Over the weekend I came up with what seems to be a fairly innovative (albeit obvious) waveguide geometry.
I really wasn't expecting this to work, but it looks like it does, so thought I'd share it here.
What I came up with are triangular waveguides. Attached are some photos of the waveguide, reports generated using ATH and ABEC, and the 'raw' predicted response.
Here's pics of the simulated waveguide, and what was simulated in ABEC (with an enclosure.)
normalized horizontal polar response and acoustic impedance
normalized vertical polar response and acoustic impedance
raw horizontal polar response
raw vertical horizontal polar response
If I were using one of these triangular waveguides in a project, I'd generally have the pointy end facing UP not to the right. If you're in the same boat, then when you look at these sims, swap the "horizontal" and "vertical" sims. Note that the horizontal and vertical response are virtually identical. Which was quite a surprise, I was expecting the triangular shape would cause the waveguide to be shaded towards the widest end. But as you can see in the sims, this doesn't seem to be the case.
I really wasn't expecting this to work, but it looks like it does, so thought I'd share it here.
What I came up with are triangular waveguides. Attached are some photos of the waveguide, reports generated using ATH and ABEC, and the 'raw' predicted response.
Here's pics of the simulated waveguide, and what was simulated in ABEC (with an enclosure.)
normalized horizontal polar response and acoustic impedance
normalized vertical polar response and acoustic impedance
raw horizontal polar response
raw vertical horizontal polar response
If I were using one of these triangular waveguides in a project, I'd generally have the pointy end facing UP not to the right. If you're in the same boat, then when you look at these sims, swap the "horizontal" and "vertical" sims. Note that the horizontal and vertical response are virtually identical. Which was quite a surprise, I was expecting the triangular shape would cause the waveguide to be shaded towards the widest end. But as you can see in the sims, this doesn't seem to be the case.
Here's the ATH model
The secret sauce is this formula here:
Coverage.Angle = 22 + 27*cos(1.5*p)^2 - 5*cos(p)^2
in particular, the fractional exponent gets you a waveguide with a number of sides that's equal to double the number here:
[angle] * cos ([number of sides]*p)^2
For instance, "45 * cos (1.5*p)^2 will get you a three sided waveguide
change the number to "2.5" and you'll get a five sided waveguide, etc
The secret sauce is this formula here:
Coverage.Angle = 22 + 27*cos(1.5*p)^2 - 5*cos(p)^2
in particular, the fractional exponent gets you a waveguide with a number of sides that's equal to double the number here:
[angle] * cos ([number of sides]*p)^2
For instance, "45 * cos (1.5*p)^2 will get you a three sided waveguide
change the number to "2.5" and you'll get a five sided waveguide, etc
Attachments
Here's a few ideas on how these waveguides can be useful.
Triangular seem nearly ideal for putting a speaker into the corner of a room. A bit like the Klipschorns, but with a triangular waveguide you can keep the height to a minimum, since the angled baffle aims the wavefront towards the center of the room.
If using a two way, it also allows for the "Gradient Trick" of aiming the off axis nulls further out into the room, instead of having them right by the speaker itself.
Triangular seem nearly ideal for putting a speaker into the corner of a room. A bit like the Klipschorns, but with a triangular waveguide you can keep the height to a minimum, since the angled baffle aims the wavefront towards the center of the room.
If using a two way, it also allows for the "Gradient Trick" of aiming the off axis nulls further out into the room, instead of having them right by the speaker itself.
There are 18 traces... is this every 5 deg or is it the full 180 deg panorama? Legend was missing. And as it is asymmetric, its of interestraw horizontal polar response
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But then we only know the half of it as it is not symmetric around the vertical axis!? In this particular case, don't you have to do the full 180 to understand the WG directivity properties? It will not "sound" the same standing to the left or right of on axis...
For the speaker ngy4wG2.png, is the 90 deg data from the right or left side?
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For the speaker ngy4wG2.png, is the 90 deg data from the right or left side?
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