@next667
To me it was rather helpful to learn what the different steps are 'doing' in terms of directivity control.
However, some of the eliptical waveguides I worked on were quite ok anyway. For example th eone described here (sorry, again in German).
Very briefly:
The eliptical WG
The quarter model to get an idea of the contour
SPL in an infinite baffle
Horizontal directivity in infinite baffle
Directivity from 2-20kHz with -6dB highlighted by lines
...and in an enclosure
Please note, that these simulations have been done using an 'ideal' flat membrane at the WG throat in order to concentrate on the impact of the WG contour first.
The tricky thing is then to adapt a WG to a specific tweeter, i.e. to a dome, invers dome or ring radiator. and to adapt the directivity of the WG to the directivity of a specific bass-mid-driver.
The observation, that a small 'step' at the WG throat is extremely helpful to achieve a constant directivity at higher frequencies was a result of the subsequent work on simulating domes, inverse domes, ring radiators etc...
I did relatively detailed analysis of what's ongoing with the DXT-contour here and here.
To me it was rather helpful to learn what the different steps are 'doing' in terms of directivity control.
However, some of the eliptical waveguides I worked on were quite ok anyway. For example th eone described here (sorry, again in German).
Very briefly:
The eliptical WG
The quarter model to get an idea of the contour
SPL in an infinite baffle
Horizontal directivity in infinite baffle
Directivity from 2-20kHz with -6dB highlighted by lines
...and in an enclosure
Please note, that these simulations have been done using an 'ideal' flat membrane at the WG throat in order to concentrate on the impact of the WG contour first.
The tricky thing is then to adapt a WG to a specific tweeter, i.e. to a dome, invers dome or ring radiator. and to adapt the directivity of the WG to the directivity of a specific bass-mid-driver.
The observation, that a small 'step' at the WG throat is extremely helpful to achieve a constant directivity at higher frequencies was a result of the subsequent work on simulating domes, inverse domes, ring radiators etc...
Attachments
I'll get it posted tomorrow morning, unless Matthias sees this and posts it first.
I have. Haven't measured it yet though, I've been swamped with overtime and house work. I have some vacation in June and should be able to measure it.
If you look carefully its not bigger than mw13, actually I'd say its regular 104mm size... USXX commented on danish forums that simple conical is usually best, and that stac is designed to be wg loaded...
you can also see new 2.5" satori mid - Waveguide that haha
Can't say I'm terribly impressed with those. One is so small, the other so large, and both are circular for maximum CTC to the midrange
Still, having a factory option is VERY welcome. OTOH the mid-dome has me drooling. I have half finished speakers using the fantastic TangBand 3" dome, which promptly went NLA. Hopefully these will surpass the TB, the 2.5" is a good start, the 3" domes are surprisingly directional above 2khz. Those look fantastic! Any issues with fitment,etc?
I like that wall contour, sort of JBL M2-esque. How did you model that?
Here is the step file to the 5" waveguide for the Scanspeak tweeters: Dropbox - 5x.75 A_cnc v3.step - Simplify your life
Thanks.
But I'm using your 6" waveguide for the SB26ADC SB Acoustics tweeter. The file was named "6x1 B v2.stl".
Maybe your can upload the step file of these waveguide, please?
No problems at all! The fit is just perfect. Just a gentle push and the tweeters would hold on to the on the three "ridges" on the waveguides by themselves. I'd still use the screw holes for real use, but it shows how good the fit is.
I keep meaning to get my website rebuilt, so it would all be there, with commentary, plots, etc. Just haven't done it yet. I'm working night shift over the next 5 days so I'll see what I can get done then. I REALLY wish diyaudio would just allow edits to posts and I'd update the first post.
Thanks a lot next667!
Kudos go to augerpro for his ongoing fantastic work here.
I'm really happy to support as far as possible. However, very little time actually. So, please be patient, if I respond with delay.
I'm working on a WG for an AMT actually. A bit slow, but I update in teh German forum from time to time. WGs for dome tweeters are very well covered here by augerpros work...
Kudos go to augerpro for his ongoing fantastic work here.
I'm really happy to support as far as possible. However, very little time actually. So, please be patient, if I respond with delay.
I'm working on a WG for an AMT actually. A bit slow, but I update in teh German forum from time to time. WGs for dome tweeters are very well covered here by augerpros work...
I agree that shaving some space to allow close mounting of the tweeter and midrange driver makes sense in general.
However, I just realised that with the drivers used in the Monkey Coffin project, the distance between the tweeter and the midrange is limited by the size of the (huge!) magnet of the midrange driver, not by the waveguide. I would therefore be very interested in a round version of the Scan Speak waveguide. Basically a "clone" of the WG148 would be cool. The advantage of this would be that it's easier for builders to make a circular cut-out of on the baffle, and it would be easy-peasy to fit the Scan Speak tweeter to the waveguide (which is a bit tricky with the WG148).
How much work would it be to modify the existing oval design (for example the 5" version A) to a circular waveguide with an external diameter of 148 mm?
Sure! I'd guess it would work out similar to a WG148.
I might just have a go at it and compare measurements from the circular and oval versions, and also the WG148 (which I modified to fit the Scan tweeter).
Is there any significant changes made between v2 and v3?
(I hope not, because yesterday the v2 version came printed out
)