Yes one reason I wanted to try the elliptical mouth was to help driver offset. That it ended up being the best measuring was just icing on the cake. All of my designs now are elliptical mouths for these reasons.
I also moved the screw holes a few months ago just so I could cut into the bottom flange a bit just as you said.
SB26ADC in 5" G and SB21SDC in 5" A in .STEP format, which should be easier for the CNC people:
Dropbox - 5x.75 G SB26 v5.step
Dropbox - 5x.75 A SB21 v5.step
And SB26ADC in 8" C, .stl and .step:
Dropbox - 8x1.5 C SB26 v3.step
Dropbox - 8x1.5 C SB26 v3.stl
Dropbox - 5x.75 G SB26 v5.step
Dropbox - 5x.75 A SB21 v5.step
And SB26ADC in 8" C, .stl and .step:
Dropbox - 8x1.5 C SB26 v3.step
Dropbox - 8x1.5 C SB26 v3.stl
Ah, didn't read it fully
-another reason why the deeper profile (1.5") isn't showing the characteristic dip of a fully concentric (round) design that I'd expect.
Well done!
Hmmm... You are quite correct. I have rather confused myself with the cost of printing at the local hackspace shop. I checked a quote for an SLS print of a pair of your waveguides from a random commercial supplier and it was £432. At £20 or so for a pair it makes sense but obviously not at twenty times the price. Interesting and more thought required.
One option I considered early on was to mill two scallops into the waveguide wall. Then design the phase shield separately that had matching ends so it could be keyed to the waveguide in perfect alignment. That way you CNC the waveguide, but have a high quality print done of the phase shield.
Watching with interest, and hoping for a group buy.
BTW, thanks for geting me back into 3d CAD - As a proud sb26stac owner, I'm hoping to edit 5" WG file just to keep the eliptical inner WG shell, and add a rectangular face to it for easier mounting onto baffle.
Also, fingers crossed for a satori 6.5" WG to match with bigger satori midrange driver. Coupled with ferrite tw29 I'm looking at a world class 1st order elliptical xo.
BTW, thanks for geting me back into 3d CAD
- As a proud sb26stac owner, I'm hoping to edit 5" WG file just to keep the eliptical inner WG shell, and add a rectangular face to it for easier mounting onto baffle. Also, fingers crossed for a satori 6.5" WG to match with bigger satori midrange driver. Coupled with ferrite tw29 I'm looking at a world class 1st order elliptical xo.
Is it purely the size, or is off axis more important?
Because, new Satori dome is holding it up a bit better off axis, and any Wg that makes it to 15khz is fine by me. Satori is a wonderful dome that begs for constant directivity WG imho. Lets not forget Be dome ($$$)...
edit: new sb26 ceramic dome is very very nice
Because, new Satori dome is holding it up a bit better off axis, and any Wg that makes it to 15khz is fine by me. Satori is a wonderful dome that begs for constant directivity WG imho. Lets not forget Be dome ($$$)...
edit: new sb26 ceramic dome is very very nice
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The size of the throat is the main problem. Look at the SB29 results above. It has identical dimensions of the surround and dome as the Be Satori's. OTOH the metal dome will behave slightly different than the fabric SB29, but given what I've seen so far I doubt that will be an improvement. I think SB has a SB26 made with Be, but I don't know if it was ever going to filter into the DIY world.
..from Zaph's (near the bottom of the page):
Zaph|Audio
SB29RDCN (..dimple dome)
no waveguide:
http://www.zaphaudio.com/temp/SBAcoustics_SB29RDCN-C000-4-FR-0-15-30-offaxis.gif
vs. 8" round waveguide:
http://www.zaphaudio.com/temp/SB29RDCN-C000-4-PE8waveguide-0-15-30-45-60.gif
"Not too bad, though there are some response artifacts on the top end. The waveguide was modified in the same way as the version in the waveguide TMM system on this site. The dimple dome has a bit wider surround than the 27TDFC and the waveguide sits slightly over the edge surround, though not touching it. I suspect that the response artifacts are more related to the waveguide profile near the dome and the unique radiating surface
..The SB29's unique radiating surface mates well to the 8" PE waveguide, much like the 10". The response is smooth and controlled over most of the range, with only a small response issue at the top of the top octave, and then only on axis. I wanted to better describe the fitup. First the opening is actually 1.610", not the 1.5" I previously mentioned. The SB29 neo's flange raises the plastic waveguide edge over just over the outside surround edge and it clears contact by about 1/32" all the way around. The small neo flange is not removeable and so this kind of fitup is pretty much required. I did inspect the large non-neo SB29 for fitup with it's faceplate unscrewed and removed. For those who wish to try this, the opening will need to be cut to 1.750" to clear the surround and press against the plastic dome mount. No guarentees if that arrangement will work as well, but I'd like to see someone give it a shot. (if I don't myself) "
I think printing the phase-shield is a good idea, but then setting it in a "quick-release" silicone form and using a pour-in filler for the rest of the waveguide.
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