Hi Cal. I'm good. Glad to see you guys are still alive, kicking, and pushing the boundaries of DIY audio.
Instead of a dado/slot/channel in the sides I just meant cut straight through the foam so you have a slot to put the wall into. It appears that I need to research the history of the Cornu a bit more.
I've used this stuff before to make architectural models and it's nice to work with. You can get fancy with tools that let you cut nice angles but as you have shown you can get great results with minimal effort just using a straight edge and a knife!
Cal,
I think it's a great idea and in fact I suggested it a few posts back. So did Kenlbird. It's pretty inexpensive and big. Use framing adhesive?
R-Matte Plus 3 R-3.2 1/2 in. 4 ft. x 8 ft. Foam Insulating Sheathing-754404 at The Home Depot
You can make a full size BIB for 8 in driver with it or a HT tapped horn sub.
I think it's a great idea and in fact I suggested it a few posts back. So did Kenlbird. It's pretty inexpensive and big. Use framing adhesive?
R-Matte Plus 3 R-3.2 1/2 in. 4 ft. x 8 ft. Foam Insulating Sheathing-754404 at The Home Depot
You can make a full size BIB for 8 in driver with it or a HT tapped horn sub.
When you say clamshell do you mean drivers are inside between two chambers with vent on one side? A 4th order bandpass sub cabinet?
I just designed one today with the Aura 6 in NS6 closeout woofers $9 ea. Flat bandpass from 40 to 100 Hz with 87 to 89 db efficiency in box 8 x 12 x 24 in. Perfect for foam sheathing.
I really wonder if that will work, here comes Mr. Downer, all of the thick insulation I have used, usually the pink 3/4", has had a strange resonance. Now I did not use it for any cabinets, thought about it. But when handling it, it just seems like it's natural resonance would cause issues.
I hope I am wrong! If you get a chance go pull a piece off the shellf and thump on it a bit.
Will work best overall with high Q drivers to help damp their inherent 'ringing', but bracing goes a long ways towards stiffening it up if using a lower Q driver.
One of many published fun projects from the early days of engineered insulation board that helped fuel my interest in DIY speaker design: Weems Celotex TL - a set on Flickr
GM
You're welcome! Unfortunately not since '72 and wouldn't have this one except for FreddyI and IIRC he didn't still have it either. All I remember is it's similar/smaller. Regardless, with MJK's, etc. software one can design something similar and/or better overall, I just haven't gotten around to it.
In retrospect and with a lot better understanding of such things, virtually all the published DIY projects I built or more recently reverse engineered requires anywhere from a ~0.7-1.2 Qt system, so the Bofu would need ~3-8 ohms of series resistance.
GM
In retrospect and with a lot better understanding of such things, virtually all the published DIY projects I built or more recently reverse engineered requires anywhere from a ~0.7-1.2 Qt system, so the Bofu would need ~3-8 ohms of series resistance.
GM
The first speaker project I built was the David Weems 8 inch Celotex corner enclosure in the November 1955, issue of Popular Electronics. I was fifteen at the time and I remember the trouble I got into for building it in my mother's kitchen. I used a speaker from a junked Zenith TV along with my ten watt Allied Radio Kit amp. Over those last six decades I built a number of his designs and in 1992 I wrote him and received a reply. We corresponded over the years and when I retired back to my native Missouri we finally met. I interviewed him for an article that appeared in the October 2009 issue of Audio Express. We spoke a few days ago and he doing well at age 91. I have many of his designs in PDF form from 1955 to 1970 that appeared in popular Electronics and Radio Electronics. He is truly the father of DIY speaker building.
See the pic. If you place another driver on the opposite side of where the driver is shown in a normal tapped horn and face it together it's called clamshelling. It's a type of isobaric loading. It allows for the downsizing of the cabinet by approximately 1/2. I wonder if it would work.
Me too but let's not forget the two products are different. the pink stuff is unfaced Type IV EPS made by Owens Corning. This is a faced iso board so I dare say the two are going to behave differently.
Attachments
Cal,
Thanks for enlightening me on isobaric driver arrangement! I was telling you about the 4th order bandpass subwoofer I was designing in WinISD and went in there and turned the "clamshell" switch to ON and sure enough the enclosure achieved better performance at half the volume! Pretty cool.
Thanks for enlightening me on isobaric driver arrangement! I was telling you about the 4th order bandpass subwoofer I was designing in WinISD and went in there and turned the "clamshell" switch to ON and sure enough the enclosure achieved better performance at half the volume! Pretty cool.
Well, since I don't have any software how do you feel about this? 
http://www.diyaudio.com/forums/subwoofers/229628-isobaric-tapped-horns.html#post3361631
http://www.diyaudio.com/forums/subwoofers/229628-isobaric-tapped-horns.html#post3361631
You can read about them in the other thread. I would like to downsize a bit and having them concealed in the cabinet works for me also. Size would be about...
...let me go home and I'll give you the measures of the cabinet they are in now. I would like to reuse it.
The upper cabinets are the RS-1354 5.25" and a HiVi dome tweeter XO'd really high.
...let me go home and I'll give you the measures of the cabinet they are in now. I would like to reuse it.
The upper cabinets are the RS-1354 5.25" and a HiVi dome tweeter XO'd really high.