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Author Topic: Hornresp 80Hz Candidate  (Read 8342 times)

Antone Atmarama Bajor

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Hornresp 80Hz Candidate
« on: May 27, 2006, 02:51:40 pm »

     Ok I have come up with a 80Hz Horn Design Candidate, I would like to get some feedback and ask some questions.

    A question arose when looking at the Lab v3 Vs Lab "v2".

    What are the implications of having a Hyperbolic Sine Horn (expansion rate greater than 1).  That apears to be how the Lab v3 was built.

    I am asuming that the LAB subs where designed with a Size Factor of 4?

    How flexible are the mouth dimensions for a size factor 2 Horn?

    Would optimal be either a circle of appropriate radius/ square that is the sqr(area).  I'm wondering this since the Labs only have an expansion on one axis.  

    Could a rectangular mouth that expands on one axis (and meets all of the area requirments be as usefull in a size factor of 2 horn?

    When I exported the data from the horn flare, it gave me grayed out symetrical dimensions.  If I just keep the height constant what can I expect good performance If I just accept the single axis expansion (say if I stack them 2 High?)

    Any how here is one of the horns I am modeling.

Its a segmented aproximation of a Hyperbolic expansion rate of .55.

    Using exponential or conical sections in the model don't seem to make much difference.

index.php/fa/4907/0/

Antone-
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Antone Atmarama Bajor

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Re: Hornresp 80Hz Candidate
« Reply #1 on: May 27, 2006, 02:53:43 pm »

Here is predicted response of 2 half space with 1 in gray.

index.php/fa/4908/0/
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Antone Atmarama Bajor

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Re: Hornresp 80Hz Candidate
« Reply #2 on: May 27, 2006, 03:41:45 pm »

Ohh PS the drivers are JBL 2225's
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peter.golde

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Re: Hornresp 80Hz Candidate
« Reply #3 on: May 27, 2006, 04:09:20 pm »

Why 1/2 space? Will these be sitting on the ground?
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Jeff Robinson

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Re: Hornresp 80Hz Candidate
« Reply #4 on: May 28, 2006, 02:31:51 am »

Hi Antone

I've been shooting for 100Hz with less than 1 meter of throat length.

So far this is the best I've modelled in Hornresp.
4 Pi space load but note the T/S parameters are for dual EVM10M driver source.

Please excuse the cobbled together graphics.

index.php/fa/4910/0/

I think for ground stacked subs 1/2 space is right,
but for midbass in mobile PA you ought to allow for use of singles in free air.

I think Dwg86 models ok for 3 or 2/cluster and even 1 doesn't look bad considering the 1 meter throat length constraint.

The problem will be the tight spacing from the phase plug to the boundary wall.

My thanks to Bill Geiger for suggesting the dual driver format as a means of shortening the horn.

Jeff Robinson

PS; The most compact graphics file format I've found is png, I'll see your 200KB and raise you 16KB.
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Antone Atmarama Bajor

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Re: Hornresp 80Hz Candidate
« Reply #5 on: May 28, 2006, 04:51:43 am »

Sometimes they will be on the Ground yes.

    The rest of the time they will be on top of BT7's.

I have yet to find anything that models well in Free space unless I want to build a horn of Size Factor 1.

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Antone Atmarama Bajor

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Part 2
« Reply #6 on: May 28, 2006, 03:05:13 pm »

     Ok I tried Changing the Chamber Volume a bit since that seemed to effect my performance a bit.

    This should perform in free space like 1 in half-space.

Yet another hyperbolic approximation 122 cm long flare .55 80Hz.



index.php/fa/4919/0/

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Antone Atmarama Bajor

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Re: Part 2
« Reply #7 on: May 28, 2006, 03:12:41 pm »

Here are the numbers.

Question:

    If you have to consider cone volume when solving for Throat chamber.  Why does Hornresp try to override it when you are trying to use its hypex calculator?

    Wouldn't that mean you have to stick a mass between the cone and throat to take up the cone area?

index.php/fa/4920/0/

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Bogdan Popescu

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Re: Hornresp 80Hz Candidate
« Reply #8 on: May 30, 2006, 02:47:07 am »

Isn't this DDS horn not the perfect candidate ?
I am considering it for my midbas.

http://www.ddshorns.com/catalog.php?page=DVB15NPro

Bogdan
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Antone Atmarama Bajor

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Re: Hornresp 80Hz Candidate
« Reply #9 on: May 30, 2006, 04:50:19 am »

     I seriously doubt the DDS horn has much effective loading down bellow 200Hz with those dimensions.  It will probably behave just like normal direct radiator in a sealed or vented enclosure below horn flare and length.

   I would think this would work only for Low Mid not Mid Bass.  You can't cheat physics.

Antone
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