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Get familiar with the reaction system: Introducing the Reaction System
Micro-Waves
I'm starting another project before completing the last...few, par for the course. Anyway, I'm looking to pair the 4" ceramic woofer from the Micro-C (SB12CACS25-8) with a Viawave RT850 in the PE 0.23ft^3 knockdown cabs. I'll call them the Micro-Waves. I plan having the baffles be removable to allow for future project ease of use. One thought I had was to mount the Viawave above the cabinet on a larger baffle than what came stock. This will help with port placement as the Viawave is rather deep. Here is CAD model of the proposed design. Looking for input, thanks in advance.
Comments
Might play with a squared off baffle vs. rounded to see which gives the fewest squiggles.
PE .23ft^3 cabs glued and baffle CNC'd from some cheap Aldi bamboo cutting boards.
Looks great! Those were some thick cutting boards.
Izat bamboo as hard to cut as it looks?
I've done something similar. I started with an MDF tower flatpack from PE. I wanted the tweeter higher up, more in-line with ear height so that is what I came up with. I hid the tweeter wiring in the baffle by drilling at an angle through the baffle into the interior of the enclosure. Then once the wires were in place I sealed it with silicone.
Looks similar to what I did with my Nephila using the tower flat pack.
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It looks like you already cut the baffle. I worry about the possibility of a strong diffraction signature impacting the tweeter. The edge of the baffle around the top is about the same distance away from the diaphragm edge, and this reinforces its diffraction. Better would to have tried to make that have many different distances by e.g. offsetting it in the baffle or the like. The waveguide loading will help but it looks like the tweeter still has good output at 90 degrees given the datasheet curves. This sort of issue is most important when the baffle is small and the driver is also small and symmetrically placed WRT edges. Putting the tweeter in a rather wide baffle with a bit of offset can make this issue go away, but then you have a monkey coffin...
Thanks for the input everyone. I did go ahead and cut these without taking diffraction issues into consideration. I've had these boards for a while and decided to put them to use. The other baffle will need some TLC as there are voids in the bamboo that unfortunately aligned with the woofers recess. I'll have to see how they measure, and can cut new baffles if needed as the baffles will be removable.
I'm not sure I'd be overly concerned about the baffle shape given the tweeter that will be used.
The name of this speaker reminds me of this:
WTF she is using an immersion blender to make mashed potatoes?
The square-ish baffle top edge in the project pic shown above by DrewsBrews would very likely have less of a signature. If you trace from the dome center around the edge you can see that the length changes by about 2:1.
The nice thing about your construction is that you could mock up a baffle shape after mounting the tweeter just by taping on some cardboard of various shapes. Then you could see what shape might improve or result in the least problematic diffraction. You could make that permanent using a plate of plastic or glass or what not, since you do not need to continue backwards (the cabinet is open there. That would save you having to make an entirely new baffle, although you could so that as well. At the same time you can make me look like a fool when the diffraction with the current baffle is not a problem at all! But it is worth taking a look at either way it ends up.
He's using a waveguide loaded ribbon tweeter
Correct. But it has a pretty broad pattern from the MFG datasheet, so it will illuminate the edge just the same. Not as point-source like as a dome, but diffraction control is still worth some consideration I think.
Here is the other baffle, as you can see it needs a little help. I think I'll use the HP portion of JR's Taiga design as a starting point.
Oh snap. That bamboo can really be a PITA. Home Depot is selling some inexpensive 2x4 foot sheets of Hevea (rubberwood) butcherblock. Currently these cost only $79 each:
https://www.homedepot.com/p/Hampton-Bay-4-ft-L-x-25-in-D-Unfinished-Hevea-Solid-Wood-Butcher-Block-Countertop-With-Square-Edge-THD-HBU-0001/319764603
I would dam off the through hole with tape and pour epoxy in the low area. Not sure if anything else will work as well.
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The three times I've used this particular tweeter I found the wave guide and throat depth to be enough that baffle geometry is pretty near moot. There is still an effect, but very minimal.
How do you handle the chamber frequency at 1.5KHz (or do you)?
http://viawave.ru/en/product_850
Looks good on paper and fairly-flat off-axis so charlie's concerns are not unfounded while JR's feedback is welcomed . . .
Adam used it and used guess what, a series notch! He said he did not like it much until he did that.
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How much are these ViaWave tweeter$ delivered and what does the notch filter schematic look like, Wolf?
Are they better than a good pair of ESS AMT-1's?
I bought these used from another local DIYer
Series notch are LCR in series placed across the driver.
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I wuz kinda looking for an actual schematic with component values for the subject tweeter, sir.
. . . And an experienced ear's feedback concerning the comparison between the AMT-1 and the ViaWave 850.
I am trying to learn and the more real data I consume and absorb the more relaxed my mind becomes leading me toward further expense/experimentation.
Viawave are about $300 each. Some people have said they are the next best thing to RAALs. I have never heard RAALs but I know several people on this forum that have and have also used or heard the Viawaves and hopefully will chime in.
The ESS can likely play lower, but have very limited vertical directivity due to their height.
I have not seen the components used in said notch.
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Thanks for the clarity, Wolf.
I'll post in the other thread
Wow, thanks for the tip! I see that Heava is not much harder than cherry, and the edge-glued board should not have voids like the bamboo slabs. Probably use this for baffles instead of solid birch.
My father calls it "Cheap Cherry". He got an unfinished butcher block table of the stuff that he rubbed with BLO. That was probably 30yr ago. I sanded it down to remove some stains from being in storage, re applied the oil and still have it in my kitchen.
From research it comes from rubber tree farms once they reach end of life for rubber production. So they aren't cutting down virgin wood from rain forests to source it at least. Though they may clear forests for the farms... If it isn't one thing then it is another.