Interesting Pro idea based on 6ND430

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I have been looking at the 18sound 6ND430 midrange driver. this looks like an interesting mid driver that has gotten some good reviews.
this has a high power handling, high acoustic output. and the 45 degree off axis response is actually flatter then the on axis response. plus this comes in 16, 8 and 4 ohm versions.

So my thoughts were to base a design around this driver for Small club PA use.

I havent settled on any one configuration yet and have been wondering about several different configs.

I woould want to use this with a 12" or maybe a 15" woofer and while this does have an impressive acoustic output, i might have to use 2 or more of them together. maybe in a MTM arraignment with a horn/driver chosen to compliment.

What would the disadvantages of a Single box with sub per side WMTMW arraignment be for live sound use?

Here is a quick concept idea i was thinking of. I thought about using 4 of the 18sound mid drivers at 45 degree angles with a center mounted horn. fiberglass would be used around the back of the horn to dampen the sound aimed at and reflected back from the mids. The idea being to use the 45 degree off axis response. front firing 12" woofers would be used to get the response down to at least 50hz before hitting -3db.

I can see many drawbacks to such a design. but it is an interesting concept. the drawing is not to any such scale other then the drivers/horn is to scale to one another.

One of the interesting things about a design like this is that depending on what horn/driver & woofer are used. all of the drivers voice coils could be nearly in a perfect line vertically without having to use a stepped cabinet.

The cavity that mids form hopefully will be large enough so that its resonance is well below the mids operating range. it could also be designed so that the sides in that are are open and that the horn is supported in the center or maybe with thin rails from the woofer areas or something.

I am curious what everyones thoughts would be about such a design. remember this is just a design concept for discussion.

An externally hosted image should be here but it was not working when we last tested it.
 
Already invented by VDOSC l-acoustic and JBL VERTEC.

j
 

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Yes but those lay horizontally. I am looking to use this vertically as drawn. and not as an array element.

Line array elements have a very narrow vertical pattern but wide horizontally. typically 10-15 degrees Vert.

I am looking for something not so narrow, or wide. 60x40 maybe, not not less then 40x20


Think of these as high output very large room audiophile speakers.
 
Zero Cool said:

Think of these as high output very large room audiophile speakers.

Hi,

In that case you should be looking at a WMT or WMTMW.
And designing them like a hi-fi speaker.

Trying to use the 45 degree response is not a good idea.
Controlling the on axis response via the crossover is easy.

So do it with something like :
http://www.rjbaudio.com/Audiofiles/FRDtools.html

Though as pro speakers I would not bother with losing
efficiency due to baffle step, the can be easily EQ'd.

And check excursion / power handling limits in WinISDpro.

:)/sreten.
 
Ok what if i were to put a single 15, two of the 6ND430 mids and then a horn on top? a more conventional approach.

Should the mids be side by side as close together as possible? or would a MTM arraingment be better?

I dont really want to use two mids but i am afraid one wont be enough to keep up with the horn and 15" these things do have some seriously impressive output however.


Zc
 
Here's another option for the mids, using the 18Sound 6NMB420. I thought the enlosure was large enough to allow a horn loaded mid running ~300Hz up to 2-3KHz.

McBean says we get this response from loading a single 6NMB420 in a 35cm long conical horn, 36cm2 throat, 1000cm2 mouth.

Typically you see more HF extension than McBean predicts. Bill Fitzmaurice has some nice info on his site regarding this

-Len.
 

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And the input parameters

I used a rear volume of 1.7 litres (I look to reduce the electrical impedance peak by playing around with this volume) - as far as I'm aware this is nulling out the reactive component of the driver. I'm sure more knowledgable readers will correct me on this :)

Front volume is 120cm3 to flatten the passband response at the expense of a little HF extension. Looks good to 2K+, should be better in real life.

-Len.
 

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