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Old 2nd January 2010, 09:04 PM   #11
deiksac is offline deiksac  Czech Republic
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you did not mention where do you want to use it. be it PA, your ciare probably wont last very long. Pushing an 18" in a closed horn requires quite a robust driver, something like Precision Devices 186 or better ...
Be it home cinema you should be okay
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Old 2nd January 2010, 09:12 PM   #12
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i will be using it outdoor
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Old 2nd January 2010, 09:14 PM   #13
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10s are stronger than 18s. The bigger the cone, the more fragile it is. I can't for sure if the 3.6:1 compression ratio of my quickly made tapped horn will tear the cone of the 18.00 SW driver you want to use.
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Old 2nd January 2010, 09:21 PM   #14
deiksac is offline deiksac  Czech Republic
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well you should also consider portability, beasts as big as those will require some hands to carry them around :-)
what is the rest of the soundsystem supposed to be? these ciares arent very sensitive and with an Fs od 36 Hz I doubt they would produce significant output below that anyway ...
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Old 2nd January 2010, 09:27 PM   #15
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Originally Posted by soundhead View Post
i will be using it outdoor
Trying to generate 20hz outside is a great way to blow up a speaker I'm afraid. Even the labhorns were limited to about 30hz, and that was a VERY sophisticated design.

I'm not saying it can't be done, but it requires a LOT of excursion.

Remember, a horn behaves like a sealed box *below* it's cutoff. So pouring power into the horn to get it to play 20hz makes the driver go *pop*

If I were going to generate 20hz outdoors I would personally use a huge array of sealed or vented boxes. And when I mean huge, I mean a minimum of eight fifteens, and thirty two would be even better.

P Audio 15-inch subwoofer speakers and replacement subwoofers
The SN15B is nice, and it's on sale for $99

I've built a LOT of horns and tapped horns, and I don't even bother trying to get real output below 30hz. I know that it's nice to have a sub that gets down to 15-20hz, but the size of the sub gets goofy when it's any kind of a horn.

If you want to have your cake and eat it too, you might consider both. Use an array of sealed boxes for infrabass, and bass horns for 30-120hz. High pass the horns so you don't fry your woofers, then run the sealed boxes at reduced volume to add some "weight" to the presentation.

At very low frequencies it's easy to mix front loaded horns and sealed boxes, because front loaded horns BEHAVE like sealed boxes at very low frequencies.

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Old 2nd January 2010, 09:30 PM   #16
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This is the progression chart of my tapped horn. It assumes a 30" (29" internal) width. Use it to make a cut-out with graph paper and try making a fold for it.

Do you first cab in cheap 1/2" ply with plenty of bracing. Use a string for measuring path length to finalize your dimensions. Use screws through-out, but no glue. Use plumbers paste for fill so it can be taken apart should you want to modify the dimensions.
Attached Files
File Type: txt cair180s.txt (17.7 KB, 95 views)
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Old 2nd January 2010, 10:01 PM   #17
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Originally Posted by Patrick Bateman View Post
I'm not saying it can't be done, but it requires a LOT of excursion.
Either excursion or loading from a very long and large cabinet. And hopefully with FLH he uses many boxes to get the mouth area up. I'm still assuming 1/2 space with no boundary effect.

Yup, kinda crazy, but about the only way, I feel, to explain this to him, is to follow what he requests to show him how impossible it is.
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Old 2nd January 2010, 10:23 PM   #18
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Richard Long had a great 2 x 18 inch hyperbolic expansion folded bass horn called the Levan after Leroy Levan with influence from the early RCA theatre horn. The W bass box without the mouth expansion was called Bertha (the EAW BH 882 is fairly similar and they made some of Richard's cabinets including the bass horns at times). The drivers were custom made Emience's if I recall correctly (attempts to substitute " better " JBL , Celestion, etc drivers with incorrect driver parameters resulted in short driver life span - hours. The mouth of the standard 2 bend mouth version is 8 ft x 42 inches and I had 4 of the even larger 10 ft x 42 inch triple bend mouth versions double stacked for a 10 ft x 7 ft mouth - powered by crest 1800 watt mono blocks per side - band pass filtered at 20 and 100 hz. - as mentioned by Dave above you don 't want to drive a horn below it's bandpass nor above it's hf limit for a bass horn especially a hyperbolic - fastest expansion to a low cutoff F but also the quickest to generate hf distortion if you go too high. Not exactly portable unless you make the mouth seperatly and in 2 halfs that could bolt together on site

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Old 3rd January 2010, 12:48 AM   #19
godfrey is offline godfrey  South Africa
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Hi soundhead

That horn (in post 7) is a good match for the Ciare sw 18.
Response / efficiency should be excellent down to 30 hz, but dropping fast below that. (i.e. forget about 20hz) Do you really need to get to 20hz, though? What's it going to be used for? I think you mentioned using a bank of four outdoors?

btw: The back chamber wants to be about 2 cubic feet for this, which should actually make the woodwork easier - as far as I can make out, the plan calls for wasting some space, which may as well be put to good use.

I tried looking it up on tda-audio - PhotoFile.name / id: usr to get more details, but got lost - everything's in russian. Have you got a link to the page where you found this?

Cheers - Godfrey

edit: oops - missed a whole page of posts while I was simming and typing

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Old 3rd January 2010, 01:10 AM   #20
godfrey is offline godfrey  South Africa
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The 12P basshorn looks good too - similar to a labhorn but with better cooling. Gets down to about 35 hz.
Pi Speakers - unmatched quality and state-of-the-art performance

Also - lots of practical stuff here:
Graeme's DIY pages
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