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Old 17th September 2013, 12:14 PM   #1001
Coen is offline Coen  Netherlands
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Quote:
Originally Posted by Vix View Post
Coen, it would be nice if you could make and post photos of work-in-progress of this one.
Me, I don't need another set of speakers at this time, (no space) but this one may be hard to ignore. I was just staring at a blank wall in my bedroom and thought "why not...."
Hi Vix, ofcourse i'll post some work in progress pics.. i just hope glueing this thing won't get to messy
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Old 17th September 2013, 12:52 PM   #1002
xrk971 is offline xrk971  United States
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Default Sim of Cornu with FE85

Quote:
Originally Posted by Coen View Post
I've decided to go with the Fountek FE85
Coen,
Here are sims of the Cornu with the driver you have chosen. It can work reasonably well in a Cornu ranging from 20 in to 24 in x 2.5 in deep. The bigger, the deeper the bass. I would go with the biggest you can. The 24 in will reach down to 60 Hz.
Regards,
X

20 in x 2.5 in deep:

Click the image to open in full size.

22 in x 2.5 in deep:

Click the image to open in full size.

24 in x 2.5 in deep:

Click the image to open in full size.

Impedance of 24 in:

Click the image to open in full size.

Cone Excursion of 24 in:

Click the image to open in full size.

Good luck with your build! It will sound great.
Attached Images
File Type: png Cornu-20x2p5-FE85-Freq-1m.png (28.5 KB, 563 views)
File Type: png Cornu-22x2p5-FE85-Freq-1m.png (28.5 KB, 562 views)
File Type: png Cornu-24x2p5-FE85-Freq-1m.png (28.7 KB, 562 views)
File Type: png Cornu-24x2p5-FE85-Impedance.png (23.2 KB, 562 views)
File Type: png Cornu-24x2p5-FE85-Displ.png (22.0 KB, 560 views)
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Old 17th September 2013, 03:10 PM   #1003
Coen is offline Coen  Netherlands
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Hi X,

Thanks for the simulation! i was planning on doing a full foam speaker but the boards are only 50cmx70cm, to get 24 inches i'd need to paste them together or use multiplex / mdf for the back and front.

Btw what sort of glue is everyone using for full foam or foam/wood? should i think of buying a glue gun or just get something like gorilla glue?
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Old 17th September 2013, 05:15 PM   #1004
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Use a half sheet of ply and make the box 23.75"

Use hot glue for gluing the first side and plain white or yellow glue for the second.
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Old 19th September 2013, 03:35 AM   #1005
prezden is offline prezden  Canada
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A while ago I built a pair of 22" spirals with TB W4 bamboo drivers for a friend. Well I got to sit and listen to them properly set up in his house today. We were both blown away by the sound after listening to some Bill Evans, Chick Corea, Sarah Brightman and a couple Shostakovich string quartets. These speakers sounded great with everything we played.

cheers
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Old 19th September 2013, 09:56 PM   #1006
xrk971 is offline xrk971  United States
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Prezden,
Did you feel that there was a missing frequency patch or did it pretty much sound whole? 22 in should get you down to about 60 Hz I think. I think you must have more Cornu builds than anyone here. How many so far ?
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Old 20th September 2013, 05:35 PM   #1007
Dave R is offline Dave R  United States
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I noticed that the path length down one side of the split is different from the other side, maybe about 15%. How does this affect the output, in comparison to a single path (no split) with the same overall cross-section area?

This is my first horn encounter, just trying to understand how this stuff works.
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Old 20th September 2013, 05:48 PM   #1008
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Not sure but it's not that difficult to have made them all the same so Daniel must have discovered an advantage in doing it that way.
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Old 20th September 2013, 07:03 PM   #1009
xrk971 is offline xrk971  United States
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Quote:
Originally Posted by Dave R View Post
I noticed that the path length down one side of the split is different from the other side, maybe about 15%. How does this affect the output, in comparison to a single path (no split) with the same overall cross-section area?

This is my first horn encounter, just trying to understand how this stuff works.
It helps to provide a smoother frequency response. Look at the results of the simulation from the earlier post:

Click the image to open in full size.

The red (shorter path exits to the left on the bottom) and green (longer path exits down on the right) line represent the output from the two different length horns (just 2 of 4). If you had just one length, it would be double the amplitude of the green without the red to balance it.

Of course, this can be taken to an extreme as in the case of my Panpipe BLH (5 unequal length horns): The PANPIPE (Pentahorn) BLH Speaker

Click the image to open in full size.

Click the image to open in full size.

So far, no one has been crazy enough to make this to see if my simulations pan out

Last edited by xrk971; 20th September 2013 at 07:07 PM.
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Old 20th September 2013, 07:40 PM   #1010
prezden is offline prezden  Canada
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Hi X
When my friend and I were listening we both felt that they were possibly the best speakers we have heard. Now neither one of us is what I would call an audiofile but we have both listened to a lot of music for a long time. They are just really good sounding speakers
Thanks to you, Cal and others for making it possible to build them. These are the 4th pair I have made; all in different sizes and I think they all sound great.
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