I just tore out small pieces of a Magic Sponge and inserted into the holes. Some pieces even kept popping out of the hole and ended up above surface level as you can see in the picture. Doesnt seem to matter much as the effect is quite good. (I try to restrain myself with the flowery language as I am pretty pleased and excited about the result).
I wonder if the Magic Sponge would work as well filling a single large hole instead of an array of small holes.
Note about CMI inspiration - in CMI, the holes were angled to expose less of an opening to sound waves traveling out from the throat.
Note about CMI inspiration - in CMI, the holes were angled to expose less of an opening to sound waves traveling out from the throat.
Sorry, I should have asked if they are angled. How much? Is that angle carried back all the way to and through the mid mounting and enclosure sides?
The midrange enclosures are close to normal to the sides of the horn walls. Then the array of holes are angled outwards 25-30 degrees.
Did a simple EQ to sum the mids and the compression driver. Used 20 degrees as reference. A high shelf and a peak EQ on the compression driver and two low shelfs in series on the mids. Using the room EQ funktion in RME Totalmix.
Here is 0-50 degrees 1 meter. 9 ms gate. No FDW.
This is 100-110 Euros worth of drivers. And the @mabat 520 horn. (hacked to death by me - sorry!)
Here is 0-50 degrees 1 meter. 9 ms gate. No FDW.
This is 100-110 Euros worth of drivers. And the @mabat 520 horn. (hacked to death by me - sorry!)
No HP filter on the compression driver its the natural roll off beeing close to 24 dB/oct.
The mids got two lowpass Q 0.7, one at 800Hz and one at 1000Hz. This resultet in a close to 24 dB/oct roll off.
The raw response is in an earlier post:
https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-7993608
This was just to see if the drivers sum off axis. Which is the beauty of a MEH.
Will optimize later, there is no delays and the compression driver needs more protection I guess.
The mids got two lowpass Q 0.7, one at 800Hz and one at 1000Hz. This resultet in a close to 24 dB/oct roll off.
The raw response is in an earlier post:
https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-7993608
This was just to see if the drivers sum off axis. Which is the beauty of a MEH.
Will optimize later, there is no delays and the compression driver needs more protection I guess.
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so basically the dip in the CD results from tube resonance of the mid entry ports. also, you lost quite some sensitivity at the bottom ~ 4 dB
I printed the A460G2 to use with the 2535, but there's so little difference in the published directivity that the A400G2 should perform equally well, plus it would use less filament and print faster. If I was restarting today I'd do the 400.
Unless Mabat ever issues the dedicated 2535 horn he teased a while back then delayed.
Unless Mabat ever issues the dedicated 2535 horn he teased a while back then delayed.
Performance-wise, there's such a small difference that it probably doesn't make sense. I wanted to do this as I wanted something including a stand, etc., but was never quite satisfied. So, currently I don't work on it anymore.
So far I always used a sponge brush, don't know why. But it's dirt cheap and works fine. - Actually, maybe the last time I used an ordinary (disposable!) brush, it doesn't really matter, as you need to sand it afterwards anyway, at least the first coat.
Tritonia-μ
140 x 122 mm, 110° nominal coverage
This is for 1" throat. I will also make a few more versions for smaller drivers than this (0.63", 0.5"?).
140 x 122 mm, 110° nominal coverage
This is for 1" throat. I will also make a few more versions for smaller drivers than this (0.63", 0.5"?).
question to the round. What is your preferred setup for printing your ath4 developed horns with 3d printer?
I had good results with wall thickness of about 1,5cm and PLA 60% Infill Gyroid.
But I did not try other fillament and setup. What about PETG,ABS and TPU?
Anyone used these? TPU maybe as it´s a bit flexible maybe will resonate less then the others?
I had good results with wall thickness of about 1,5cm and PLA 60% Infill Gyroid.
But I did not try other fillament and setup. What about PETG,ABS and TPU?
Anyone used these? TPU maybe as it´s a bit flexible maybe will resonate less then the others?
1.5 cm would be massively thick walls! Did you mean 1.5 mm? As I recall in a long-ago post Mabat recommended printing them much lighter. My A460's were printed in white PLA with 2 perimeter walls and 15% adaptive cubic infill for the petals and base parts. The thick section of the petals makes them plenty stiff IMO. I used three perimeter walls and the same infill for the driver adapter pieces for extra strength, since that has to support the driver and the horn. I used about 4 kg of filament for the pair of horns including my self-designed mounting brackets. The throat piece of the adapter is printed in gold silk PLA as an aesthetic accent, it's not structural at all so the reduced strength of the silk PLA is no problem.
The parts were glued up with clear '30 minute' two part epoxy and allowed to cure overnight. Squeeze-out was easily removed with isopropyl alcohol, the slow cure gave plenty of time for cleanup to minimize any sanding later on. For now I am using the horns unfinished, and may or may not ever bother to paint them. I'll see how they age.
Bill
The parts were glued up with clear '30 minute' two part epoxy and allowed to cure overnight. Squeeze-out was easily removed with isopropyl alcohol, the slow cure gave plenty of time for cleanup to minimize any sanding later on. For now I am using the horns unfinished, and may or may not ever bother to paint them. I'll see how they age.
Bill
A hole punch kit works nice for cutting melamine foam, simply rotate as you press downward on the foam.