Statements Build- 80L, Curved Side, Slot Ports

[yzracer14]

Good day fellow members. I’ve been lurking around here for a long time now and finally decided to post since I’m approaching the construction portion of my plans.

I will be building curved side; 80L vented Statement Mains with 2 slot ports at 46" tall. Curt suggested the 2 slot ports + 80L idea HERE. Since I’m unsure what the exact tweeter height will need to be because my entire living/theater room will be renovated over the next year, I will design a base to be easily modified for height without changing any of the other aesthetics. The smaller slot vented version has the added benefit of saving $100+ in cash for not having to buy the ports and since the speaker (without base) will be less than 48”, only two ¼” sheets of bendable plywood will be needed. I am also contemplating an externally mounted crossover in a breathable plexiglass enclosure.

I've attached a pic of the SketchUp 3D model for your viewing pleasure. I'll post some more detailed plans at another time, but for now, the specs.

I plan to start cutting out the braces for the skeleton this weekend.

FYI - The baffles pictured are for the full size Statements for comparison to size.

[snmhanson]

I like your design. It will be interesting to see how the slot ports look - should be pretty cool. What is the radius of your curves? I have had good results bending 1/4" mdf around a 6' radius and could probably go down to a 5' radius. Bendable plywood may not be necessary - unless of course you have other reasons for using it. I am guessing mdf would be quite a bit cheaper than bendable plywood though. Keep us updated on the build! I never get tired if seeing Statement builds.

Matt

[engr_dave]

Looks great YZ. I'm looking forward to following this build... keep us posted. I think there are some sealed statements in my near future. I've never done curved cabs; these may have to become the first!

[yzracer14]

The radius is 2'-4.25". I know it's an odd radius; I just eyeballed it and that's what ended up looking "right" to me. I have been thinking about using 1/4" MDF but I don't think it will work without kerfing. I will test it out before moving forward with the bendable ply.

[NickS]

You might also look into 1/8" hardboard. I find it to be quite bendable.

[Hdale85]

Hardboard is the way to go, kerfing was just a headache in the end for me and I dumped it and went for the hardboard.

[kmibb]

Just a few concerns:

Did you change the length of the middle tunnel at all? That would not be a good thing.

How are you calculating the tuning of a curved slot port? Seems difficult.

[yzracer14]

The port isnt going to be curved. It will be a rectangular port both on the top and bottom of the cabinet.

The mid-tunnel length hasn't changed, despite using a 1.5" baffle and the total cabinet depth remaining unchanged. I'll be able to accomplish this by routing out 1/4" from the 5" x 5" square on the back of the baffle for the mids, effectively keeping the mid-tunnel length unchanged.

I decided to try out a few more cabinet designs before cutting anything. I think I've settled on a fatter-looking cabinet (shortened the radius). I just need to get it into 3D and I'll post the updated design.

[yzracer14]

Enclosure update.

I settled on this look. It's fatter, 5.5" shorter than my original enclosure, and approximately 82 Liters.

[Face]

By fatter do you mean wider? That's no good.

[AdelaaR]

It does indeed look like the baffle is wider in that last drawing there, OP.
I'm no expert but I was told changing the baffle width is not an option as it completely changes the design of the speaker, acoustically speaking.

[yzracer14]

It has been made a bit wider where it bulges on the sides, but the baffle width remains unchanged. It may be because that pic doesn't show it with the baffles on, but I promise that I have not messed with the critical dimensions.

[yzracer14]

Got quite a bit of MDF precut and ready to start shaping the braces.

This build will probably go a bit slower than most. I have everything I need to build the enclosure, but an unfortunate injury to one of my hands has left me with very limited use of it. But these speakers WILL be built. I had enough guts to tell the wife that I wasn't letting this build sit on the back burner for a 3rd year in a row 8O

[Ironman129]

Wish you a quick recovery with the hand. As you know I am following this thread very closely. Would love to see some pics as you're going through the build!

[Coconutout]

is the sonic benefit alone worth the trouble of making curved enclosures?

[yzracer14]

I have no idea TBH. I know there are sonic benefits to it, but I've never built the same set of speakers both curved and uncurved to compare. I'm only doing it because the wife didn't want a rectangular box.

[BeerParty]

is the sonic benefit alone worth the trouble of making curved enclosures?

Who is claiming there is a sonic benefit to making a curved enclosure?

[Hdale85]

Curved enclosures break up the back wave of the drivers so they don't come back to the drivers reducing distortion.

[Face]

Curved enclosures break up the back wave of the drivers so they don't come back to the drivers reducing distortion.

With a dipole midrange? :B

[yzracer14]

Progress!

Mid-tunnel assemblies. I went with 1/2" for the sides, but I'm not satisfied with the knuckle test so to fix this, I will be gluing two 1/8" hardboard pieces to the mid-tunnel sides. The dado is 5/16" deep. I still have yet to cut out the holes but I haven't fully settled on whether or not this will be sealed or vented so I will hold off on this until that decision is made. If I go sealed, then the holes aren't needed, so I'm not cutting until I'm sure.





Woofer brace. this one will be used as the template for the other three and in the end will be rounded over.

[yzracer14]

Made a bit more progress. I will hopefully be gluing up tomorrow if all goes well tonight.

#1 Tip so far: I highly suggest laminating the face of any jig where the bearing on the router will touch, with masonite. The first few jigs I made where just of MDF, but after just a few passes, the MDF starts to indent where the bearing rides and that causes out of tolerance cuts. Laminating the bearing-riding faces with masonite gave me perfect tolerance dados every time.

PICTURES

Here's the tool that makes me the happiest. It has never failed me; Always accurate, and always smooth.



DADO! I still need to chamfer the mids and woofers, as well as finish the tweeter cutout and mid-tunnel notches.



Oops... :x Break out the bondo



30 seconds later... :M



These are coming out better than I thought. I know its one of those "never gonna see it again" parts, but when has that stopped any of us from making it look sexy anyways?



The template used for that shape.

[Jim Holtz]

Sweet! :T

Jim

[JonMarsh]

Progressing nicely! Good tip, experience is always a capable teacher.

[yzracer14]

Progressing even slower now due to work training; but it's still progress right?

I got the inner-front baffle and back glued up with the braces and tunnels. Although it turned out well, and it wasn't easy, I made the mistake of gluing all the pieces together at once 8O . It was a major PITA getting them all to line up properly. On the second tower, I will use the back to line up the parts while the inner-front baffle dries and glue the back on the following day. It will take more time, but much less room for error. Cuz there was a point where I really thought I was gonna have to start over. A rubber mallet and brute strength as a desperate last resort saved it.

Pics to be posted later.

[yzracer14]

I know these pics are pretty late, but it honestly took me forever to come up with a clamping system capable of clamping without leaving gaps. This is finally what I have come up with. I'm using the angled scraps that match up perfectly with the front and rear angled faces allowing me to achieve a perfect seal on these areas. To prevent these scrap pieces from sliding off, I had to use alignment blocks and a few clamps. It's nothing too fancy, but I'm satisfied with the results. These pics show the second layer being clamped to one side. I will post pics again once fully skinned.

Edit: I just realized I never posted detail shots (woofer chamfering, ports, etc). I will do so once the clamps come off tomorrow.

[CADman_ks]

...

Progress is looking good, and like you said, progress is progress.

I have never built curved cabs, but I have employed the salt bag weight method (about 5 bags) for gluing multiple panels together to form a 1 1/2" MDF sheet, and it works pretty darn slick...

CADman_ks

[yzracer14]

The left side of these images are blurry for some reason. Sorry for that, but you can still see what you need too.

I have added salt bags to my list of speaker building necessities... 8)

Having visions of a curved CC....



Slot Port. Primarily made up of 3/4" MDF with an extra 1/2" on the last 1-1/4" so that I could put a 1/2" roundover on the inside and outside.



Backside. I cannot cut out the ports or mid-tunnels until the sides are completely finished.

[BeerParty]

Slot Port. Primarily made up of 3/4" MDF with an extra 1/2" on the last 1-1/4" so that I could put a 1/2" roundover on the inside and outside.

That slot port is going to look cool when you open up the back of the cabinets. Well done.

[yzracer14]

Here's a close-up of the HDF edges once trimmed and sanded flush.



Woofer chamfering



First layer on the other side being test clamped and pre-bent. I found that pre bending really makes gluing the first layer a cinch.

[CADman_ks]

Here's a close-up of the HDF edges once trimmed and sanded flush.



...

Seeing this picture drives home for me what you're up against! SIX layers of HDF! WOW!

Just how much glue does a guy go thru when he's doing something like this???

[yzracer14]

Seeing this picture drives home for me what you're up against! SIX layers of HDF! WOW!

Just how much glue does a guy go thru when he's doing something like this???

the first layer isn't all that much, but each layer after that needs 8+ ounces of glue, or half a TBII squeeze bottle. Doing some quick math, I just realized that I'm going to need to buy another gallon of TBII. 8O

I can't wait to weigh this thing! It's so heavy on the one side that I couldn't stand it up straight to take pictures without it falling.

[CADman_ks]

the first layer isn't all that much, but each layer after that needs 8+ ounces of glue, or half a TBII squeeze bottle. Doing some quick math, I just realized that I'm going to need to buy another gallon of TBII. 8O
...

WOW!!!8O8O That is a LOT of glue!!

...

I can't wait to weigh this thing! It's so heavy on the one side that I couldn't stand it up straight to take pictures without it falling.

LOL!!! :B

[CADman_ks]

... but each layer after that needs 8+ ounces of glue, or half a TBII squeeze bottle.
...

This also has me rethinking the amount of glue that I've purchased for doing veneer. I thought that a 16oz bottle would do all (4) of my Ochocinco cabs, but now I'm questioning that wisdom.

I have a LOT of surfaces to cover...

[yzracer14]

The sides glued on:

[Coconutout]

wowow looking great. this is inspirational.

hardboard for my next build for sure

have you tried the knuckle test, yet?

[AdelaaR]

Fantastic work there!

[CADman_ks]

These are looking GREAT!!!

As I look at more speaker designs, I'm drawn into these curved cabinet designs. They really look nice.

With all of the extra work that goes into them, I have to think that the satisfaction quotient is a lot higher as well when you're done!

But one thing that I've been curious about is how you trim off the hard board, specifically at the arrows:

[Hdale85]

You can make a guide that would flatten out your router against the curve, and use a flush trim bit. I think for mine I just used a jig saw though. But his are looking much cleaner then mine ever did. I built mine in a dining room though with very little tools.

[CADman_ks]

You can make a guide that would flatten out your router against the curve, and use a flush trim bit. ...

I can imagine how this would work, but I can't see how it would work. I would think that you would need to have a pretty long flush trim bit (which they might make, but I don't have), and you would need to have quite a bit, if not all of it, sticking past the platen of the router. Could work, I guess if the bit was long enough.

... I think for mine I just used a jig saw though. But his are looking much cleaner then mine ever did. ...

One nice thing about a jigsaw, is that you could get the angle just right. If you could somehow trim it close, and then final hand sand it with a block, that method might not work too bad.

... I built mine in a dining room though with very little tools.

LOL!!! I have visions of those guys that build motorcycles in their living rooms, and never finish. Eventually the motorcycle becomes their coffee table!!!

A mans gotta do what a mans gotta do. :T

[yzracer14]

I need to trim the last of the hardboard tonight. So I'll post detailed pics tonight.

[CADman_ks]

I need to trim the last of the hardboard tonight. So I'll post detailed pics tonight.

cool... :T

[yzracer14]

Here's the last edge that needs to be trimmed.



Here's my router with a flush trim bit. I needed to stack 3/4" scrap pieces from the braces to get enough height for my bit.



Don't try to get it flush with the router cuz you will mess it up. Get it close, like 1/32". After that I burn through 95% of it with a random orbital sander and 60 grit (it will feel flush, but it's not really). The last 5% is a slight dome that's left behind because of the the pad which naturally domes when edge sanding, which is essentially what is done here. This last little bit is knocked down with a scrap piece of mdf used as a sanding block with 60 grit. The end result are the corners you pointed out.

[CADman_ks]

Here's the last edge that needs to be trimmed.



...

I would have thought that you could trim THIS side with a standard flush trim but with a bearing on the bottom, but I can see this would would work well.

Maybe my arrows where in a bad position. Do you use this same technique then for the LONG straight runs up and down the height of the cabinet? That's the joint that I was trying to point out with the arrows.

But, at the end of the day, this is what I like the most about DIY, and particularly this site. There is almost always someone out there that has done what you want to do, and they are willing to share techniques on how to get things done. And many times, there is more than one technique to get something accomplished, and one guys method might work better than other methods already out there.

Thanks for the information!! :T

LOOKING GOOD!!! 8)

[yzracer14]

Yes, the same technique was used on the long straight runs.

Thank you guys for the compliments. It's DIY build threads, and the amazing designs, that inspired me. I feel its only fair that I contribute to the DIY community. If nobody posted their builds, or methods, we'd still be considering buying off the shelf rather than going down the rabbit hole of DIY 8O ....

[CADman_ks]

Yes, the same technique was used on the long straight runs....

:T

... It's DIY build threads, and the amazing designs, that inspired me. I feel its only fair that I contribute to the DIY community. If nobody posted their builds, or methods, we'd still be considering buying off the shelf rather than going down the rabbit hole of DIY 8O ....

:agree: +1 here...