Bliesma 25 and 34 look amazing in waveguides. Plus they don't have output bump around Fs. Plus they are back in the game as I can see in shops stocks...
SB26ADC and SB26CDC also, but pitty they fall to under 85 dB.
It is cool how easy is to filter the tweeter when response in waveguide toward high frequencies approximate 6 dB/oct fall...
SB26ADC and SB26CDC also, but pitty they fall to under 85 dB.
It is cool how easy is to filter the tweeter when response in waveguide toward high frequencies approximate 6 dB/oct fall...
Nice! This is the wg of the D3004 (since they have the same faceplate clamping) or a newly developed one for the D2604?
I'm going to try a thumbnail router bit as described here. It starts with a seriously large radius which then decreases gradually to what will fit on the rest of the bit, at a guess sround 2 inches (50 mm) at the tip to about 3/4 inch (19 mm) at the bearing. The large radius will promote the wavefront detaching from the cabinet face before it encounters the smaller radius further along.
Plus it looks more interesting than a simple roundover, which counts in my book.
Agreed. The dome on a large flat panel looks much better than on a smaller 8" baffle.
The 8” wide baffle would result in a peak in output around 3KHz for both the dome with the flat faceplate AND the waveguided dome, as Jim and augerpro have demonstrated.
However, the peaking is worse with the flat faced dome, and less pronounced with the wave-guided dome.
Large bevels or round overs can improve things, but this applies for both the flat faced dome and the wave-guided dome.
An oldie but a goodie:
http://loudspeaker-research.de/Edge Diffraction - Rounding vs Bevel.pdf#page2
Kept digging, to find this link finally working:
http://loudspeaker-research.de/
Lots of interesting links.
http://loudspeaker-research.de/
Lots of interesting links.
The source size (speaker size) has actually also quite a substantial effect on how strong the diffraction effect is.
Especially in combination with certain dimensions of the baffle.
Something that's not shown in this little paper.
@b_force , can you elaborate more on your point of source size in combination with baffle dimensions?
Kinda hard to do in just one simple explanation without quoting entire books.
The simple answer you mostly get, is that there won't be any difference.
The problem is that this a purely simplified theoretical explanation.
One that isn't wrong on itself, but it's missing the point that a loudspeaker doesn't behave like a perfect source.
So often a bigger woofer already starts beaming earlier, which therefor gives less diffraction "ripple" problems.
Also the actual origin of the source could be deeper (further back), therefor changing certain interference patterns.
This is strictly speaking not diffraction itself, but has an effect how it behaves to even a point that it's won't be really noticeable anymore. Or "camouflaged".
(could be an additional benefit at the same time!)
There is also a more practical problem.
With a bigger speaker, the relative distances to the baffle sides change.
Because we won't put a bigger woofer in the same position as a smaller one.
Obviously, strictly speaking, this is not apples vs apples , but rather just a practical consequence.
Especially on the vertical plane.
So my comment was also said from a more practical point of view.
These baffle sims illustrate the effect of driver size on edge diffraction... as b_force was talking about. This is the on-axis response of an ideal flat piston with a diameter of 25mm, 75mm, and 225 mm. Of course, real drivers will differ from ideal flat pistons, particularly when the wavelength is less than the diameter.
Nothing wrong with the vituixcad or edge or Jeff bagby tools, for the purpose intended. But with more complex shapes of baffle and box a 3D fem like tool would help. I also realise the learning curve of such a tool may be blocking.
8" fans rejoice! SB29SDAC, TW29TX, and my first try with the TW29BN (6" incoming). Updated my website with these designs.
Erin H. has them right now. Once I'm satisfied with the performance, I'll be posting it here and at my website. Prototyping the center channel right now.