Ever think of building a Cornu Spiral horn? Now you can!

Coen · 2014-05-11 10:56 pm

tfcx said:
Also(for next time), you might try putting a piece of masking tape on the screwdriver tip prior to driving the screws.

And i actually did that. Well i used a piece of cloth, but the screw holes where on the small side so i needed to use some force which caused the paint to come off anyway. But i'm very happy the way they look now

xrk971 said:
Looks great Coen! Tip: use a black Sharpie permanent marker to touch up the paint.

That's a good idea, i'll go get one.

X, if it's not to much trouble.. could i bother you for 2 sims? I decided on building my third (and probably final) pair and Cal convinced me, they're going to be big.

A while back you did a sim for me of the Fostex FE166En in a 40inch cornu, which looked really good. But i was hoping to get away with 36inch, could you do a sim of that? i'm guessing 5inch dept like Cal has for his 36" cornus. And the other option i was looking at was the Mark Audio Alpair 10.3.

Alpair 10 Gen.3

T/S date LMS V4 Anechoic:

Revc= 7.200 Ohm

Fo= 38.266 Hz

Sd= 8.825K mm2

Vas= 26.320 Ltr

Cms= 2.380m M/N

Mmd= 6.792 g

Mms= 7.269 g

BL= 5.772 TM

Qms= 1.930

Qes= 0.378

Qts= 0.316

Levc= 71.379u H

No= 0.378 %

SPLo= 87.988 dB

Xmax = 7.5mm (1 way with Arrestor)

Power = 30 watts nom.

I hope it's not to much trouble

j.michael droke · 2014-05-11 11:44 pm

big FC: question and link

Cal Weldon said:
For anyone interested, I have to say that I will not build the smaller ones anymore. Once you build the larger units, you'll see why. The differences between the 20", 27" and 36" are staggering. So much so that I don't even bring the little ones out anymore.

Hi there Cal: Q: Are the big Fc's just longer spirals or they both longer and thicker? Which driver was used? Is there a link to your construction? ...regards, Michael

prezden · 2014-05-12 1:02 am

I've used black artist acrylic with a small brush after the screws are in place. Works really well.

Cal Weldon · 2014-05-12 2:31 am

j.michael droke said:
Is there a link to your construction?

Hi Michael, it's the same as the others but here's where this one got going.

http://www.diyaudio.com/forums/full...u-spiral-horn-now-you-can-40.html#post3896058

j.michael droke · 2014-05-12 5:13 am

Cal's FC construction

Hi there Cal: Thanks for the link to the really big ones. ...regards, Michael

xrk971 · 2014-05-12 7:37 pm

Coen said:
And i actually did that. Well i used a piece of cloth, but the screw holes where on the small side so i needed to use some force which caused the paint to come off anyway. But i'm very happy the way they look now

That's a good idea, i'll go get one.

X, if it's not to much trouble.. could i bother you for 2 sims? I decided on building my third (and probably final) pair and Cal convinced me, they're going to be big.

A while back you did a sim for me of the Fostex FE166En in a 40inch cornu, which looked really good. But i was hoping to get away with 36inch, could you do a sim of that? i'm guessing 5inch dept like Cal has for his 36" cornus. And the other option i was looking at was the Mark Audio Alpair 10.3.

Alpair 10 Gen.3

T/S date LMS V4 Anechoic:

Revc= 7.200 Ohm

Fo= 38.266 Hz

Sd= 8.825K mm2

Vas= 26.320 Ltr

Cms= 2.380m M/N

Mmd= 6.792 g

Mms= 7.269 g

BL= 5.772 TM

Qms= 1.930

Qes= 0.378

Qts= 0.316

Levc= 71.379u H

No= 0.378 %

SPLo= 87.988 dB

Xmax = 7.5mm (1 way with Arrestor)
Power = 30 watts nom.

I hope it's not to much trouble

Here you go... looks like it will work well in 36 in x 5 in deep.

Coen · 2014-05-12 7:42 pm

xrk971 said:
Here you go... looks like it will work well in 36 in x 5 in deep.

Thank you so much! that's the fostex right? or the alpair?

if it's the fostex, i remember the 40 inch one

eek

looked better

> The FE166EN is a 6.5 in class driver and will not physically fit in the driver chamber unless you scaled up to a 40 in x 6 in deep Cornu. The Freq response looks very good and it will go all the way to high 40 Hz.

373121d1380140383-ever-think-building-cornu-spiral-horn-now-you-can-cornu-40x6-fe166en-freq-1m.png

xrk971 · 2014-05-12 9:10 pm

That was Alpair 10.3 in 36 inch Cornu.

Cal Weldon · 2014-05-12 9:10 pm

Just last night I had them on again and starting laughing. I couldn't believe the sound coming from those 35 year old 5.25" drivers.

xrk971 · 2014-05-12 9:11 pm

Cal Weldon said:
Just last night I had them on again and starting laughing. I couldn't believe the sound coming from those 35 year old 5.25" drivers.

Dude, puhleeez get us a mp3 or YouTube recording.

Coen · 2014-05-12 9:26 pm

xrk971 said:
That was Alpair 10.3 in 36 inch Cornu.

Ah gr8

dont suppose you still have that FE166 sim you did with the 40 inch and can see what it looks like in 36 inch?

xrk971 · 2014-05-12 10:32 pm

Coen said:
Ah gr8 dont suppose you still have that FE166 sim you did with the 40 inch and can see what it looks like in 36 inch?

I have a soft spot for orange tabbies...

Here is the FE166EN in a 36 in x 6 in Cornu. You may have a had time getting the basket and magnet to fit in the central driver chamber. Check scaled drawing and trim chamber if needed.

Cal Weldon · 2014-05-12 10:34 pm

This will be the song I'll record:

https://www.youtube.com/watch?v=tbNlMtqrYS0&feature=kp

Coen · 2014-05-12 11:58 pm

xrk971 said:
I have a soft spot for orange tabbies...

Here is the FE166EN in a 36 in x 6 in Cornu. You may have a had time getting the basket and magnet to fit in the central driver chamber. Check scaled drawing and trim chamber if needed.

Thanks you so much! you are the greatest :worship:

As far as the driver chaimber goes, if you build the horns all the way to the edge of the box the size is 17.1% (the mounting hole on the drawing was 14.3%) So it should fit with a few mm to spare on each side.

Something else i was wondering (its probably been discussed before) The original cornu has this splitter going trough the middle, so instead of 4 deep horns it has 8 shallow ones. Would it be a big difference if i made the splitter instead of doing it without? and what would actually be the difference. And has anyone experimented with different horn lengths? (perhaps have one side of the splitter the original horns and change them on the other side?)

Cal Weldon · 2014-05-13 5:55 pm

Well now because I didn't order the PLUS thingy, I have to 'wait in line' so it another 45 minutes until we can view the vid. Anyway, I have to go make some money so I can afford PLUS.

Here is the link.
https://vimeo.com/95167043

iko · 2014-05-13 6:32 pm

Awesome! Feels like big sound. Thanks for all the effort Cal!

xrk971 · 2014-05-13 6:34 pm

Cal,
You dah man! It sounds awesome and I think there will be a lot more Cornu builders after folks listen to this. :cheers:

Indeed, the 30 year old Radio Shack drivers in 36 in Cornu are very impressive. Great recording - the clarity, dynamics, and bass articulation, it's all there when you use good headphones to listen. It only took about 4 pages of posts before it all worked - but you got it. Yor HD cam did a great job with sound quality (and video quality). Now you have all of us giggling and giddy too.

Thank you!

X

Please post link to this vid in Post #1 as index...

Cal Weldon · 2014-05-13 9:09 pm

Wow,

I have finished my rounds and I am really happy to 'hear the results. So the mic is ok huh?

Thanks to X and perceval for the encouragement to keep me going and thanks to iko for that site

You guys are dah men!

X, that movie was shot on a Canon SX40 point and shoot still cam.

I am going to wipe out all those extra posts.

Coen · 2014-05-13 9:12 pm

Sounds great Cal, glad you managed to get it online somewhere!

Cal Weldon · 2014-05-13 9:25 pm

You were a big part of the inspiration to Coen.

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