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Discussion Starter #1
I'm looking for overhead Atmos speakers for my dedicated home theater room. It is 10 x 20 with an 8 foot ceiling. I am running all DefTech speakers currently- 3 Procenter 1000's for the LCR, 2 Mythos Gems for side surrounds, 2 8040BP for back surrounds and my current ceiling speakers are 4 Promonitor 800's. They are driven by a Denon X7200W Receiver and a Kenwood 895 Amp for the back ceiling channels.

I am looking for wide dispersion speakers for the Atmos ceilings, since that is what they recommend, although I have to admit the 800's do a really good job.

I was intrigued by the Vifa 4" 2 Way Coaxial 3.75" Driver & .75" Tweeter A10CC-07 that used to go into the M&K M-6 speakers. Vifa is a good name in driver design and I thought these might give me point source for the sound and also have wide dispersion due to the coaxial design. Am I correct in that assumption? I can't seem to find much information on the old M6 speakers from which I might gather further information.
 

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I've looked at the Volt line and they look good. It just I can pick up the Vifa coaxials for like $15-$25 each because M&K went out of business. I just wanted to make sure they would have wide dispersion. It's very hard to get any information about the old M&K M-6's they were designed for.
 

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I've looked at the Volt line and they look good. It just I can pick up the Vifa coaxials for like $15-$25 each because M&K went out of business. I just wanted to make sure they would have wide dispersion. It's very hard to get any information about the old M&K M-6's they were designed for.
By the way I was in no way slighting the Volts, they look like excellent speakers with excellent drivers. My problem is that the projector is pretty near the ceiling and I'm not sure the volts would be compact enough to fit in the area between the projector throw and the ceiling.

If someone could answer my initial question about coaxials having wide dispersion, I would appreciate it.

Thanks!
 

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I don't think coaxials have inherently wide dispersion. It's that their dispersion is even in all axes. Some coaxials have the woofer acting as a waveguide for the tweeter. Others have a horn for the tweeter behind or in front of the woofer.

Your 4" driver doesn't sound large enough to extend to subwoofer crossover and be efficient enough for theater applications.

That's one attraction to the 8 and 10" coaxials.
 

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Your 4" driver doesn't sound large enough to extend to subwoofer crossover and be efficient enough for theater applications.
And/or have high enough sensitivity for reference theater volume levels, though I'm not quite sure what Atmos speakers require offhand.
 

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Looks like the Vifa would require you to add a crossover. That would play a part in dispersion (where you cross over from woofer to tweeter). And then also the tweeter's waveguide. Do you know its pattern?

Having radial symmetry in overhead Atmos is helpful because audience is arrayed on axis, below and in front and to right and upper left of axis, etc. So you want consistent sound in all directions.
 

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I've attached a pic of the driver, and also a suggested schematic for a crossover. I discussed this yesterday with Ken Kreisel, and he said that he had designed a different crossover but did not have it handy. He's a terrific audio professional who will gladly answer questions.

There are two "fins" on the side of the tweeter in the coaxial. I assume these perform some kind of waveguide function, though they do not protrude beyond the tweeter. Perhaps they are there to increase the sweet spot?
 

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Yeah, that shape is when you want one pattern for horizontal and another for vertical. Usually limited vertical and wider horizontal.

I suppose used as a top speaker, that could work over one row of audience, oriented so widest pattern fires across the entire row and keeping sound off the front wall.

But if you have two rows, I'd think one with radial symmetry would work better.
 

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Yeah, that shape is when you want one pattern for horizontal and another for vertical. Usually limited vertical and wider horizontal.

I suppose used as a top speaker, that could work over one row of audience, oriented so widest pattern fires across the entire row and keeping sound off the front wall.

But if you have two rows, I'd think one with radial symmetry would work better.
Yeah, unfortunately, its sounding more and more like it's not the driver I need for my situation. Thanks for everyone's help!
 
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