I've had a (possibly insane, though probably not really considering the use of CNC in this thread!) different idea on how to tackle the project, using the original spiral design, rather than the "squared-off" one.
I'm actually going to use the original spiral design, but was having some problems with the scale of my printout.
So, I've taken the original PDF, and turned it into a SVG image, so that scaling (hopefully) works a little better. I've attached it here, and I'll let you know if it works tomorrow, as I don't have a printer at home.
It's great to see such a versatile design!
I'm actually going to use the original spiral design, but was having some problems with the scale of my printout.
So, I've taken the original PDF, and turned it into a SVG image, so that scaling (hopefully) works a little better. I've attached it here, and I'll let you know if it works tomorrow, as I don't have a printer at home.
It's great to see such a versatile design!
OK, I'm jumping on the picky wagon here Don. A Cornu or any version of it has one driver and 2 sets of horns of unequal length in a squared off spiral. Anything else and it gets it's own name. Lots of possibilities with spiral horns and I think that's what you meant. Bose has a patent on a 2 spiral horn and there is a plan here for a 6 spiral. Heck some dummy even bent the spiral into a Penthorn and still wants to be included in the group. Can you believe some people?
What's in a name?
The reason I suggested a spiral horn profile is that it works well when building in foam board. (No large flat unsupported surfaces.)And, strictly speaking, the "Cornu" as used here doesn't have a Cornu law profile. As pointed out earlier in this thread, it's actually an exponential horn. And in simulation at least, the unequal length horns don't really have any advantage over single length. But given the amount of pleasure people are deriving from building and listening, it would be churlish of me to point this out.
What do you use to view the SVG file? Adobe PDF is in fact a vectorized graphics drawing and can be scaled without loss of resolution.
Hi, i just started this game and i am in the process of planing a 70*70cm model. I was wondering a few things. I am planing on using the Fostex FE108E. I plan on making it 14cm deep. As i understand it the throat, mouth and the coupling champed is the most important factors. Is there anywhere these standard facts are organized, where can i find the numbers for this?. Also i am only planing on making it a single layer. Does that have any effect on the design. I am using the design from this site. Do i even have to think about the design or could i just use this and make it? Thanks
The FE108E is a good driver for the Cornu. I would make it about 11 to 12 cm deep. Just follow the PDF plan scaled down and you ate good. Put stuffing in driver chamber and you can always add more in throats later. It is a very forgiving design so don't worry and have fun building. Make sure you score the channels to bend them into curves. Glue sections at a time and do final capping glue operation with PVA white glue. I think the single channel actually provides better deeper bass as the circumference of the horn mouth is larger this way.
Good luck!
X
Heck, some dummy even bent the spiral into a Penthorn and still wants to be included in the group. Can you believe some people?
Hey Don? That dummy is me. It's all in fun.
Unless you try and change the name that is...
The throat isn't too sensitive as long as you are in the right ballpark by setting the depth correctly.
Thanks Cal -
The price for the TB is back up to ~$300/ pair, money I would rather spend on electronics.
I am still looking for the best t-amp which can run on 12v, and an RCA input source selector. This system will be in a mountain cabin, off the grid, and run on a car battery.
Phono, CD, and Ipod in will be the sources. I have the Bedini tube phono stage which runs on 12v.
Should be a respectable little system to replace our D battery eating plastic boom box from the 90s.
Should I line the interior of my horns with fabric of some kind? At least the inner sections? (In addition to a wad of lambs wool in the chamber).
Will post pictures when I am a bit further along.
Colin
The price for the TB is back up to ~$300/ pair, money I would rather spend on electronics.
I am still looking for the best t-amp which can run on 12v, and an RCA input source selector. This system will be in a mountain cabin, off the grid, and run on a car battery.
Phono, CD, and Ipod in will be the sources. I have the Bedini tube phono stage which runs on 12v.
Should be a respectable little system to replace our D battery eating plastic boom box from the 90s.
Should I line the interior of my horns with fabric of some kind? At least the inner sections? (In addition to a wad of lambs wool in the chamber).
Will post pictures when I am a bit further along.
Colin
Colin,
The tpa3116d2 thread
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp.html
has lots of good info but here is to link of amp for sale.
Online Shop TPA3116 Amplifier Board(50W+50W ) D Class Amplifier Board|Aliexpress Mobile
The tpa3116d2 thread
http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp.html
has lots of good info but here is to link of amp for sale.
Online Shop TPA3116 Amplifier Board(50W+50W ) D Class Amplifier Board|Aliexpress Mobile
Cheap and good sounding source switch is an RCA patch panel
. Hey it works, is cheap, and you can't beat the sound quality!Maybe it was the way that the printer was configured at work, but the outer straight lines of the paths only created an 18.9" square. Maybe I've misunderstood, and in that case does that mean that the pattern is 'inset' into a 20" square?
I've printed the SVG I'd done, and it came to a 20" square. However, I have enough doubt in my mind now to not proceed until I'm sure. I'm always a bit wary of the accuracy of multi-page printing
Hi again. I found out that i can make it a lot easier if i scale down my cornu all-wood project down to 60*60cm around 24 inches. (I use the sebastian design seb:diy:audio: Cornu Spiral Copy Horn) Is it possible to use this design with the Fostex FE108EZ driver? Altso should i chance the throat and depth in the design.
PS. I was thinking of using double-3mm mdf as the spirals as it very bendable, could this work?
Thanks
PS. I was thinking of using double-3mm mdf as the spirals as it very bendable, could this work?
Thanks
The Sebastian Cornu site is based on the full size 70cm size which was designed with the FE108E Sigma in mind. You could scale it to 24 in and lose some bass extension but it will work. 24 x 5 in deep should work fine. A Tang Band W4 bamboo cone works very well at this scale and has been proven to sound good by Prezden. Costs a lot less and has more xmax for fuller bass.