horn top splaying |
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madboffin
Old Croc Joined: 03 July 2009 Location: Milton Keynes Status: Offline Points: 1537 |
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Theory is all very well, but that's assuming a perfect horn with absolutely consistent coverage at all frequencies and perfect combination between units.
I don't think anyone has achieved this yet, despite almost 100 years of trying. Some have come quite close, so I wish you luck. You can expect typical 50 or 60 degree horns to give smoothest combination with a splay angle of about 40 degrees. Your first illustration used to be known as a "barber's pole array" and was a favoured way to stack the horns in old-fashioned rigs, but it involved an overlap rather than aligning the horn walls. |
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fourway hornloaded
Registered User Joined: 16 March 2014 Location: Hamburg Status: Offline Points: 60 |
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so madboffin, from what you're saying:
When trying to figure out a 3-a-side horn top (splay angle ~ 40 degrees) I could just use 60 degree high frequency horns? They're a lot easier to find than 40 degree horns. Most manufacturers don't even list 40 degree horns, only 90 and 60. thx robert |
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haystacK
Registered User Joined: 12 March 2010 Location: California Status: Offline Points: 35 |
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Adding on here with a question about the angle of these mids. They are splayed horizontally to keep a stack lower, they would be side by side. Do you see any issues with the 45 degree dispersion with the panel split between drivers? No logic or reasoning behind the curved design other than aesthetics and hopefully not an issue with overlap to soon/close. If 12" drivers are not arrayed, is the only reason for them to be vertical for coupling because of the dispersion angle of the cabinet? I understand coupling (somewhat) but is this a reason why double mids are not typically designed in a horizontal array?
thnx guyz
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_Natty_
Young Croc Joined: 01 April 2007 Status: Offline Points: 663 |
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it looks like exactly what i've in my mind for my 12"...I need too to keep the stack lower! is it your plan or just a design scratch? cheers
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corell
Young Croc Joined: 19 August 2013 Location: Berlin Status: Offline Points: 1161 |
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It is generally not a problem to array 12" mids horizontal, allmost every big size Line Array does so.
There are a few things to consider though: Is the distance between the 12" small enough for them to couple completely (below your intended x over frequency)? If so, the dispersion will get narrower in the horizontal plane, not wider! Is this desired? If not, what dispersion angle does one single 12" has at its upper x over frequency and what angle between the two arrayed chassis should be chosen then? The dispersion will get narrower in the lower passband and wider in the upper one where they start acting as individual sources (depending on the splay angle). This is contrary to the narrowing behaviour of a point source to higher frequencies and will then give you a more constant directivity if done right. Try answering these questions yourself first. It will help you understand what can be done and what cant. We will help then. You should however avoid parallel walls in front of the 12" by any chance! there will be nasty resonances otherwise. Also, you will get some sort of bandpass effect in that "frontchamber" which will limit your upper corner frequency. |
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Teunos
Old Croc Joined: 23 November 2008 Location: The Netherlands Status: Offline Points: 1799 |
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This piece of information right here, is something nearly 99% of people overlook when arraying tops even though its pretty basis physics. Coming back on Andywave's post, Here is a chart i pulled from one of the Peavey papers on different horn geometries. Notice the narrowing in directivity behavior between 1kHz-2.5kHz?
Edited by Teunos - 25 November 2016 at 6:01pm |
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Best regards,
Teun. |
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tv00
Old Croc Joined: 10 August 2009 Location: Denmark Status: Offline Points: 1886 |
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Not often I see a horn where the driver sits in front and S1 part of the horn is bigger than SD and the whole driver itself, so would you say this horn has de-compression? :-) |
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Wrek0ne
Young Croc Joined: 10 February 2011 Location: Cambridge Status: Offline Points: 749 |
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With no compression at the throat it wouldn't necessarily be considered a horn at all, more of a wave guide perhaps? |
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Poll this!
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haystacK
Registered User Joined: 12 March 2010 Location: California Status: Offline Points: 35 |
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Hey Natty, the design is just a horizontal SMT that I drew. Thanks for the reply Corel, they would sit on top of ES18’s crossed around 200Hz. The center panel essentially splits what would be (2) cabinets so the distance between the drivers is 18mm less than if two were side by side. Their combined angle is based on half the dispersion, 22.5 degrees off axis if perpendicular to the face. If it is direct radiating but splayed like this there is no need for sectioning between the drivers like this correct? Even more, a flared design with horizontal expansion on the side panels does not make sense with this layout because it is an arrayed cabinet correct? Insert face palm emoji. :D
Thanks for the inputs, I know this has been discussed but just trying to get my head wrapped around it. |
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_Natty_
Young Croc Joined: 01 April 2007 Status: Offline Points: 663 |
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smt but with no reflex i guess...
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Engineer
Registered User Joined: 04 May 2011 Status: Offline Points: 34 |
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mmm...phillishaves ?
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