Ardent Speaker Camp

[JonMarsh]

yes- the top front panel sub sections are already veneered- same concept, birds eye maple, and figured maple. I "might" cheap out and go with paper backed for the sides, but probably not... will probably use the same solid veneer I'm using on the first set. It looks too nice... and considering how much work everything else is just to build the cabinet, it would be penny wise and pound foolish.

This is from my veneer finishing test block, done with Behlen Por-O-Pac filler and Deft lacquer sanding sealer and lacquer.



I realize it's pretty hopeless to try to explain this with a picture- figured maple will change it's hue depending on the angle of light, and your viewing angle- and light areas go darker, while dark areas go lighter, like a photographic negative- so while unstained figured maple may at first blush seem boring, it's anything but with a closer look.

Also, it's a subtler look than I've done in the past, but something I think I'll be able to live with, without getting tired of it.

[savage25xtreme]

:dothewave: we need pictures! :T

[JonMarsh]

Pictures?

Unfortunately, when I say I'm just doing detail work that's not very picture worthy, that's pretty much what I mean.

Soooo, you want pictures? How about these exciting maple midrange driver braces?



Aren't those sweet?

You can even see them installed the front panels!!




:E



And for those of you that just have to be in on the bleeding edge of what's happening, how about this riveting shot of a dry fit test of the back, sides, a center brace (not installed correctly, rotated 90 degrees off), and side braces? It doesn't get much better than this!! :W



Seriously, the epoxy is setting on mounting the midrange enclosures to the front panel, and for the side braces in the sides- this industrial/marine stuff is slow but strong. The top panels, sides, and front panel have had a visit from the DeWalt Jointer so they're ready for "biscuits for breakfast" tomorrow morning. Whispermat II has been "adhered" with 3M 90 to selected parts of the back panels and to the inside of the top panels, and the checklist has been completed down to the final tricky stage of mating front, sides, back and top together.

As I'm having dinner with my daughter this evening, things won't get all mated up until tomorrow morning- and that means that tomorrow we should, read "Should", have recognizable boxes. :T

Otherwise, today I've been working on veneering press fixturing for the facets and sides. Boy, that is one thrill a minute, but if I don't do it, who will? :W

[Hdale85]

Those panels look amazingly nice though

[Bear]

Those panels look amazingly nice though

And HEAVY!

[JonMarsh]

What? Heavy? Is something wrong with the Earth's gravitational field again?

Believe me, this time tomorrow, you're going to see some serious shenanigans!

[PhilDSP]

Very, very nice! That figured maple just screams out for having a flamed finish like you see sometimes on fine electric guitars, even hollow-bodied ones.

[Curly Woods]

Very, very nice! That figured maple just screams out for having a flamed finish like you see sometimes on fine electric guitars, even hollow-bodied ones.

Better known as "starburst" or "sunburst" finish.

[bigg]

Seriously, the epoxy is setting on mounting the midrange enclosures to the front panel, and for the side braces in the sides- this industrial/marine stuff is slow but strong. The top panels, sides, and front panel have had a visit from the DeWalt Jointer so they're ready for "biscuits for breakfast" tomorrow morning. Whispermat II has been "adhered" with 3M 90 to selected parts of the back panels and to the inside of the top panels, and the checklist has been completed down to the final tricky stage of mating front, sides, back and top together. :W

Epoxy? And what is 3M 90? I've been using Titebond 3 for my speaker cabinets. I've had very good luck with this stuff so far. When I cut my speaker holes, I throw the 'blanks' against the concrete floor and they don't come apart. But I leave mine clamped for at least three days. Sometimes longer depending on work etc. But I would like to know the opinions of some of you speaker building veterans. ;x(

[Johnloudb]

I think this is what he's using ... for attaching the wisper mat.

http://3m.hillas.com/c-984-3m-hi-strength-90-spray-adhesive.aspx?gclid=CLa94vizjJwCFQk_agodJCQSWw

I've always used Elmer's wood glue. And, I once tried to break a joint where two small pieces of wood were glued together and couldn't do it. I've never tried anything else for wood construction though.

Maybe epoxy is more flexible? mosture resistant? Jon, you still in bed ... time to get up!

[Paul Ebert]

...Otherwise, today I've been working on veneering press fixturing for the facets and sides. Boy, that is one thrill a minute, but if I don't do it, who will? :W

Exceedingly interested in what you come up with for that.

[JonMarsh]

I think this is what he's using ... for attaching the wisper mat.

http://3m.hillas.com/c-984-3m-hi-strength-90-spray-adhesive.aspx?gclid=CLa94vizjJwCFQk_agodJCQSWw

I've always used Elmer's wood glue. And, I once tried to break a joint where two small pieces of wood were glued together and couldn't do it. I've never tried anything else for wood construction though.

Maybe epoxy is more flexible? mosture resistant? Jon, you still in bed ... time to get up!

Correctamundo on the 3M 90- basically, it's a very high grade conctact cement in a can. Perfect for smaller jobs, no brushes or rollers to clean up.

For smaller panel laminations and piece parts, I usually use Titebond III- not particularly because of the water resistance, though that doesn't hurt, but because of the way it sets up works, and because it doesn't shrink at it hardens, in my experience, compared with Titebond II. What can I say, I just like the way it behaves?

For complete cabinet assemblies, with intricate construction, Titebond or Elmers won't do any gap filling with strength- not even small amounts. I could probably get this set together fine with Titebond, as I've been able to maintain very tight tolerances in the component fabrication. But I've found that I prefer slow set 50 minute Epoxy (usually a marine grade; currently using Loctite); it takes almost a whole day to reach full strength, and shouldn't be disturbed during the first 3-4 hours of setup, but it's hugely strong and stiff, and as another writer in Speaker Builder observed, enclosures seem to be tighter and deader built using Epoxy. Probably just an old wives tale, but if it feels good and you sleep better at night, why not? Subjective glue stuff, just like subjective capacitor or cable stuff. Different amine formulations work differently; this kind doesn't have the greasy surface feel of typical 5 minute epoxy, and dries rock hard. I like it... :W

Elmer's and Titebond I are kind of soft in comparison. Elmers also dissolves in water, which makes me uncomfortable- of course, MDF dissolves in water, too! Undoubtedly this is one of those things that wouldn't make it past the bean counters in a production environment. :W

It also gives you the working time you need with some decent tack when putting together a large enclosure.

[JonMarsh]

Exceedingly interested in what you come up with for that.

Should have pictures tomorrow or Friday, Paul.

These little turkey's are a lot of work- I sure hope they turn out the way I'm hoping!!

[JonMarsh]

Better known as "starburst" or "sunburst" finish.

Yeah, that looked good on my old Gibson guitars, but I'm not sure how it would work for me in a speaker in my living room. Maybe I'm just getting too old... :B
:rofl:

[BigguyZ]

But I've found that I prefer slow set 50 minute Epoxy (usually a marine grade; currently using Loctite.

I've been happy with TBIII, but where do you get the Loctite? I may take a look at that for my next project.

Thanks!

[chasw98]

For complete cabinet assemblies, with intricate construction, Titebond or Elmers won't do any gap filling with strength- not even small amounts. I could probably get this set together fine with Titebond, as I've been able to maintain very tight tolerances in the component fabrication. But I've found that I prefer slow set 50 minute Epoxy (usually a marine grade; currently using Loctite); it takes almost a whole day to reach full strength, and shouldn't be disturbed during the first 3-4 hours of setup, but it's hugely strong and stiff, and as another writer in Speaker Builder observed, enclosures seem to be tighter and deader built using Epoxy. Probably just an old wives tale, but if it feels good and you sleep better at night, why not? Subjective glue stuff, just like subjective capacitor or cable stuff. Different amine formulations work differently; this kind doesn't have the greasy surface feel of typical 5 minute epoxy, and dries rock hard. I like it... :W

Have you ever used 'marine-tex'? I have successfully used it to rebuild portions of a cast iron diesel engine block to the point that I could machine it and thread it to hold a new starter on the engine. I have also used it to repair metallic objects and then chucked it up in a lathe and cut it just like the metal it adhered to.

[JonMarsh]

Marine-Tex No, that's a new one to me!

This what you're talking about? This is the putty version.



I just love high grade epoxy, always have- I'm probably the only person on the board that digs "Epoxy Porn".

It's just amazing what you can do with a good epoxy....

[Hank]

To the tune of Wagner's "Ride of the Valkeyries": I love the smell of 3M contact cement in the morning!

[chasw98]

Marine-Tex No, that's a new one to me!

This what you're talking about? This is the putty version.



I just love high grade epoxy, always have- I'm probably the only person on the board that digs "Epoxy Porn".

It's just amazing what you can do with a good epoxy....

That's the stuff. It was formulated to make a boat work when it wouldn't and you were a long way from land. Impervious to most grease and chemicals, not to mention water. Once dry (which doesn't take too long) you can drill and tap it with fine threads.

[Johnloudb]

To the tune of Wagner's "Ride of the Valkeyries": I love the smell of 3M contact cement in the morning!

Yeah, it Smells like...Victory.

look out ... Thomas is coming.

[JonMarsh]

I don't have enough clamps....

To put together two cabinets at the same time! For some ridiculous reason, i thought maybe I did, ever the optimist. I should have known better, considering that in the M8ta I assembled the cabinet shell separately from the front, then mated the two together; in this design, the various bits are more integrated and wind up being assembled around the front panel/midrange enclosure assembly.


These cropped pictures don't really convey the forest of clamp poles involved here, but maybe that's just as well.




And looking up the bottom...



Note, the side walls are NOT double width, that's just the extra spar for stabilizing the connection of the base to the rest of the cabinet, which will have threaded inserts once it's finished. The base will include part of the port length, this ended up being a little touchier on space than I expected.

BTW, that Cardas SE-9 cable is sort of weird feeling; it's a litz coax design, with a lot of copper in the relatively small diameter, so it's heavier (in weight), than you'd expect, but due to the variable gauge Litz construction, very flexible and "limp".

Time to go build another turntable and some veneer fixtures. :W Oh, and maybe lunch, too!

Oh, and last, for those of you who enjoy this sort of thing (we KNOW who you are...), this is the calculated LF transfer function for the cabinet shape and volume and driver and port positioning and damping, per Martin King's ML-TL MathCAD worksheet for the Ardent LF configuration.




This configuration does OK at minimizing column resonances for the most part, with the results calculated here quite similar to the simpler calculation in Unibox. Hopefully the real world will be as accommodating.

[Txgrizzly]

Good googly moogly that is one thick baffle on these things... i think it would stop a 45 round fired at close range... i like the collection of clamps. i have about 1/2 that many and i thought i have alot...with all that weight on the front of the speakers you might have to bolt the back of the speaker to the floor to keep it from tipping forward... :lol:

[JonMarsh]

...with all that weight on the front of the speakers you might have to bolt the back of the speaker to the floor to keep it from tipping forward... :lol:

And that's part of why it's good they tilt back 10 degrees from the vertical.... :B

[JonMarsh]

Exceedingly interested in what you come up with for that.

I'll give you a hint or warning, it requires using these:


Bessy Strap Clamps

[JonMarsh]

Finally, something that looks like it could be a speaker someday...

You didn't ask for it, but you got it anyway- all 98.5 lb without base, drivers, crossover, or even that little dolly it's sitting on now- at least that's what my digital scale says.




At least one is looking vaguely like a speaker and the drawing on my Mac!

And is that cabinet dead and stiff! It's like pounding on a piece of granite... well, except for the MDF and epoxy fumes still. :lol: :W


Of course, CraigJ probably already has his pair done and the crossovers tuned up, but I just don't move as fast these days as I did 30 years ago!

[Paul Ebert]

How much pressure can those generate? Seems to me that you'll need more than one to get the 100 psi plus that the cold press glue requires. True? They do seem to be the way to go, but they get expensive 8O pretty quick if more than a few are needed.

[Paul Ebert]

Your bookmatched front face looks great! :T I don't think I have enough or the right sizes of veneer to bookmatch, but seeing yours, I sure wish I could.

[Johnloudb]

Oh, and last, for those of you who enjoy this sort of thing (we KNOW who you are...), this is the calculated LF transfer function for the cabinet shape and volume and driver and port positioning and damping, per Martin King's ML-TL MathCAD worksheet for the Ardent LF configuration.




This configuration does OK at minimizing column resonances for the most part, with the results calculated here quite similar to the simpler calculation in Unibox. Hopefully the real world will be as accommodating.

Jon, I am wondering why you chose to use Martin J. King's Transmition Line MathCAD worksheet. Is this because of a low tuning and having the port at the bottom of the speaker?

EDIT: I didn't know you could model ported enclosures with his worksheets. Is his software an option to Unibox?

[Curly Woods]

How much pressure can those generate? Seems to me that you'll need more than one to get the 100 psi plus that the cold press glue requires. True?

Required pressure for proper veneering is 14lbs PSI or 2000lbs per square foot with urea type glues, which are preferred by most veneer specific applications.

[JonMarsh]

How much pressure can those generate? Seems to me that you'll need more than one to get the 100 psi plus that the cold press glue requires. True? They do seem to be the way to go, but they get expensive 8O pretty quick if more than a few are needed.

Two things-

One, the strap clamps are only going to be used for the upper and lower facets, and the top bevel.

Two, I see that 100 psi number bandied around a lot of places, particularly on the sides of bottles of glue, but a really good vac bag can't typically do more than 12-14 psi (atmospheric air pressure, remember? ), and that's typically more than enough- especially if you've got reasonably flat veneer to begin with.

I have some quilted maple for the top that will be a little more trouble, but then the top area isn't so big- and I plan on doing straight clamping with a pressure plate.

Now, obviously, my approach so far is a skosh unorthodox, but as long as it works out in the end, then I'd say it's justified, especially given the relatively low up front cost (no extra equipment to speak of) and the ability to work fairly confidently with solid wood veneer.

Just stay tuned to this bat channel and you can see without any risk (to yourself!) in the very near future whether I go down in flames or not.

The scary and exciting thing about a project when it gets to this point is that the end is in sight, and the realization of the original vision becomes more palpable- BUT!! The opportunity for "catastrophic yield loss" is high at this point- have to work carefully and with premeditation- thats why I did a test run on the finishing technique I figured to try earlier this week. Better to screw up on a cut off scrap then on a speaker with many tens of hours invested.

Well, good news is I've got the second cabinet glued and clamped up- tomorrow AM I should be able to take the clamps off, and start on some of the detail prep work.

[JonMarsh]

Jon, I am wondering why you chose to use Martin J. King's Transmition Line MathCAD worksheet. Is this because of a low tuning and having the port at the bottom of the speaker?

EDIT: I didn't know you could model ported enclosures with his worksheets. Is his software an option to Unibox?

As you probably know, Martin just very recently decided to try licensing his MathCAD sheets again to DIY users- for a while there, because of problems with folks not observing the "license", and sharing when they weren't authorized to, he shut down making them available.

The ML-TL sheet can be used for ported cabinets- as Martin calls it, one variant of his TL stuff being a 1/4 wave TQWT.

Martin goes a step further than tools like Unibox, supporting modeling of the physical layout of the enclosure and drivers- so to physically define a ported box example, you specify the internal length and width at the top, the same for the bottom, the height of the cabinet, the Z height of the driver, the Z height of the port, and the damping.

I'd only seen a couple of his MathCAD files many years ago, and when I went a year ago looking for them, he was shutdown on distributing them. Now he's got new versions available for a yearly fee of $25 for any of the MathCAD docs, including TL/Ported box, and dipole versions that he developed with John K (the other one, not Krutke). I was still curious to look at this and see how it would model with this tool- believe me, I was able to come up with some configurations that don't look so nice in some regards, due to column resonance and the location of the woofer in the cabinet can be critical.

An interesting tool- I've been a MathCAD user since the DOS version in the late 80's, so this is my preferred way of doing things, not Excel. :W

[Txgrizzly]

98lbs without the guts, drivers or base... you are going to have to hire moving guys just to get them out of your shop and into your house....

[Hdale85]

Wow that cabinet looks fantastic!

[JonMarsh]

Fortunately for me I'm 6'2" and about 220 lb- I have friends, and my boss at work, that couldn't possibly move these on their own. My limit is somewhere around 150-190 lb. :W

[JonMarsh]

Wow that cabinet looks fantastic!

Thanks, Dougie- I hope it looks a lot more fantastic than this in a couple of weeks or so!

[fjhuerta]

This thread is better than sex.

I hope my wife never reads this post.

[Hdale85]

I hope when I get around to trying to build these they come out as nice. I doubt it though.

[cjd]

Jon,

Your glue-work is sloppy and the braces aren't perfectly lined up! What's up with that?!

(just figured we needed to deflate your ego a bit here after all these compliments... :P )

[JohnA]

I just love high grade epoxy, always have- I'm probably the only person on the board that digs "Epoxy Porn".

It's just amazing what you can do with a good epoxy....

Yes count me as another, that is amazed by what can be done with epoxies.
Some of the things you can do with using epoxy during restoration work, can be big money and time savers! I have used epoxies that range from water thin to thick paste/putty versions, and just about every viscosity thats in-between them to do wood restoration.


Here is a good source for all sorts of epoxies, and at some very good prices. This is their entire line of products. And also quite a bit of info about epoxies. It's a bit hard to navigate through it, but they do have a lot there.

http://www.epoxyproducts.com/

This is the exact same place, the big difference is they do not show all of their available products on this much simpler to navigate storefront.

http://www.epoxyusa.com/default.asp

[Dave Bullet]

This thread is better than sex.

I hope my wife never reads this post.

Sex? - what is this thing they call sex? I've been too busy reading this post.

As for Jon's biometrics... sounds like he's modeling the enclosures after his own form. A monument if you will.

[JonMarsh]

Jon,

Your glue-work is sloppy and the braces aren't perfectly lined up! What's up with that?!

(just figured we needed to deflate your ego a bit here after all these compliments... :P )

Always I can rely on you to be the voice of objective reason and to set the bar where it really belongs! :agree:

Good thing I have the parts cut and collected for the second pair with Dayton and Seas Drivers (actually, either set can be mounted- there's no difference in the cabinet design), so I can apply "lessons learned" in the future.

While you're rightfully holding me to account for the sloppy glue work and the less than stellar precision on the line up of the braces, I'm just dead relived that it did all go together in a relatively straight forward manner with just one set of hands! Undoubtedly I'll be hearing some critiques since I didn't capture the process on digital film, or any other kind! :W

This design was a challenge because of the midrange enclosure and because of how I wanted to simplify the braces. This made it unfeasible to assemble the cabinet shell first as a separate item the way I did with the M8ta. Several things were necessary to make it "doable" by one person.

First, the midrange enclosure was glued to the front panel, and the board heights on the struts reaching the back carefully sized to have a small gap ( I mean "small"!) to allow for a thick epoxy, but not to prevent flush seating of the back panel.

Second, biscuits were used to align the side panels with the side edge of the front panel, and to align the top panel to the upper edge of the side panels- with proper fabrication, these parts became self aligning that would otherwise be a nightmare to keep straight during assembly. Kudo's to Bosch Biscuits, those little marvels of Deutches precision and quality- high grade workmanship on a relatively small level. My favorites after trying several other name brands, including PC.

Third, the back panel design uses the two part 90 degree dado design as well as a routed channel for the center brace to aid alignment, provide for a flush fit (with good fabrication workmanship), and help it go together quickly. Everything has to be sized correctly and lined up religiously during assembly for this to work, though. The pre-glued side braces stay perpendicular to the sides and also force the center brace into alignment with the rabbeted channel in the back; the channel is a special 13/16" bit design for this sort of application, as a channel for 3/4" boards.

Two kinds of 50 minute epoxy were used; the Loctite marine grade which is much thicker, and can be layered on and doesn't run off the end of a board, (used on the midrange enclosure, on pre-gluing the side braces to the side panels, and for gluing the center brace to the front panel, midrange enclosure, and to the back, and the front of the top panel to the front panel (here mostly for it's non-drip properties)), and a more conventional consistency standard 50 minute 1product that comes in dual 4 oz bottles, and was used for the long seams of the sides to front panel, sides to top panel, and sides to back panel.

The assembly was done in a wrap around fashion, starting with the center brace to the front panel and midrange enclosure, and adding one side panel, adding the top panel with a set of light clamps (Erwin) to hold it in position (after aligning position along the long axis so the top panel/side panel assembly is flush with the top of the front panel) while gluing up the second side panel and moving it into position, while transferring the light clamps to hold both sides against the top panel (alignment provided by biscuits, remember). Last, the epoxy was applied to the surfaces of the side panels and top panel mating to the back panel, and the back panel is dropped into place, then aligned along the length to the top panel (which has previously been aligned to the front), then everything is clamped down, using my painter polyethylene sheet as needed to prevent epoxy seepage from gluing the clamps to the cabinet.

It took a little thought to come up with a design and process that I figured was doable with good precision with just a single set of hands- the anticipation and tension the night before yesterday (before when I tried out the assembly) was as palpable to me as the night before Christmas when I was a kid.

Well, next we'll work on cleaner glue work during assembly and trying to figure out a better way to align the braces- though since no one can see them after it's put together, maybe I'll just let this one item slide for now... it can be our little ugly secret!

[savage25xtreme]

And looking up the bottom...

what is the purpose of the gap on between the sides and back? just not squeezed tight in this pic?

[JonMarsh]

It's a shadow /epoxy line; plus the sides are just a teensy bit long, (but only towards the bottom), and will be trimmed using the sliding miter table (we're talking about a 1/16" of an inch here.

[savage25xtreme]

ahh I see it now... thanks

thought you were up to some kind of trick I needed to learn about :B

[JonMarsh]

Yes count me as another, that is amazed by what can be done with epoxies.
Some of the things you can do with using epoxy during restoration work, can be big money and time savers! I have used epoxies that range from water thin to thick paste/putty versions, and just about every viscosity thats in-between them to do wood restoration.


Here is a good source for all sorts of epoxies, and at some very good prices. This is their entire line of products. And also quite a bit of info about epoxies. It's a bit hard to navigate through it, but they do have a lot there.

http://www.epoxyproducts.com/

This is the exact same place, the big difference is they do not show all of their available products on this much simpler to navigate storefront.

http://www.epoxyusa.com/default.asp

Thanks for the links, John!