I was wondering about a different glue also. Sub-floor or Construction comes to mind but I wasn't sure about how to make it work, and it wouldn't dry clear either.
You can get Bendy-Ply rather than the MDF stuff, so there is no kerfing. Not sure it would be as easy as the foam though.
http://www.plytech.co.nz/userDocuments/SpecSheets/Bendy_Ply.pdf
You can get Bendy-Ply rather than the MDF stuff, so there is no kerfing. Not sure it would be as easy as the foam though.
http://www.plytech.co.nz/userDocuments/SpecSheets/Bendy_Ply.pdf
Ya, I thought it would get more interest here. We have moved past the Construction part and are into the actual projects. Later I might split mine off or even do a step by step project thread. We'll see, it depends on how well they come out, right? 🙂
The Son of Cornu
OK, I am getting restless not having held a hot glue gun in my hand for over several days now. Sounds like an addiction... I have an idea to try out the Cornu spiral on a smaller scale with 2 inch drivers. In fact, I will be cannibalizing a cheapy set of Logitech S-120 computer speakers with what appears to resemble a Visaton FRS 2-inch fullrange. It is labeled 5W 4 Ohms on the back and actually looks pretty decent. I plan to drive it with the Logitech chipamp that came with the speakers (probably 3 W/channel). I will shrink the Cornu plan down to circa 14 in square x 2 in deep and mount these on the wall next to my desk as the ultimate compact fullrange PC speakers. I am laying out the plan now, it looks like I can get a 43 in long and 28 inch long channels in a 14 in square. This will give me tuning frequencies of 74 Hz, and 120 Hz, respectively. We will see how much bass enhancement below 120 Hz I can get with these beauties... If this works out, it might be a little easier and more of a starter scale project for those intimidated by the full scale Cornu spiral that Cal took on by the horns.
OK, I am getting restless not having held a hot glue gun in my hand for over several days now. Sounds like an addiction... I have an idea to try out the Cornu spiral on a smaller scale with 2 inch drivers. In fact, I will be cannibalizing a cheapy set of Logitech S-120 computer speakers with what appears to resemble a Visaton FRS 2-inch fullrange. It is labeled 5W 4 Ohms on the back and actually looks pretty decent. I plan to drive it with the Logitech chipamp that came with the speakers (probably 3 W/channel). I will shrink the Cornu plan down to circa 14 in square x 2 in deep and mount these on the wall next to my desk as the ultimate compact fullrange PC speakers. I am laying out the plan now, it looks like I can get a 43 in long and 28 inch long channels in a 14 in square. This will give me tuning frequencies of 74 Hz, and 120 Hz, respectively. We will see how much bass enhancement below 120 Hz I can get with these beauties... If this works out, it might be a little easier and more of a starter scale project for those intimidated by the full scale Cornu spiral that Cal took on by the horns.
That warms my heart - my dad had 10 or 12" speakers in cardboard boxes in the basement shop when I was a kid and for low power classical music on the radio, they sounded absolutely good enough. This memory really makes me want to do this.
I think there isn't a speaker DIY'er out there who hasn't cut a hole in a cardboard box just to see what it sounds like - and as we know... it can sound pretty good! The foamcore board is the next step up to give it more shape so you can control geometry better, and thus better sounding, and it looks better. I still have a cardboard box (covered in vinyl contact paper) transmission line that I use everyday in one of the bedrooms with the mp3 player.
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i was wondering if coroplast (like corrugated cardboard only plactic) would work as i can can't seem to source the foamcore board
I think that would be hard to work with and a lot more expensive than the Dollar Giant stuff at $1.25 per board. Google Dollar Giant or Dollar Tree and find one close to you. Took a couple of tries before I found a store that had it though. I didn't bother calling because even when I found it, the lady at the front said they didn't have anything like it.
Not good. I plugged your location into Dollar Tree website and it says you don't have one very close. Can you confirm this at your end?
Try the crafts or stationary/office supplies sections in other chain stores like Michaels, Walmart, Office Max, Staples
etc. I have even seen it at my local supermarket. The cost may be higher than the dollar stores though. Any place that does posters or signage will have it too.
etc. I have even seen it at my local supermarket. The cost may be higher than the dollar stores though. Any place that does posters or signage will have it too.
'round here the "buck or two" stores carry stuff called fun foam but it's only 1/8" thick and 16X20 inch sheets. i wonder if other craft supply stores like michael's might stock the foamcore board.
Simply put, no. It would be much more difficult to work with.
Now, it WOULD make a great baffle material if you laminated layers of it- you'd have to seal the edges though so as not to have a leakage path.
Here's a real crummy mock-up of the Fostex BK-10 I've built a couple of years ago:
IG
An externally hosted image should be here but it was not working when we last tested it.
IG
thanks xrk971
i was just composing my last post when i seen your post pop up. i think a trip to micheal and walmart are in my near future.
i was just composing my last post when i seen your post pop up. i think a trip to micheal and walmart are in my near future.
From memory and then only a brief listen back then, sounded OK, though I felt some mid-bass was lost making the whole thing vibrate. I did not brace it more than what the internal foldings provided. Buying a butt-load of foamcore sheets, laminating 3 or 4 thick might be decent enough for low levels. I get these in 20" x 30" formate in dollar stores, ~1.50$ each IIRC.
IG
I would not be so quick to dismiss this material without first trying it. It may be difficult to cut but if you had a way to cut it, hot melt would glue it just fine. Elmer's glue of course won't work. I think there is potential here. You can even fill the channels with sand and seal off with hot melt glue to get good damping on certain surfaces like front baffle. It will probably cut easily with hot wire cutters. Tin snips would work but leave an ugly edge.
Cross-laminating corrugated cardboad would be an easy way to get more rigidity, like plywood...