Foam Core Board Speaker Enclosures?

Tapered walls, bottom mounted PR and a 3 sided plinth. Semi slot loading.
Sounded like a TV speaker. PR movement too restricted.
Pulled the PR's and left them running while deciding what to do. Whoa, what's that I hear? Stuff a towel in there and you know what? That sounds ok.
Damn, that wasn't supposed to happen.
OK, only one solution for this mess. Bi-amp.
They are in the same cavity at this point but they really do sound good when xo'd at 100Hz. Good enough for me to keep playing.
 

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Founder of XSA-Labs
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Sorry it did not work out Cal. But you have yourself a FAST now. I recall there was a thread where two different drivers shared a common chamber - it actually had benefits.

Your JVC may be of limited excursion and fs too high to couple well with the PR’s. Something like those Nd full range with aluminum cone and lots of Xmax might work better with a PR.
 
hehe. Thanks JW.

Just to clarify, it did work out. With the woofers being used as intended and the 100Hz cut off on the JVC's, these things can tick off your neighbours right proudly.

Yes X, although the Xmax is greater than the Vifa, it still may not be enough to get those Reckhorns moving. That cone is just too heavy and the suspension too stiff. Good for a down-firing PR but alas, all the things I was looking for added up to too much of a good thing. The cabinets are well sealed judging by the 'push and hold the PR' test.
The Reckhorns are an enigma. They are a low sensitivity, low Q, high transient response woofer. Tremendous overhang yet a tight suspension. Go figure why they never made it in the market. You need a tank of an amp for a 13cm woofer. :)
 
Tapered walls, bottom mounted PR and a 3 sided plinth. Semi slot loading.
Sounded like a TV speaker. PR movement too restricted.
Pulled the PR's and left them running while deciding what to do. Whoa, what's that I hear? Stuff a towel in there and you know what? That sounds ok.
Damn, that wasn't supposed to happen.
OK, only one solution for this mess. Bi-amp.
They are in the same cavity at this point but they really do sound good when xo'd at 100Hz. Good enough for me to keep playing.

Nice build!
 
Many years ago, I built two modified Carlson cabinets using Styrofoam panels and white glue. The panels were 1 inch thick and I was using a single 8-inch full-range driver in each cabinet. The panels resonated a lot, adding midrange coloration and weakening the low bass. It was quick, cheap, and convenient, but not sonically successful.
 
Good question...

Thanks for asking about the braces. No, I was young and naïve in those days, and did not think about braces. One thing I remember about the project was that, to my surprise, the simple white glue joints (Elmer's) seemed actually stronger than the foam panels themselves. The drivers were Polyplanar, if you are familiar with those: flat Styrofoam "cones," so at least there was consistency of material between the drivers and the cabinets.
 
One thing I remember about the project was that, to my surprise, the simple white glue joints (Elmer's) seemed actually stronger than the foam panels themselves.

That's true for many other materials. Glue is strong.

This chap has tips on building with foam, that include scoring the foam surface, increasing the area that is in contact with glue, which makes that interface better (less likely to tear the surface layer off the foam).
Seafoam Kayak, the Unsinkable Foam Kayak Anyone Can Build, 16 Pounds and Eight Feet of Fun

Putting a stiff skin on the foam also makes the structure (much) more rigid; most surfboards are a fibreglass skin over foam.
 
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XPS Kayak made with bedsheets and Titebond! Very cool, but you can also buy a brand new injection molded 8ft 27lb kayak with seats, stowage compartments, etc and probably faster and more durable for $180. 8ft sheets of XPS not cheap, plus gallon on Titebond, and 3 tubes of PL premium, plus paint, misc hardware, etc probably about $100+.

Pelican Trailblazer 100 NXT Kayak | DICK'S Sporting Goods
 
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Very cool, but you can also buy a brand new [...] 8ft sheets of XPS not cheap, plus gallon on Titebond, and 3 tubes of PL premium, plus paint, misc hardware, etc probably about $100+.
Good guess :)

The DIY guy:

a) states the cost as "roughly $100 US"

b) also makes a 12 foot kayak that he has "ridden in some rather rough surf with no issues", and his 12 foot kayak is the same weight as that commercial 8 foot craft you linked - so he is getting some return on his labour (other than the pleasure of creation).

I don't know much about kayaks, but I gather that a good weight:size ratio is important. I think you get less drag / go faster when you sit higher in the water.
 
Hey xrk971, it's been a while.

I still have that Encore X-LS speaker kit sitting on the shelf -- thanks for that recommendation.. it's been way over a year I think. I so want to test them out but I've been putting it off because I dread all the MDF cutting and gluing and what not.. and then the veneering.

I was thinking it'd be nice to pay someone to make pretty cabinets for these with some nice veneer and finish. Don't know how much one would charge to do that.

Should I try them out with cardboard or foam? How's that been going for you? I could glue multiple layers of cardboard with white glue .. so easy to cut out with knife. Then I can sand/fill, paper mache or whatever .. and then paint with a pattern or something by hand to make them look cool. Just wondering if they'd sound as good as if they were in MDF. I really want to see what my LM3886 , B1 Buffer and turntable sound like with them.
 
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Hi JenniferG,
Try 1in thick XPS foam insulation. Brace it well. It sounds almost as good as plywood. Add 3/16in subfloor ply for the baffle so the screws have something to hold.

Sort of like what I did here:

10F/8424 & RS225-8 FAST Ref Monitor

Those XL-S Encore are nice speakers. That would be a waste to let then sit on a shelf as parts and pieces.
 
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