I have now lived and listen a lot to these the past days. I still very much enjoy them and I'm certainly glad I built them. But all isnt/wasnt completely dandy - is it ever
Yes- there was harshness in the midrange. So the old CD / wg problem? I dont know. Its like a shsss bright guurlgle on choir and massed strings - impossible to live with. I think it can what is circled in the "bugger" attachement - it could be energy transfer in both any direction... its surely is in the cover region.... For the Hornflower, I fixed 2/3 of it by some very simple measures and I have one or two left up my sleeve.
- The cavity between the horn and the flower - filled it up with fleece - better.
- Made a roll of fleece which on one of the long sides, I cut small leafs - these kind of prolonged the round-over of the wg towards the flower - better still.
- The hard brutal PLA/Concrete/Steele meeting between the flower and the WG in the area of the throat - I used felt to to form a gasket which the WG now rest mostly on to decouple them from each other - that made 2/3. Very nice thank you.
I will make some more investigations around this - I isolated it by playing a foul passage and did it with only LP or HP section. It was the HP for sure. But there seem to be a combination of mechanical interaction and diffraction that was the reason.
Remaining things:
- The tube inside the flower which the CD / WG sit in will be dressed with the same felt mat on both inner and outer sides i.e. facing the bass drivers and the CD/WG (the latter could be made better than my quick fixe above).
- Rolls on the four tops of the flower to mitigate diffraction by absorbing HF thus hindering it reaching the 4 eye-brows and at the same time support some covering of the backside for some improved WAF.
- I will make the petal leafs a bit more ordered and permanent. Color and style is under consideration...
I'm enjoying them immensely and they are a real hit - super duper. As I write this I listen to Aja and I hear a lot of how it was played - especially in the bass actually - thet bassist plays many more notes than I knew - quick little wonderful arpeggios that I haven't even spot in my HPs :-D
I will get back on my main takeaways from this bild + one aspect that will never be possible fix (but it's ok...).
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Hi,
I've been pondering about some weird sound somewhere on treble on my system and only lately started paying attention to it again. It is likely that my printed ST260 has audible resonance, as it is quick proto and there is audible ring when knocked.
When I got the waveguides I tried to address possible ring by taping some damping behind it, like you with the fleece, but couldn't say if there was a difference. Also measurements didn't seem to show much, at least nothing obvious, so didn't pay too much attention to it until lately.
Turns out there is quick and simple test to evaluate audibility of ringing on such freestanding waveguides: just stand in front of the speaker, play music and listen and hold the rim of the waveguide (or any part of the waveguide) with your fingers to tame any resonance
To make sure your arms do not change the sound keep them still, like rest of your torso, just pinch your fingers to dampen resonances, and relieve to let it resonate again. There seems to be quite much coloration in my case at least, one piece petg print with 20% infill if I remember. For some reason, the audible difference seems much greater than what measurements show. Perhaps I took wrong measurements, perhaps I didn't zoom close enough, perhaps it is below noise floor or something, or the issues is such that it averages out for mic but not for ear. I should try mic measurement with the finger technique, as there is confirmed audible difference perhaps it is possible to now see it on some graphs as well, to get better understanding on magnitude of things.
Anyway, it is easy to think good measurements mean system performs well, even though there can be issues under the surface which take away from the performance. Same for box noise for woofers.
Remembered your post so thought to post about it here. If you try it and hear difference with yours, please post
ps. Getting to know magnitude of things is interesting in itself, reaching your arms to take the pinch changes the sound considerably, very strong reflection with very audible effect, so it is important to stay still. Makes you wonder that any object near (front) of the waveguide must affect the sound, possibly quite a lot. Ask a friend or family member to move behind the speaker while listening to have clue what magnitude effect stuff behind the speaker has ?