Sica LP110 seems smoother then the LP90... perhaps. For sure I find the Ultraclear shape to look the best. Wavecor T30WA11/12 being ideal imo here in that WG "philosophy."
Have you tried the Harwood, exactly the same than the new Aurum Cantus that is less good than its former iterration said our american fellows?
Wonder if it could be CNC-ed from one block of MDF thick enough ? That would be ideal !
Have you tried the Harwood, exactly the same than the new Aurum Cantus that is less good than its former iterration said our american fellows?
Wonder if it could be CNC-ed from one block of MDF thick enough ? That would be ideal !
Sica LP90 has nice 1.8 Tesla saturated neodymium drive with 94dB sensitivity that style I like as with the Bliesma and Audax tweeters. Nice compact 90mm faceplate with mild waveguide, 28mm coil on alu former that can take something. Wavecor T30WA11/12 is also on top of the list for such kind of speaker. I've chosen the Sica because also together with the Failtal 5PR160 the drivers are both made in Italy as a representation for the many PA driver companies homed there. The Sica tweeter is really on my list of drivers I want to try out. There is a version of the LP90 now with 104mm diameter faceplate (without taking use) and a silver shorting cap (that reduces B to 1.4 Tesla as the gap increases to give space for the shorting cap):
https://rsspeakers.it/wp-content/uploads/2024/08/ZH02800-8.pdf
https://sica.it/wp-content/uploads/2021/02/Z009160.pdf
I like the 94dB original Sica somehow more...
The Ultraclear baffle has pyramid style becaues I do not need an enclosure behind the baffle that must be of cuboid shape as constraint, so I have bit more degree of freedom. I must develop a manufacturing method now to produce such kind of facets with 25° angle on my balcony...
The Harwood AM25 is a relabeled Aurum Cantus AMT tweeter. I have heared this tweeter two times in the last few years, and it's the tweeter with the most fine dynamics and resolution I have ever heared. We had a Scan Illu Berillyum in comparison there, very nice and flawless tweeter, but the Haarwood got the last fine details more correct out. I've heard Mundorf AMTs a few times and never got it, well they were not bad but they never catched me. I've heared that most AMT use the same mylar or kapton foil from Dupont or so but the Aurum Cantus one is from different material. I've also seen measurements of Mundorf tweeters with show kind of comb filter resonance artefacts in the FR, but not the Harwood:
https://www.hifisound.de/out/media/pdf.php?r=Lh4jPASzR5VDXRfW6owkGkumqxy+RXtgoyuP5C3cuaaM/4uTxU/hxNpOZQRHgxWN3zW3BuQcUpyIO0q4hm3y1w==.pdf
https://www.hifisound.de/out/media/pdf.php?r=EHOzCGacW+wZjbFbrE5fE6LcfJuJxQ+XwVEfSCFyUDt4gH25M5/IMVvGmWVlAtzOxWJGAts05Fe5vx/esl6YfQ==.pdf
Well at least this tweeter is today on top of my "like to haves" when the current project with the 4 top speakers and 2 base speakers is done (I fear it will take more than a year from now when I see what all to do and starting to calculate costs), als well as the SB Textreme mid is on top of my today list of most interesting midranges. So why not both putting together? But I have enough to do already with the 4 versions I have fixed for now...
The baffles in CAD model are all 21mm thick, so milling/sawing from one block/sheet of standard wood panel size should be feasible.
https://rsspeakers.it/wp-content/uploads/2024/08/ZH02800-8.pdf
https://sica.it/wp-content/uploads/2021/02/Z009160.pdf
I like the 94dB original Sica somehow more...
The Ultraclear baffle has pyramid style becaues I do not need an enclosure behind the baffle that must be of cuboid shape as constraint, so I have bit more degree of freedom. I must develop a manufacturing method now to produce such kind of facets with 25° angle on my balcony...
The Harwood AM25 is a relabeled Aurum Cantus AMT tweeter. I have heared this tweeter two times in the last few years, and it's the tweeter with the most fine dynamics and resolution I have ever heared. We had a Scan Illu Berillyum in comparison there, very nice and flawless tweeter, but the Haarwood got the last fine details more correct out. I've heard Mundorf AMTs a few times and never got it, well they were not bad but they never catched me. I've heared that most AMT use the same mylar or kapton foil from Dupont or so but the Aurum Cantus one is from different material. I've also seen measurements of Mundorf tweeters with show kind of comb filter resonance artefacts in the FR, but not the Harwood:
https://www.hifisound.de/out/media/pdf.php?r=Lh4jPASzR5VDXRfW6owkGkumqxy+RXtgoyuP5C3cuaaM/4uTxU/hxNpOZQRHgxWN3zW3BuQcUpyIO0q4hm3y1w==.pdf
https://www.hifisound.de/out/media/pdf.php?r=EHOzCGacW+wZjbFbrE5fE6LcfJuJxQ+XwVEfSCFyUDt4gH25M5/IMVvGmWVlAtzOxWJGAts05Fe5vx/esl6YfQ==.pdf
Well at least this tweeter is today on top of my "like to haves" when the current project with the 4 top speakers and 2 base speakers is done (I fear it will take more than a year from now when I see what all to do and starting to calculate costs), als well as the SB Textreme mid is on top of my today list of most interesting midranges. So why not both putting together? But I have enough to do already with the 4 versions I have fixed for now...
The baffles in CAD model are all 21mm thick, so milling/sawing from one block/sheet of standard wood panel size should be feasible.
yup I knew it was the famous relabeled Aurum for Europe. But also heard its last iteration was less linear, so some kits or designs (HTGuides) became not possible with the same filter. Curious to know its lowest cross over point today. Let me know please the day you will measure it with a cap. (to see if the same than 2014 pdf)
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This is the release baseline for DRY, SMOOTH, CLEAR baffle core dimensions and the final platform concept:
(Had to increase the DRY baffle width by 5mm to 175mm, it was too tight and squeezed before)
With two woofer base module sets, each providing 3 presets via Hypex module, 2 x 3 = 6 top speakers is a reasonable capability for the platform until I will come to that state pondering about what to build next again, but this project will surely keep me busy for the next few years...
Still not sure about the exact ULTRACLEAR baffle geometry, this is my current variation space:
Simplified geometry for VituixCAD:
Gives not much difference in simulation result:
Will probably reduce to 31 cm baffle height as the distance to the upper edge and side edges near the tweeter is more different which might behave better in reality, and decide between 23-24cm / 16-17cm width just based on looks...
(Had to increase the DRY baffle width by 5mm to 175mm, it was too tight and squeezed before)
With two woofer base module sets, each providing 3 presets via Hypex module, 2 x 3 = 6 top speakers is a reasonable capability for the platform until I will come to that state pondering about what to build next again, but this project will surely keep me busy for the next few years...
Still not sure about the exact ULTRACLEAR baffle geometry, this is my current variation space:
Simplified geometry for VituixCAD:
Gives not much difference in simulation result:
Will probably reduce to 31 cm baffle height as the distance to the upper edge and side edges near the tweeter is more different which might behave better in reality, and decide between 23-24cm / 16-17cm width just based on looks...
Hello Peter, I have checked numerous forums. The AM 25 is consistant to the new AC2520S, so like the Hobby magasine you linked: a smooth roll off from 4500/5000 hz towards -6 dB at 1900/200. So a 12 db electrical well positionned could permitt a 18 dB acoustical.
Very good for dipole indeed. Sope have complainned a litttle too much THD in its low end and inconcistency (quaility control) with units impossible to use (so folks have to measure their unit as soon as the reception for guaranry).
Cheers.
Very good for dipole indeed. Sope have complainned a litttle too much THD in its low end and inconcistency (quaility control) with units impossible to use (so folks have to measure their unit as soon as the reception for guaranry).
Cheers.
Okay, thanks for this information! Let's discuss in two years or so about the Harwood/Aurum again, until then I might be busy to get the 4 decided top speakers and base systems to a final stage...
Think it's almost done:
Baffle areas:
Think it's almost done:
Baffle areas:
You might consider a "mass loaded quarter wave resonator" (has much less to do with a quarter wave resonator than the name imposes) version to attenuate resonance peaks: https://www.diyaudio.com/community/...rbers-and-port-geometries.388264/post-7695049
I plan this for the vent, like I did with the Edelstoff vent:
Before (blue line):
After:
Requirement is clean bandwidth up to 500Hz LR4 for the base systems, port pipe resonance will be on the lowpass falling slope but might contribute not neglectable to the overall response. But let's see first measurements on the real system, I will decide then to pimp the vent if necessary.
Spare volumes at the back of enclosures are coupled to the overall volume with the breakthroughs sized so that the occurring Helmholz resonance is equal to the standing wave resonance in enclosure height direction. This will help to fight the standing wave and suck it's energy out.
Another option would be to put some pipes of half enclosure internal dimension into the speakers as described in the link from @stv. I did this with my Scandinavian Connections initial setup with 1x 26W Disco in vented tuning (each speaker got two 50mm tubes integrated), but made the experience that the tubes react very sensitive to damping and stuffing to get some effect, and perhaps Helmholz chambers work more robust and effective. I've thrown the pipes out after changing to closed box with the second 26W.
With the standing waves in the enclosure > 600Hz I have to live, but at this frequency damping materials work effectively, so I have many hopes that after proper stuffing the resonances coming from this source are no practical issue.
Before (blue line):
After:
Requirement is clean bandwidth up to 500Hz LR4 for the base systems, port pipe resonance will be on the lowpass falling slope but might contribute not neglectable to the overall response. But let's see first measurements on the real system, I will decide then to pimp the vent if necessary.
Spare volumes at the back of enclosures are coupled to the overall volume with the breakthroughs sized so that the occurring Helmholz resonance is equal to the standing wave resonance in enclosure height direction. This will help to fight the standing wave and suck it's energy out.
Another option would be to put some pipes of half enclosure internal dimension into the speakers as described in the link from @stv. I did this with my Scandinavian Connections initial setup with 1x 26W Disco in vented tuning (each speaker got two 50mm tubes integrated), but made the experience that the tubes react very sensitive to damping and stuffing to get some effect, and perhaps Helmholz chambers work more robust and effective. I've thrown the pipes out after changing to closed box with the second 26W.
With the standing waves in the enclosure > 600Hz I have to live, but at this frequency damping materials work effectively, so I have many hopes that after proper stuffing the resonances coming from this source are no practical issue.
This is where chosing the right position for driver and port along a "qw resonator" can help very much!
There are many design constraints so there is not much space left to find "better" positions. Openings of Helmholz chambers are located near the pressure maximum at the boundary surfaces.
I will try it with proper stuffing first before putting lots of pipes into, I'm looking forward that it's enough to damp the first modes >600Hz on the falling lowpass slope down -8dB or so.
I had thought about to put an additional tube/channel here to realize a Yamaha-like pipe resonator by principle:
I will try it with proper stuffing first before putting lots of pipes into, I'm looking forward that it's enough to damp the first modes >600Hz on the falling lowpass slope down -8dB or so.
I had thought about to put an additional tube/channel here to realize a Yamaha-like pipe resonator by principle:
On which frequency mode will you set up it ? first mode from woofer from the cabinet heigth ? The second bump impedance peak if vented (instead a RLC) ?
What do you mean exactly? The Helmholz resonators are tuned to the first mode along cabinet height.
Hi, you could get rid of first height mode just by putting the woofer(s) acoustic center mid height. Sideways modes don't excite that much either because the drivers are center that dimension already. Lowest modes would now be second of the height, and first from depth of the enclosure. Pressure nodes of all these in the corners of the box of course, so if you put resonators in there you might be able to target them to these.
Due to other design tradeoffs I cannot put the woofers just in the middle height of the enclosure. Most critical is the first half wave mode in height direction (like with many speakers in general), as that frequency is within the passband of the woofer section and such long wavelength is hard to damp. This is why I sized the breakthroughs to the little spare volumes at the enclosure back so that they will give a Helmholz resonator tuned to the first height mode (Hobby Hifi magazine does this very often and has many times proven the sizing and effect). Openings near the top and bottom at the pressure maximum. All other modes are > 600Hz, so just above the target passband of up to 500Hz LR4. Proper stuffing will kill most effect of second height mode and first depth mode then, at least I hope so.
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Looking forward to learning from this thread.
What is the black piece behind the woofer magnets in this cross-section and what's their purpose? Maybe a rubber disc compressed between back of driver and wood rib behind them...maybe to prevent woofer motor from moving backwards?
Interesting use of Hekmholtz resonators inside the box. Where can I learn more/calculation?
If I understood kwesi correctly these are bucking magnets, slightly lowering Qes and increasing efficiency.
In my post linked below I show my experiments and you can find a german website explaining a calculation method: https://www.diyaudio.com/community/...rbers-and-port-geometries.388264/post-7434471
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