NX-Otica MTM - rectangle base

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Optimizer

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Re: NX-Otica MTM - rectangle base
« Reply #20 on: 6 Feb 2021, 08:54 pm »
On the next picture below you can see that I did not changed trapezoid configuration. Both wings are opened cca 10 degrees out. Hence it should be OK.



Tyson

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Re: NX-Otica MTM - rectangle base
« Reply #21 on: 6 Feb 2021, 09:08 pm »
It's very clever :thumb:

mlundy57

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Re: NX-Otica MTM - rectangle base
« Reply #22 on: 6 Feb 2021, 09:29 pm »
Not sure how strudy the short wing would be beveled like that nor how the pointed edge would behave. You’d have to mock up a speaker and send it to Danny for testing like I did with the prototype I posted pics of

Early B.

Re: NX-Otica MTM - rectangle base
« Reply #23 on: 6 Feb 2021, 09:51 pm »
Not sure how strudy the short wing would be beveled like that nor how the pointed edge would behave. You’d have to mock up a speaker and send it to Danny for testing like I did with the prototype I posted pics of

Yeah, even a very slight modification requires going back to the bench.

Besides, there's no real world benefit to rectangulate the base. Sure, you shave off a couple of square inches, but that's insignificant. This speaker is huge in real life. It's still gonna be at least 14" deep and angled no matter what you do.

Expand your options. Consider a metal base. This can be improved upon, but it's thinner and sturdier than MDF, looks badass, and allows for all sorts of footers.
 

 

Jonathon Janusz

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Re: NX-Otica MTM - rectangle base
« Reply #24 on: 6 Feb 2021, 10:54 pm »
On the next picture below you can see that I did not changed trapezoid configuration. Both wings are opened cca 10 degrees out. Hence it should be OK.



I'll try one more time before bowing out.  See the lines on the short wing (right) side of this picture that outline the space missing from the original wing (the white lines marking the black void space beside the angled cut/modeled wing)?  The outermost line - which would be the outside face of the wing in the reference designed cabinet - is the critical part.  By removing it, you have changed the angle of the outside face of the short wing and folded it behind the front baffle instead of having it extend away from the front baffle by ten degrees. 

I know to get what you're after you want that angle gone, but it is a (the most) critical part of the wing design.  Sure, your wing makes the baffle's effective width the same as if the angle was ten degrees out as per the reference design (the clever part) but the angle is wrong - ten degrees the wrong way.  I'm sure if the speaker could have been optimally designed with squared off wings to produce the response Danny was after, he would have just left them squared off (because it would make cabinet assembly and manufacture much easier), but bottom line is that everything matters, how the sound wraps around the cabinet matters, and it may be small but your design will change that.  I'm not saying it won't work; it just won't end up as intended.

Not sure how strudy the short wing would be beveled like that nor how the pointed edge would behave. You’d have to mock up a speaker and send it to Danny for testing like I did with the prototype I posted pics of

This is really the best answer, and the only way to make sure you end up with a final product that meets the performance of the design as-is.  If Danny hasn't tried it out already to know whether it would be fine or not (or what if any crossover changes are needed or not to make it work), I'm sure he'd be glad to measure a test cabinet you build out and send him to check it out.  We're all here just trying to help out to make sure you get a great sounding speaker and end up with a speaker you'll like.  :thumb:

Good luck!

jn316

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Re: NX-Otica MTM - rectangle base
« Reply #25 on: 6 Feb 2021, 11:07 pm »
It's the OUTSIDE of the wing that makes the difference? I would have assumed it was only the inside, but that does make some sense if you think about the separation of the front wave and the back wave.
If true, just keep the short wing thickness throughout and square up the base to the outside edge of it....don't square up to the front of the baffle but to the back of the wing. That only makes the base slightly wider, but you have the full short wing then.

Jonathon Janusz

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Re: NX-Otica MTM - rectangle base
« Reply #26 on: 7 Feb 2021, 01:49 am »
Thank you!!! I thought I was  :banghead: failing at explaining it!

From what Danny has shown (search prior threads where folks discuss the wings on OB speakers) here, both sides matter, but in different ways.  Check out the design thread for the NX-Otica to see how the design process evolved to the shape the final cabinet was made, which similarly will apply to this MTM version.  It doesn't seem like such a small angle should matter much for such a small wing on such a small baffle, but as has been said many times before, everything matters.

Optimizer

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Re: NX-Otica MTM - rectangle base
« Reply #27 on: 7 Feb 2021, 07:59 am »
Danny mentioned size of the wings, not their thickness. But you are right. Some wave lengths may be affected - cancelled.
But which and how much? Can't say. I don't know. But I am pretty sure that with some modification of the short wing it will work.
The only way to reveal potential issues is to do some measurements.
« Last Edit: 7 Feb 2021, 10:35 am by Optimizer »

Jonathon Janusz

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Re: NX-Otica MTM - rectangle base
« Reply #28 on: 7 Feb 2021, 02:48 pm »
Danny mentioned size of the wings, not their thickness. But you are right. Some wave lengths may be affected - cancelled.
But which and how much? Can't say. I don't know. But I am pretty sure that with some modification of the short wing it will work.
The only way to reveal potential issues is to do some measurements.

It isn't the thickness of the wing that's the concern; it is the geometry.  As long as you end up with the same outside dimensions and geometry of the reference design while maintaining enough rigidity/structural strength that the box doesn't fall or rattle apart, you'd still be good to go.

Take the X-Otica design for example (very similar to this one but using a dome tweeter instead of the neo-3, just to ignore the needed depth for the tweeter wave guide for sake of example).  You could bend a sheet of, say, 1/8" plate steel or aluminum and end up with a working baffle so long as you bent it in the same trapezoidal shape with the same outside dimensions (maintaining the geometry, reducing the thickness).

It isn't a matter of revealing potential issues at this point, that there will be issues is a given; a test cabinet and measurements will determine what Danny has to do to the crossover to get as close to the reference design as possible and what if any performance compromises are made in the end result regardless of what has to change.  Check out this thread where Danny discusses baffles and follow the link he posts to the thread discussing the Wedgie.  I think it very clearly shows what you're up against here:

https://www.audiocircle.com/index.php?topic=160242.0

Optimizer

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Re: NX-Otica MTM - rectangle base
« Reply #29 on: 8 Feb 2021, 06:10 pm »
Everything matters but some things goes beyond my imagination. Short wing is there to avoid cavity resonance. It is also importat to separate the front wave from the back wave. All aspects Danny mentioned. He developed design that works well.
I don't want change anything about that. My only intention was to change base shape and that's it. If someone do some measurements and say that there is a big problem with this design I will accept it easely. Now I don't see unsolvable problem here.

Captainhemo

Re: NX-Otica MTM - rectangle base
« Reply #30 on: 8 Feb 2021, 07:14 pm »
I posted this a long times ago in another thread ....  from  ouir original design of these:



.You  can make the base square if you  want ( just transfer the dowel/screw pattern from orignal base  to a rectangle base) or,  cut as Mike  suggested.
In either case, you   won't  get the   wedged wings parallel with  a square/rectanular  base... if you did, it wouldn't be a wedge  anymore  :)


jay

hogwild

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Re: NX-Otica MTM - rectangle base
« Reply #31 on: 24 Apr 2024, 10:07 pm »
Sorry to necro an old thread, but... do I remember correctly that the long side baffle is 20" deep and the other was about 4"?

Hobbsmeerkat

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Re: NX-Otica MTM - rectangle base
« Reply #32 on: 24 Apr 2024, 10:58 pm »
Sorry to necro an old thread, but... do I remember correctly that the long side baffle is 20" deep and the other was about 4"?
The long side is 14 inches long (past the back face of the baffle) while the short side varies.
Around the mids, they are 2" long at the mids and flush at the tweeter. for the Otica/Xtreme they are 14" deep at the bass drivers.