I happen to have some urethane caulk on hand so it's getting messy. It's hard to get the curves right so I am infilling with caulk. Dirty, dirty, my Mother used to say.Nice work Cal! Why is it less fun than Cornu? Looks like fun to me.
Thanks Ken, I sure hope it sounds good too.
As mentioned many times, the credit really goes to X, he's the one who started this craziness, I am just following in his footsteps.
Cal,
Why did you have to resort to caulking? Couldn't hot melt to tack and a bead of PVA to seal have worked? I agree that grey caulking is a mess especially if it is silicone. I was thinking about the curves you put in after the main channels - are they really needed? They will improve efficiency but may reduce the effectiveness of those sharp bends to act as low pass filters to keep the HF stuff from getting out. Anyhow, this is a really cool and unique design and I am really excited to hear your first listening impressions. Nice work with the channels - the photo of the central chamber with curved throats leading out is really cool and epitomizes the advantages of working with foam core in rapid prototyping. Very nice!
Why did you have to resort to caulking? Couldn't hot melt to tack and a bead of PVA to seal have worked? I agree that grey caulking is a mess especially if it is silicone. I was thinking about the curves you put in after the main channels - are they really needed? They will improve efficiency but may reduce the effectiveness of those sharp bends to act as low pass filters to keep the HF stuff from getting out. Anyhow, this is a really cool and unique design and I am really excited to hear your first listening impressions. Nice work with the channels - the photo of the central chamber with curved throats leading out is really cool and epitomizes the advantages of working with foam core in rapid prototyping. Very nice!
Hot melt was only for the tacking but PVA wouldn't work on the vertical joints and it really is too slow to set up. That would drive me crazy, my time is limited and I'm a naturally impatient person.
Far worse than silicone, it's urethane.
In my mind I am happier with the curves although you may be right.
Me too, fingers crossed. It is many days away though.
Ya, watching it come together is still really satisfying.Nice work with the channels - the photo of the central chamber with curved throats leading out is really cool and epitomizes the advantages of working with foam core in rapid prototyping. Very nice!
Check out this site for all types and sizes of foam board materials.
foamcore | foamboard | foam board | gator board | self adhesive
They even have special cutters available.
foamcore | foamboard | foam board | gator board | self adhesive
They even have special cutters available.
I finally got to see an example of 0.5 in black Gatorboard: it is very nice - flat like a sheet of granite and stiff and strong like good plywood, but light like foam board. They use it at my work to mount big promotional posters and PR material. It seems to be more expensive than BB plywood but I see why - it is closer to an aerospace grade honeycomb structural panel than anything I have seen. You could make an airplane out of it. It would make an awesome and lightweight speaker enclosure. But way pricey... I will have to try home insulation foam sheathing next at $10 for 4x8 ft.
There's a thread on here about (commercially produced) speaker enclosures made of lightweight but stiff panels, using damping materials to move the resonances to where they are less objectionable.
http://www.diyaudio.com/forums/mult...ad-i-found-lossy-cabinet-designs-harbeth.html
http://www.diyaudio.com/forums/mult...ad-i-found-lossy-cabinet-designs-harbeth.html
Hey Cal,
I believe this was mentioned earlier, I think by you even, but when I built my set, to combine the strips I cut behind both sides of the paper, folded them over, cut out the foam, and then glued the paper to the next strip. Kinda like a Sheetrock butterfly patch. It looks like you could do the same on those tight corners.
Like I said, probably already discussed. I feel bad for ya though, you are more than likely looking at the belt sander thinking this is the only way to get this stuff off my hands. On a side note, wear rubber gloves when using door and window expanding foam!
All aside, those look awesome.
I finished my uFonken in Foam Core, go to this DIY Audio thread (Page #6 - Post #53) to see my quick opinion and pics.
Guangui,
Those look good in that finish and I am happy the sound worked out even though this was designed for the much more expensive FF85wk. Those are the same binding posts I use!
Thanks! I am very happy with the result of using the inexpensive TB W3-881SI.
Hi Zayne,
That's a great idea., I will have to remember that for next time. Next time? OMG - Gulp!-
I have now completed the internal channels and after cursing the caulk up and down, I decided to read the label. You know how you assume sometimes? Turns out this isn't urethane, it's butyl caulk meant for gutters, not the stuff for vapour retarders, so I really did curse myself. If had only run to the store for some of that cheap acrylic latex stuff, I would be a lot happier.
So now I am ready to install the backs. Because this is a critical one to seal up tight I will employ the filet method where you glue down a thin strip of paper first to give me a level ledge onto which I can add a heavy layer of PVA for the bonding.
There is light at the end of the tunnel!
Looks to me like a new page for the Rorschach test. If you see a snowflake you are normal and sane. If you see four tiny tubas you have an advanced case of FC syndrome.
You mean Five tubas - I guess you have it worse than you think?
