Bladesmiths' Open Baffle Project.....

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bladesmith

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Re: Bladesmiths' Open Baffle Project.....
« Reply #20 on: 29 May 2015, 06:45 pm »
So you're crossing over from a G1 ribbon to a 10" woofer?  Have you taken any measurements to see how that Morel performs?  My guess is it's going to very bumpy FR from 800-2500hz, and that you'd be better off with something smaller to cover that range.  It's directivity is also going to narrow significantly toward the upper end of that range. 

Where did the schematic for the crossovers you say you completed come from? 

My suggestion would be to take a step back before progressing further, re-evaluate the design on paper and likely make some adjustments.  My first thought would be attempt something like a 3.5way, where both the Morel and Eminence have no high pass filter on them, but different low pass points.  And with that use a high sensitivity midrange (of smaller diameter than the Morel).  That would be a somewhat complex design however, and you would need to take measurements if you're to have any chance of success.

Ryan,

I built the x-overs, I do have some experience in the Technical world of electronics. I spent the first eight years of my working life as an Electronics Tech for the Military, 4 years in the Air Force then another four years working as a contractor for the DoD. It's not as hard as you think, making x-overs. Or as hard as YOU make it out to be. When you break it down into a simple low-pass filter and a simple high-pass filter. It's not rocket science.

V...

bladesmith

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Re: Bladesmiths' Open Baffle Project.....
« Reply #21 on: 29 May 2015, 06:56 pm »
Welcome to speaker design, no shortage of considerations  :)  Here are my thoughts

The 10" Morel being an older design, and knowing similar drivers, likely has no copper in the motor.  That means midrange distortion will climb, and likely be significantly higher than a more modern design with copper shorting rings.  And while the frequency response might measure somewhat flat up to 2500hz, I guarantee the cone is not retaining pistonic motion above 1000hz.  Typically the first spot you see a blip on the FR is where pistonic motion stops, my best guess is 800hz.  Above that point it can still sound good, but you are losing resolution/transparency when the cone starts flapping like a flag in the breeze.  Other issues, inductance is rising pretty steeply through the upper midrange with that driver, and 3" VC drivers just aren't as good with midrange. 

Those things aren't to say it can't sound good, but just be aware of what you're giving up. 

Yes absolutely directivity will narrow significantly from 1000-2500hz too.  Being a soft cone, you might get 1-200hz more out of it before it starts to narrow, but that's based on cone diameter primarily.  So there's nothing that's going to be able to negate that issue.  People do make too much out of things like Polar Plots IMO though, the first impulse (on axis response) is far more important.  Power response is an important consideration of course, but at least if you get a respectable on axis response and put them in a room that isn't too reflective, you can get away with a poor power response.  Being OB will contribute and fill in the power response in some areas too, but how exactly I couldn't say without data. 

To sum it up, go ahead and build and enjoy as is ... but be open to the idea of adding a smaller midrange driver to bridge that gap between the ribbon and 10" woofer down the road.

Ryan,

I got some of my ideas about open baffle speakers from wwwpureaudioproject.com . Of course I didn't just make a copy of there speakers, but they have some good ideas, IMHO. I added a much better tweeter than they use and a better 15" woofer than they use, again, IMHO. My speakers are also about 90 pounds each, which help. I think a lot of OB speakers are made in a structure that is too little or not heavy enough, if you know what I mean. I think the actual weight of the speaker structure helps with the overall sound.

My speakers sound great... simple and sweet and open. I'm not much of a box speaker listener anymore. I just, personally like OB speakers better.

Thanks for all of your input, it was graciously considered.

V....

mlundy57

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Re: Bladesmiths' Open Baffle Project.....
« Reply #22 on: 5 Jun 2015, 04:23 am »
Not great pics, but, I haven't been able to do much lately. I need a nice sunny day to get better pics but, you get the idea...I finished these some time ago, just not the time to do the things I want right now.

The Rosewood came out very nicely. And they sound very sweet. I have a variable resister on the tweeter output, so I can dial them in. Same goes with the separate amp I use for the 15" bass driver. So everything is very flexible. Both outputs of my amps are also adjustable.




Those look really sharp. Love the rosewood.

Mike










bladesmith

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Re: Bladesmiths' Open Baffle Project.....
« Reply #23 on: 6 Jun 2015, 06:20 pm »
I built my x-overs using a high density plastic, with spacers. And ran the wires on the underside.











« Last Edit: 29 Jul 2015, 12:38 am by bladesmith »