While slowly working on my other MEH projects, I just noticed the Ikea Kallax in front of myself and I just thought it would be cool to fit in a synergy horn there. The internal dimension of the kallax cell are 330 x 330 x 380 mm, so the speaker must fit into this volume including wires in the back. This is nothing new, it has been done before, e.g. this one by aragorus https://www.diyaudio.com/community/...-6-5-coax-in-a-reflex-box.353906/post-6190455 would most probably fit the shelf.
Coaxial is the obvious option, but I would like to try if I can fit in the GRS PT 6816 planar tweeter in there...
And if necessary, I can add a bass unit to a shelf cell below. Not that I would necessarily use the speakers inside the shelves, but it is a quite handy size and a bit of a challenge🙂
Coaxial is the obvious option, but I would like to try if I can fit in the GRS PT 6816 planar tweeter in there...
And if necessary, I can add a bass unit to a shelf cell below. Not that I would necessarily use the speakers inside the shelves, but it is a quite handy size and a bit of a challenge🙂
V1 - 60 x 36 horn would fit.
This would be just a standard thing. However, since this is a planar driver, I might actually try to get some inspiration from Yorkville SA-102 - and use the ribbon horizontally. Maybe not the best idea, but I try it at least in 3D🙂 It would make fitting a woofer easier.
Or maybe I will try assymetrical vertical coverage first. The ribbon is quite directional anyway...
This would be just a standard thing. However, since this is a planar driver, I might actually try to get some inspiration from Yorkville SA-102 - and use the ribbon horizontally. Maybe not the best idea, but I try it at least in 3D🙂 It would make fitting a woofer easier.
Or maybe I will try assymetrical vertical coverage first. The ribbon is quite directional anyway...
I´ve seen a guy use a 2x1 Kallax to mount 2x12" woofers in the middle of them so they end up as H-frames.
That could round out your speaker visually.
Only problem I see is fixing the baffle into the middle of the Kallax and giving it weight and structure.
Those things are super light and well mostly hollow. Sealed might be the better&easier way to go
Kallax H-frames
That could round out your speaker visually.
Only problem I see is fixing the baffle into the middle of the Kallax and giving it weight and structure.
Those things are super light and well mostly hollow. Sealed might be the better&easier way to go
Kallax H-frames
I would not use the shelves, I do not think the quality is good enough for anything beyond a small full range box. I use that only for size reference.
The Yorkville inspired horn has (as expected) most space for the woofer. It could even fit an 8" woofer and the bass reflex ports / vents can be placed at the front easily. I wonder how much of a problem is the asymetry. And maybe using this horn laid on its side would be better?
If I moved the GRS PT 6816 flange into the corner, I would get an asymetric horn in both directions - and then theoretically 4 of them could be stacked together...in a 2x2 Kallax shelf🙂
If I moved the GRS PT 6816 flange into the corner, I would get an asymetric horn in both directions - and then theoretically 4 of them could be stacked together...in a 2x2 Kallax shelf🙂
I'll be very interested to see how the PT6816 behaves in a horn like this if you actually build it 🙂
Lately I've been very into trying to combine a short WG loaded line source with a low x-over to a tower type speaker. My first prototype was just 6x the SB65WBAC in a tapered line 2+2+2 with the two ends slightly attenuated above 3k in a simple straight 90º horn. Worked very well down to about 800Hz, where it lost directivity due to the small dimensions (about 35cm wide mouth, 14"), wihtout any help from synergy-ports.... A bit ragged in the response above 8k, but they did sound very good overall.
I actually thought about combining the PT6816 with two 4" mids in a synergy 🙂 - but never got around to ordering them.
Lately I've been very into trying to combine a short WG loaded line source with a low x-over to a tower type speaker. My first prototype was just 6x the SB65WBAC in a tapered line 2+2+2 with the two ends slightly attenuated above 3k in a simple straight 90º horn. Worked very well down to about 800Hz, where it lost directivity due to the small dimensions (about 35cm wide mouth, 14"), wihtout any help from synergy-ports.... A bit ragged in the response above 8k, but they did sound very good overall.
I actually thought about combining the PT6816 with two 4" mids in a synergy 🙂 - but never got around to ordering them.
I built one with ESS AMT ams two 3FE22s, it works really well. It is a bit larger and heavier, so I would actually like to build a smaller one with the GRS PT.
I wonder if Eminence Alpha 8 or Fane Sovereign 8-225 would be suitable woofers for this application. BC 8PE21 was usable (without a back cover) up to around 800 Hz in my Runt clone. Here the woofer entry ports can be closer to the apex. Even a single central port should allow crossover around 600 Hz without any trouble. Time to fire up Hornresp and do some simulations.
Second version is a perfect fit. The flange will be most probably machined from plywood for the final horn, but the back chamber will be definitely 3D printed.
looking good, the asymetrical horn should work well in a high shelf. The response will be very narrow in the horizontal plane though from the planar.... mad idea could you make a phase plug for it to bring it to a more narrow throat?
With 3D it should be possible - but I do not know how it should look like. Could you please make a hand sketch so I get the idea better?
Fun stuff. I would be really careful adding anything like a “phase plug” in front of a planar tweeter as it tends to mess up the smooth response. Maybe vanes like a Smith horn might work? Even the throat area needs to be more of an wider expansion waveguide vs narrow throat. Maybe open up the top wall by 10deg more so not a perpendicular wall?
The objective of the phase plug would be to equalise the length of the diaphragm in the long dimension (2D) to a smaller throat while preserving a horn area expansion rule. Here is a conventional phase plug for a dome compression driver:
The basic idea would be equalise the channel lengths by making channels closer to the center have more bends to increase their length. Also the channels need to expand in area correctly. I'm very bad at drawing but something like this:
We can simulate such things in AKABAK 3 now 🙂
Jack Oclee-Browns PhD thesis looks like it would have lots of useful info on phase plug design.
Maybe something like this? https://goopics.net/i/g8qous
From this thread: https://www.diyaudio.com/community/...-be-used-in-a-line-array.380788/#post-6898566
@xrk971: It is hard to see, the top angle is around 10 degrees, the bottom angle is 40 degrees. I saw this arrangement at Yorkville SA-102 - but use a planar driver instead of a paraline.
From this thread: https://www.diyaudio.com/community/...-be-used-in-a-line-array.380788/#post-6898566
@xrk971: It is hard to see, the top angle is around 10 degrees, the bottom angle is 40 degrees. I saw this arrangement at Yorkville SA-102 - but use a planar driver instead of a paraline.
Last edited:
Too late to edit. I just thought if there was any advantage to tilt the planar driver bottom slightly backwards, so that it is symmetrical wrt the first expansion...it might be possible with a bit of effort.
In reference to post #16 perhaps you could make the horn into a kind of multi cell by extending the vanes? I'm not sure of the limitations of these vanes....