subs like the LMS and XXX or the enclosure will move. I had what I thought was a well braced temporary enclosure for the LMS while I built new ones. The LMS pushed it about 5" till it was resting against the wall. That never happened with my new enclosures that had a similar bracing scheme to what Erich's doing. The LMS sounded better in the new heavily braced cabinets as well, it sounded tighter and more accurate.

I was planning on making some more 18" enclosures but now that I see what Erich has cooked up I am going to order them from him instead.

I cant +1 this enough!!! Im currently putting off building new boxes for my XXX18's that will have way more bracing and weight to them... Id buy from you Erich, but I need 7 cuft or more :/ haha.
Reply
Reply
post #118 of 679
5/1/12 at 1:03pm
Quote:
Originally Posted by beastaudio View Post

I cant +1 this enough!!! Im currently putting off building new boxes for my XXX18's that will have way more bracing and weight to them... Id buy from you Erich, but I need 7 cuft or more :/ haha.

So your XXX 18's are pushing your old boxes around

I don't think people realize that the weight of the LMS and XXX combined with the long throw really wreaks havoc on lesser enclosures. I still think the Mael-X is a great sub, I have 3, but compared to the LMS it is just not as violent in it's attack and I am sure the XXX is the same.

You could always buy 2 of Erich's 18" enclosure's, glue them together, and add another layer 3/4" around for a 8cuft box that would be a bear to move
Reply
Reply
post #119 of 679
5/1/12 at 1:13pm
Quote:
Originally Posted by Maklar View Post

These look awesome, I can't wait to see the Birch options since that's what I built the rest of my speakers out of.

yea its gonna be hard to wait for them once the MDF ones are available
Reply
Reply
post #120 of 679
5/1/12 at 1:40pm
Quote:
Originally Posted by mjaudio View Post

So your XXX 18's are pushing your old boxes around

I don't think people realize that the weight of the LMS and XXX combined with the long throw really wreaks havoc on lesser enclosures. I still think the Mael-X is a great sub, I have 3, but compared to the LMS it is just not as violent in it's attack and I am sure the XXX is the same.

You could always buy 2 of Erich's 18" enclosure's, glue them together, and add another layer 3/4" around for a 8cuft box that would be a bear to move

Holy Moley, yea thatd be a pretty stout deal. This time im just going to go with a LOT more bracing, add another panel to the front to recess the driver a bit instead of just top mounted, and double baffle the rear. that should do it
Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs

AVS Top Picks

AVS › AVS Forum › Audio › DIY Speakers and Subs › Dimensions for sealed 18" sub box