DIY Speaker With Curved Sided Cabinet

tryrrthg

I just wanted to share a little project I've been working on the last couple weeks. I am building a simple MT, 2 way speaker. The design is called the Modula MT, it was designed by a guy over at the HT Guide forums. It is designed around the Dayton Audio Reference Series mid and Seas 27TDFC tweeter. There are other designs for different tweeters, like the Dayton Reference Series tweeter. I went with the Seas because it is a soft dome instead of metal.

This is my first speaker build (I've built subs before) and I probably should have done something a little easier, but I wanted to build something a little more exciting than a standard box speaker. I also wanted a floorstanding speaker so that I didn't have to mess with stands. So I figured I'd try my hand at a curved sided cabinet, kind of like the Sonus Faber Cremona series. I had a friend of mine model the shape of the enclosure in CAD software, then I just printed it out, traced it to a piece of MDF, and cut it out with a jigsaw. Once it was sanded to a smooth looking curve I could use that piece as a template to cut the remaing braces using my router with a flush trim bit. Using a flush trim bit ensures that all the braces are the exact same size and shape.

After cutting all the braces I cut some dados in the inner baffles for the braces to slide into. the inner baffles are 1/2" MDF and are used to hold the brace skeleton together. Once the braces and inner baffles are glued together I can apply the curved sides. I will be using layers of 1/8" hardboard (which is like a pegboard material) for the sides. I would have used bendable plywood (wiggle wood) but it was more expensive than I wanted to sink into this project. Hardboard is MUCH cheaper. It is pretty dense and flexible enough to use.

Once all the sides are on I will add another 1/2" outer baffle to the front and back. I am going to try applying the first layer of side pieces tonight.

I've attached a few pics but there are a few more in the link below.

http://www.angelfire.com/planet/tryrrthg2/modulamt/

SolidSqual

That looks like it will be a great project once complete! I wish I had the time and tools . . .

MSALLA

Could you go in to detail on how you will do the sides? I wanted to do something like that but was nervous.

tryrrthg

MSALLA wrote: »

Could you go in to detail on how you will do the sides? I wanted to do something like that but was nervous.

I put the first layer on tonight. Kind of frustrating, but it went better than expected.

I used the 1/8" hardboard. I clamped the front down so that it would stay put and then used ratcheting tie downs to curve the panel around the braces. I also used a few brad nails to help mold it to the braces and hold it down (my air nailer was VERY handy for that). I will flush mount the overlap after all the layers are put on.

The attached pictures should help explain things. if not I'm doing the same process the guy in the link below did only I am not using the bendable plywood like he did.

Link

If you have any more questions let me know, I'll try my best to explain the process...

VR3

That looks tedious as hell.

Cool though.

Systems

Wow very nice,It looks like a lot more work than a regular box but the end result should be a great looking speaker.Are you going to veneer them?

tryrrthg

GV#27 wrote: »

Wow very nice,It looks like a lot more work than a regular box but the end result should be a great looking speaker.Are you going to veneer them?

Yep, they will be wrapped in veneer. Probably quartersawn white oak veneer to match the rest of the mission/arts and crafts furniture in our house.

ben62670

Very nice. Brave step for first speaker project. It looks like it is coming along good. I get much satisfaction out of doing things myself. don't let anything discourage you. Screw ups are just minor lessons. What will you be using for crossovers? Is PE going to design them for you?

Enjoy Ben

tryrrthg

ben62670 wrote: »

Very nice. Brave step for first speaker project. It looks like it is coming along good. I get much satisfaction out of doing things myself. don't let anything discourage you. Screw ups are just minor lessons. What will you be using for crossovers? Is PE going to design them for you?

Enjoy Ben

The speaker was designed by a guy at the HT Guide Forum. The design is called the Modula MT. Crossover is already designed for me, I don't have the time, patience, or knowledge to design a speaker/crossover myself. I'll stick to the tried and tested designs that are out there.

It's not exactly my first speaker project, I've build two subs, I built the sub linked in my signature a few years ago. I saw the curved cabinet design over at HT guide and thought I'd give it a try. It's not terribly difficult, just tedious...

ben62670

tryrrthg wrote: »

The speaker was designed by a guy at the HT Guide Forum. The design is called the Modula MT. Crossover is already designed for me, I don't have the time, patience, or knowledge to design a speaker/crossover myself. I'll stick to the tried and tested designs that are out there.

It's not exactly my first speaker project, I've build two subs, I built the sub linked in my signature a few years ago. I saw the curved cabinet design over at HT guide and thought I'd give it a try. It's not terribly difficult, just tedious...

Excellent. Crossover design is a PIA. I have tried different crossover designs, and if they just aren't perfect its tough to figure out what is wrong.

Can't wait to see the finished project!:)

Ender

This is a bit of a necromantic move, but aren't the side pieces too thin? They look like they could vibrate like paper in a strong wind.

Also, so you just bend the wood and it stays as is or did you glue the whole thing on and then cut the extraneous areas off?

leroyjr1

Ender wrote: »

This is a bit of a necromantic move, but aren't the side pieces too thin? They look like they could vibrate like paper in a strong wind.

Also, so you just bend the wood and it stays as is or did you glue the whole thing on and then cut the extraneous areas off?

He'll layer the sides maybe 2 or 3 pieces glued together.

nooshinjohn

Fantastic work! I wonder how an SDA type speaker would sound inside a curved cabinet... Ben, care to try that one?

Ender

Oh SHNAP! That's hot. But, judging from the glue on my newly purchased SDA 1C's (glue that is failing to keep the side grills attached) and the presumed tension on the bent pieces of wood, might the speakers not fall apart within a couple decades?

Also, so he did cut off the ends that were sticking out?

Face

I wish I had the patience for that.

Systems

Face wrote: »

I wish I had the patience for that.

Yeah that's labour intensive stuff .A nice little CNC router would be handy for cutting those braces.

Ricardo

Looking great Troy. You should build a pair for me

tryrrthg

Wow, this project is two years old already? Time flies.

This was just before my wife and I found out we were going to be parents. So shortly after this my "honey do" list grew exponentially and I never finished the speakers. My son is 17 months old now and there is no time for speaker building...

To answer a few questions. I was going to layer the 1/8" hardboard on until the sides were 3/4" thick. it was a tedius process, that's for sure. after everything was attached I would use my router to flush trim everything.

Ender

Got it. Damn, sad that you didn't get to finish these. They look like they could be phenomenal.

tryrrthg

This was probably too much effort for a DIY speaker design that you could buy the parts for $200 (although still a fantastic value), so it's probably a good idea that I didn't spend anymore time. The effort would probably be more warranted for a balls to the wall design.

I did end up building a DIY MTM that is the big brother of this design. although, those were a boring box that I never bothered to veneer (no time). I ended up scrapping that project too. I see a pattern here.

John30_30

tryrrthg wrote: »

Yep, they will be wrapped in veneer. Probably quartersawn white oak veneer to match the rest of the mission/arts and crafts furniture in our house.

Schweet. I love quartersawn white.

Oh.

Oh.


Never mind.

nooshinjohn

do you still have the cabinets? If so would you be interested in parting with them?

tryrrthg

nooshinjohn wrote: »

do you still have the cabinets? If so would you be interested in parting with them?

I do still have them. Not sure I'm ready to part with them yet... maybe when I finally get around to cleaning out the basement and am forced to throw stuff out. I wouldn't mind trying to finish them at some point though...

They are in pretty much the same state as the last pictures I posted would you still be interested in incomplete enclosures?

jacob.simpson

Very nice work,
please post how it sounds with a detailed review,
what components are you going to use in them

nooshinjohn

tryrrthg wrote: »

I do still have them. Not sure I'm ready to part with them yet... maybe when I finally get around to cleaning out the basement and am forced to throw stuff out. I wouldn't mind trying to finish them at some point though...

They are in pretty much the same state as the last pictures I posted would you still be interested in incomplete enclosures?

pm sent...

AudioGenics

most impressive.

shon39us

tryrrthg wrote: »

I just wanted to share a little project I've been working on the last couple weeks. I am building a simple MT, 2 way speaker. The design is called the Modula MT, it was designed by a guy over at the HT Guide forums. It is designed around the Dayton Audio Reference Series mid and Seas 27TDFC tweeter. There are other designs for different tweeters, like the Dayton Reference Series tweeter. I went with the Seas because it is a soft dome instead of metal.

This is my first speaker build (I've built subs before) and I probably should have done something a little easier, but I wanted to build something a little more exciting than a standard box speaker. I also wanted a floorstanding speaker so that I didn't have to mess with stands. So I figured I'd try my hand at a curved sided cabinet, kind of like the Sonus Faber Cremona series. I had a friend of mine model the shape of the enclosure in CAD software, then I just printed it out, traced it to a piece of MDF, and cut it out with a jigsaw. Once it was sanded to a smooth looking curve I could use that piece as a template to cut the remaing braces using my router with a flush trim bit. Using a flush trim bit ensures that all the braces are the exact same size and shape.

After cutting all the braces I cut some dados in the inner baffles for the braces to slide into. the inner baffles are 1/2" MDF and are used to hold the brace skeleton together. Once the braces and inner baffles are glued together I can apply the curved sides. I will be using layers of 1/8" hardboard (which is like a pegboard material) for the sides. I would have used bendable plywood (wiggle wood) but it was more expensive than I wanted to sink into this project. Hardboard is MUCH cheaper. It is pretty dense and flexible enough to use.

Once all the sides are on I will add another 1/2" outer baffle to the front and back. I am going to try applying the first layer of side pieces tonight.

I've attached a few pics but there are a few more in the link below.

http://www.angelfire.com/planet/tryrrthg2/modulamt/

Hi, I was wonder what did use to create this angle, and how to determine the depth of the enclosure?

shon39us

tryrrthg

shon39us wrote: »

Hi, I was wonder what did use to create this angle, and how to determine the depth of the enclosure?

shon39us

With any speaker design it is designed around a certain internal enclosure volume and front baffle width. I knew that the enclosure volume needed to be around .75 cubic feet. I also knew the front baffle width needed to be around 9 inches. Having those two bits of information I asked my buddy, who works with CAD software, to draw me up some shapes until I found a shape that looked good. The CAD program could figure the area of the shape (without me having to do some calculus) which I could then use to calculate the needed parameters to achieve the .75 cubic feet of interior volume (multiplying the area of the shape by height and subtracting out anything that would take up internal volume, like braces, etc).

Depth of enclosure is not a big deal, but from what I understand the deeper the better - so the rear wave doesn’t bounce back, or something like that…

stewbaca

Very cool and very nice. Do you have the original "top" cutout that you printed stored electronically. I would love to get that and the overall height you used for a .75ft3 volume. If you have this info would you pm me and I will give you my email address and you can send it. I would think that would be all the info necessary to build these as the rest just kind of falls into place.

Mike

20hz

leroyjr1 wrote: »

He'll layer the sides maybe 2 or 3 pieces glued together.

I have wanted to build a pair of surrounds with curved sides we get this
?bender board? between our sheets of plywood looks ok maybe its ash not as smooth but I would fill and go black anyway, its very flexable maybe bends to a 15" circle , I was planning on bonding 4 pieces whats nice about unparallel sides is it wont have to be monster thick because internal resonances dont happen as much , I found this out when I built a tube sub it was only 1/4" thick and it sounded awesome .

longdrive03

Just found this topic. I'm building some large clones of the Klipsch RF7 using curved sides. There is an easier way by using bendable 1/2" plywood and doing two layers. I cut out five braces (top and bottom are solid and middle three have holes to allow air flow. PL Premium adhesive holds the ply with about two million staples/nails. I veneered mine with aircraft grade cherry veneer and solid cherry top. Just about to install speakers after applying Minwax wipe on poly.

I also installed a thin layer of perforated cabinet drawer lining between the ply with lots of Titebond glue rolled on. The bendable ply is $30 a sheet I used nearly two sheets. Cabinet is 48" tall and 17" deep and 14" wide at front and 5" wide at rear. I basically laid out the front and rear widths then used a strip of the ply to bend and make an arc. I cut the arcs out with jigsaw and then made a template using a flush trim (or pattern bit) on my router using only one side then flipping it for second cut so both would be identical. I also had vertical braces in the center of the braces on the sides.