If it were self-supporting, I kind of like the results of your shape here. You could created internal passages (trough holes) for a few threaded rods and use butyl in-between enclosures.
It all depends on your own vision, but with a sleek metal frame below it, and self supporting cabinets (no frame around it) it could have a somewhat industrial appearance.
That frame below could be in the style of the current desk around the TV. Very Scaena-ish
It all depends on your own vision, but with a sleek metal frame below it, and self supporting cabinets (no frame around it) it could have a somewhat industrial appearance.
That frame below could be in the style of the current desk around the TV. Very Scaena-ish
The original idea was to connect all the cabinets to each other through a threaded bar and nuts, uncoupling with butyl rubber discs (or sorbothane to exaggerate) which should be housed in the circular slots shown in the picture.
This would theoretically also allow each enclosure to be rotated freely, in order to minimize comb filtering by exploiting the horizontal response of the speakers.
This is the only measurement I was able to make at the listening position (smoothing 1/24dB), without subwoofer.
Some notes.
Thanks!
Manuele
This would theoretically also allow each enclosure to be rotated freely, in order to minimize comb filtering by exploiting the horizontal response of the speakers.
This is the only measurement I was able to make at the listening position (smoothing 1/24dB), without subwoofer.
Some notes.
- I need to repeat the measurements to understand what's happening below 1k, while below 300 Hz it's room dominated, the band between 300-1,000 Hz need to be investigate with outdoor measurements of the speaker itself.
- I would not have expected such behavior at high frequencies. Maybe the minimal baffle size helps to amplify only the high frequencies so as to counteract the comb filtering.
Thanks!
Manuele
I think that's a pretty good idea.
But to quickly compare the above to what Vituixcad thinks:
I see a lot of similarities here. Your baffle shape is going to change the top end a bit, no doubt. But look at the step up
in frequency at ~1.5 KHz, I think it's quite usable. See the rar file attached. Adjust the positions of the drivers and room to the right
sizes and let's check it out. You may need to point to the TC9 driver files again, as I'm not sure my folder still has the same name.
P.S. the driver at zero height is the center driver with a 0 Y-measurement. Microphone is at 0, floor at -1000. Adjust the floor and ceiling
to real positions but keep the mic at zero.
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Thanks Ronald!
I downloaded the Vituixcad model several months ago and played with it for (very little) time and I got very similar results to yours (of course!).
I just need to check that I haven't moved the position of the microphone from zero! Thank you for the advice!
I'll rerun the simulation using your files to see if I can find the reasons of the uneven response below 1kHz.
Due the shape of my enclosures, I'm still having the insane desire to perform a multi-physics simulation with Comsol of the external acoustic field + mechanical modal analysis but I don't think I'll ever find the time
Can the code you mentioned, ABEC, simulate something like my "weird" speakers as good as Comsol in a faster way?
Thanks, Manuele
I downloaded the Vituixcad model several months ago and played with it for (very little) time and I got very similar results to yours (of course!).
I just need to check that I haven't moved the position of the microphone from zero! Thank you for the advice!
I'll rerun the simulation using your files to see if I can find the reasons of the uneven response below 1kHz.
Due the shape of my enclosures, I'm still having the insane desire to perform a multi-physics simulation with Comsol of the external acoustic field + mechanical modal analysis but I don't think I'll ever find the time
Can the code you mentioned, ABEC, simulate something like my "weird" speakers as good as Comsol in a faster way?
Thanks, Manuele
ABEC can do it, no doubt. It takes quite a bit of processing power and some preparation of the model to do it.
The time it takes will depend partly on the polygon count. The accuracy will also depend on that.
As said, I didn't do it myself, @fluid was the one experienced and willing to do it for me. I had the plan to examine that road myself,
in other words, learn the ins and outs of ABEC but never got around to it.
It might be easier and even more accurate to measure the box(es) itself, if you have the room to have enough of a reflection free gate.
Or more ideally, measure outside on a high pole.
I've only ever done inside measurements of my arrays and dissected them thoroughly, scanning them a micro second at a time to try and learn
what truly happened between direct sound and the room answer. It gave me enough of a feel for it to be able to go a step further with DSP.
It wasn't until I joined the simulation fun of nc535, that I started to grasp the "why" part of what I had seen.
The results in a room are rather complex, but the simulation tools sure help to make sense of it.
The time it takes will depend partly on the polygon count. The accuracy will also depend on that
.As said, I didn't do it myself, @fluid was the one experienced and willing to do it for me. I had the plan to examine that road myself,
in other words, learn the ins and outs of ABEC but never got around to it.
It might be easier and even more accurate to measure the box(es) itself, if you have the room to have enough of a reflection free gate.
Or more ideally, measure outside on a high pole
.I've only ever done inside measurements of my arrays and dissected them thoroughly, scanning them a micro second at a time to try and learn
what truly happened between direct sound and the room answer. It gave me enough of a feel for it to be able to go a step further with DSP.
It wasn't until I joined the simulation fun of nc535, that I started to grasp the "why" part of what I had seen
.The results in a room are rather complex, but the simulation tools sure help to make sense of it.
The simulation-way is certainly interesting, but at this stage it's better to measure the actual box(ex) as you suggest.
I will try to measure the single box outside, as far as I can from the outer walls and floor. I hope not to do any damage!
I need a mini amplifier to do this, it is not wise to take my Marantz outside...
I played a bit with your Vituixcad file and I've noticed that there are two resistors for the three upper and lower speakers. Are those related to the power shading necessary to improve the vertical response? Changing those resistance values have not improved the vertical response in my simulation.
I also tried to add some frequency shading but the situation doesn't improve much...
Is there a way with some frequency and/or frequency shading combination that can improve the vertical response?
Thanks,
Manuele
I will try to measure the single box outside, as far as I can from the outer walls and floor. I hope not to do any damage
!I need a mini amplifier to do this, it is not wise to take my Marantz outside...
I played a bit with your Vituixcad file and I've noticed that there are two resistors for the three upper and lower speakers. Are those related to the power shading necessary to improve the vertical response? Changing those resistance values have not improved the vertical response in my simulation.
I also tried to add some frequency shading but the situation doesn't improve much...
Is there a way with some frequency and/or frequency shading combination that can improve the vertical response?
Thanks,
Manuele
It's supposed to look like this:
And that's what I still see when I download it...
However, I did play briefly with some filtering, more elaborate than using a resistor by itself, but only managed to widen vertical output up to 5 KHz,
unless using a single driver as tweeter up top, which destroys the pattern control completely. So I wasn't successful in what I wanted to try and achieve.
I didn't try delay and shading to mimic a CBT, I don't like using shading that way. I'd say we need as much support for the bottom end as possible.
So what I tried was frequency shading, but it stays too narrow above 5 KHz no matter what I tried.
If you look at the unfiltered result:
you see the red line moving up from about 4 KHz, that's the directivity index. I'd want it to continue smoothly up, not with a jump like that.
See my own 25 driver array:
While it does jump a bit, it's never more than 1 dB and continues to rise rather smoothly. That jump has to do with
lobing due to the distance between sources.
And that's what I still see when I download it...
However, I did play briefly with some filtering, more elaborate than using a resistor by itself, but only managed to widen vertical output up to 5 KHz,
unless using a single driver as tweeter up top, which destroys the pattern control completely. So I wasn't successful in what I wanted to try and achieve.
I didn't try delay and shading to mimic a CBT, I don't like using shading that way. I'd say we need as much support for the bottom end as possible.
So what I tried was frequency shading, but it stays too narrow above 5 KHz no matter what I tried.
If you look at the unfiltered result:
you see the red line moving up from about 4 KHz, that's the directivity index. I'd want it to continue smoothly up, not with a jump like that.
See my own 25 driver array:
While it does jump a bit, it's never more than 1 dB and continues to rise rather smoothly. That jump has to do with
lobing due to the distance between sources.
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Thanks for your help!
I had the same feeling during my simulations. I need to understand how audible this problem is from my listening position, in my room.
Now the dilemma is: should I keep beating my head looking for a reasonable compromise solution (a good mental challenge!) or print another 32 boxes (and buy another 32x TC9) to create a true "Infinite Line Array" (it would be also ideal from an aesthetic point of view...)?
Another possible solution, Scaena-style, would be a ribbon / planar tweeter column, but the cost could be even higher than the first solution and I don't know if the result would be better...
You've already shown me the simulation with 15 modules, so I don't think it's worth trying to make a 16-box Line Array, right?
Thanks,
Manuele
I had the same feeling during my simulations. I need to understand how audible this problem is from my listening position, in my room.
Now the dilemma is: should I keep beating my head looking for a reasonable compromise solution (a good mental challenge!) or print another 32 boxes (and buy another 32x TC9) to create a true "Infinite Line Array" (it would be also ideal from an aesthetic point of view...)?
Another possible solution, Scaena-style, would be a ribbon / planar tweeter column, but the cost could be even higher than the first solution and I don't know if the result would be better...
You've already shown me the simulation with 15 modules, so I don't think it's worth trying to make a 16-box Line Array, right?
Thanks,
Manuele
I don't think I would go for anything but the tall arrays. Does that answer the question?
About the looks, well... that's quite a personal preference related issue. I don't think a self supporting row of that enclosure you showed would be ugly in my eyes. But I didn't particularly like the look with a frame around it. As said, it may be personal preference.
About the looks, well... that's quite a personal preference related issue. I don't think a self supporting row of that enclosure you showed would be ugly in my eyes. But I didn't particularly like the look with a frame around it. As said, it may be personal preference.
The idea tempts me a lot…even if now it is not easy to find the TC9 at a decent price and,in any case, the hours of printing and post processing are really too much for some serious results... In three years I have not been able to complete 18 so it seems utopian to print another 32 😜. Obviously they would not have the frame around them but I have already designed the system of threaded rods and nuts that holds them together.
Obviously I have not tried all there is. I remember doing this one: https://www.diyaudio.com/community/threads/4-x-5-fr-flat-array.379325/#post-6848676
Not quite ideal, but maybe using groups of 2 drivers instead of 3 might give an acceptably wide beam.
The array in this exercise had the drivers pretty far apart. It was slanted backwards to make the middle two drivers equal distance to a listening position.
Lift up the speaker and you don't need to make in lean backwards.
What I'm trying to say is with a bit of work, there might be simple working solutions for shorter arrays.
Simming takes up less time than printing, maybe worth a shot... It was never a focus for me, that doesn't mean it cannot be done, right?
Not quite ideal, but maybe using groups of 2 drivers instead of 3 might give an acceptably wide beam.
The array in this exercise had the drivers pretty far apart. It was slanted backwards to make the middle two drivers equal distance to a listening position.
Lift up the speaker and you don't need to make in lean backwards.
What I'm trying to say is with a bit of work, there might be simple working solutions for shorter arrays.
Simming takes up less time than printing, maybe worth a shot... It was never a focus for me, that doesn't mean it cannot be done, right?
At listening height and 100 mm above and below it (green traces). Not too bad at all. At 5m listening distance, floor and ceiling set at 6dB absorption.
No side wall reflections!
Compare to a single driver under the same circumstances:
(had to adjust it to the same 5m listening distance)
Which one will sound more clear?
Excuses to the OP for not starting a new thread...
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So we continue, thanks...
I didn't dare use more drivers as 4 parallel groups of 2 drivers in series already creates a pretty low impedance.
One can wire them differently (parallel/series) or pick the 16 ohm TC9. Though I haven't seen any stock of that anywhere.
Source for TC9: https://www.digikey.com/en/products...cCIAL4kAtDBQh0kYft3EylEMj7HTIS5CoAVAMIAnPzGQA
I didn't dare use more drivers as 4 parallel groups of 2 drivers in series already creates a pretty low impedance.
One can wire them differently (parallel/series) or pick the 16 ohm TC9. Though I haven't seen any stock of that anywhere.
Source for TC9: https://www.digikey.com/en/products...cCIAL4kAtDBQh0kYft3EylEMj7HTIS5CoAVAMIAnPzGQA
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A "New Hope" (Star Wars cit.)!
I think after all the energy spent designing, printing and finishing my "mini array", it's worth trying to make them as good as possible.
Nobody forbids me to create a new version, with an even better cabinet, once I have experience and reached a new level of confidence and awareness.
I can only thank your generosity, preparation and passion Ronald! I was not aware of the thread you mentioned, wasted no time and read it. Interesting!
Thanks!
Manuele
Thanks a lot!
I apologize for hogging your thread, but the name you have chosen sounds so good for my situation that it seems only right to write here
Manuele
View attachment 1060475
At listening height and 100 mm above and below it (green traces). Not too bad at all. At 5m listening distance, floor and ceiling set at 6dB absorption.
No side wall reflections!
Compare to a single driver under the same circumstances:
View attachment 1060479
(had to adjust it to the same 5m listening distance)
Which one will sound more clear?
Excuses to the OP for not starting a new thread...
These results look very promising! In this case I could save 2 boxes which can be used as rear speakers for my home theater...
I will run other simulations by changing a few things but still using 9 elements because, at this moment, my amplifier cannot drive such a low impedance speaker and I would like to use the TC9s I have available.
Thanks Ronald for the inspiration!
Manuele