They definitely can play higher, I believe they should match original BC218 quite closely. Rolling off around 60Hz provides proper acoustical slope and crossover frequency to match tops - they should hit about -6db at 80Hz. This is how I like to set my system. Time alignment with tops is crucial to keep nice and tight kick - EQ or crossover won't help if anything is out of phase 🙂 BTW what exactly is a resaon for 150Hz crossover?
I will measure group delay, distortion and sensitivity outdoor when weather gets warmer.
Original graphs were done with 1/6 oct smoothing, coherence is good
i bet it will sound EFFINN INCREDIBLE!!!
hey, did you put a rubber mat below the subs so they do not "walk" under heavy SPL's
or rubber feet ?
hey, did you put a rubber mat below the subs so they do not "walk" under heavy SPL's
or rubber feet ?
We put some rubber mats under tapped horns, BC118 have rubber feet and are quite ''grippy" so no issues 🙂
Ahhh yea awsome outcome even for first prototype revision.
I was asking how high it can play because I usually if the phase alows it like to play my subs high if the distortion values are good and they should with a fully enclosed subwoofer like these letting them do a large part of the kick also. My tops depending on the setup are crossovered at 90 with a big setup where low mid horns are combined and 120 otherwise. And with 120 if possible I like to have a wider crossover playing my tops old JBL HLA series down to 120 and subs up to 130-140 if they work nice with the phase.
And because the tops are 3 ways I like to use the subwoofers both as Sub and kick if possible to avoid the need for extra crossovers.
Atm using old JBL Wbins work good but ofcause sub wise no comparison to soemthing like that !
But it's ofcause also taste and depends on speakers how phase compliment they are with each other and especially how well they behave in the time domain.
I hope soon I will have some resources to try my luck at any of the Boundary compliment type subwoofers !
BTW @All_1 I would maybe be interested in AKABAK validation of the design potentially.
For me that would be a quite interesting exercise if you got any interest in it but it would require you to take some good measurements.
Maybe we could learn a little from it and I could provide you a full simulation in AKABAK (I will have to practice a bit but anyways wanted to do that) and if you like to do any modifications to your plan I can run it through.
Although I would also need the 3D model so if you would be hesitant to share that I would understand that but for me it would be rly nice to learn how AKABAK would model the boundary effects and what works and what does not. I would obviously not share your plans or build them without any previous agreement Especially because its a copy of a commercial product of Tom Danley.
AKABAK has some example presentations regarding design validation which i wanted to basically recreate with this design.
https://www.randteam.de/AKABAK3/AKABAK-Studies.html
https://www.randteam.de/_Docs/AKABAK/Studies/AKABAK - Project ABEC21 Sealed 3.pdf
https://www.randteam.de/Publications/Pub_Acoustics2012_BEM_LEM_Coupling.html
You can think about it and let me know I wont be available directly but I will try to make myself some time 🙂
For me that would be a quite interesting exercise if you got any interest in it but it would require you to take some good measurements.
Maybe we could learn a little from it and I could provide you a full simulation in AKABAK (I will have to practice a bit but anyways wanted to do that) and if you like to do any modifications to your plan I can run it through.
Although I would also need the 3D model so if you would be hesitant to share that I would understand that but for me it would be rly nice to learn how AKABAK would model the boundary effects and what works and what does not. I would obviously not share your plans or build them without any previous agreement Especially because its a copy of a commercial product of Tom Danley.
AKABAK has some example presentations regarding design validation which i wanted to basically recreate with this design.
https://www.randteam.de/AKABAK3/AKABAK-Studies.html
https://www.randteam.de/_Docs/AKABAK/Studies/AKABAK - Project ABEC21 Sealed 3.pdf
https://www.randteam.de/Publications/Pub_Acoustics2012_BEM_LEM_Coupling.html
You can think about it and let me know I wont be available directly but I will try to make myself some time 🙂
I can post 3d model here, it is not an issue. Currently very busy with modifying some 2x18 ported subs for our local rental company before summer season but will find some time to make 360degree measurements of BC118. WIll post my version .stp here when I get home in the afternoon. It was meant to be some sort of open DIY project from the start so all information will be provided to public 🙂
Regarding running them with crossover higher it is definitely possible, they sound responsive but will probably require some eq and careful crossover/delay settings to match well with the tops. They kick as you would expect FLH to kick, I hope that was somehow informative 😉
Regarding running them with crossover higher it is definitely possible, they sound responsive but will probably require some eq and careful crossover/delay settings to match well with the tops. They kick as you would expect FLH to kick, I hope that was somehow informative 😉
Ahhh that would be awesome 😀
And no stress with it at some point when ya can share the 3D model I could already start importing it into AKABAK and make a simulation also for different setups.
And when ya at some point find some time to do some measurements probably interesting places would be inside the rear chamber, At the start of the horn, End of the horn before the port and 1 m away so that we can than validate how accurate the AKABAK model would be or if anything funky is going on.
And also thanks for the info I Am quite curious probably could even optimize them a bit more when playing them high for a better response.
Good luck with you ported sub project also!
Cheers
And no stress with it at some point when ya can share the 3D model I could already start importing it into AKABAK and make a simulation also for different setups.
And when ya at some point find some time to do some measurements probably interesting places would be inside the rear chamber, At the start of the horn, End of the horn before the port and 1 m away so that we can than validate how accurate the AKABAK model would be or if anything funky is going on.
And also thanks for the info I Am quite curious probably could even optimize them a bit more when playing them high for a better response.
Good luck with you ported sub project also!
Cheers
2x18 are just slightly modified meyer hp700, nothing special really. We kept original electronics and just mounted some suitable B&C drivers in them and made ports a bit bigger. We were also doing a bit of testing by mounting 2 18NTLW5000 drivers in them and power both with external amp and compare them to our 18NTLW5000 tapped horn. Frequency response was almost identical, 2x18 had about 2-3db dB more SPL across entire range (It is a bit bigger box and 2x power). Tapped horn had considerably lower distortion (especially around tuning), behaved more consistently comparing low and high levels, had wayy less air noise and felt like is moving more air but did not sound as fast/responsive as BR, but sounded ''deeper'' - but difference was very minimal and could be noticed only at side by side comparison. For now tapped horns suit us better and I see no reason why somebody would go 2x18 route. Maybe for sheer power density but event that might be debatable since in TH driver gets better cooling
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Alright, I now created a rly basic copy of the HornResp LEM into the Akabak LEM First.
I was planning to maybe consider 2 horns simultaneously and consider the last Horn expansion as a combined horn.
Atm I only use the 4 horn elements Hornresp considers but I was planning to make it more detailed and also considering the folds... I think I probably will end up with twice the amount of horn elements i imagine.
But I am not sure if I somehow missed it but I cant find anywhere the width of the cabinet only the height and depth. If I know that I can share the outcome of the first simulation run.
Altho if we already got also the 3D model I might wait and throw it just directly into the Boundary Element model.
Because no matter how we wont capture the complexity of the horn with the LEM model alone more a for fun kinda thing on my side I guess.
I would just need 1 quarter I can than just mirror it inside Akabak to safe on computing and was planning to simulate at least 2 or 4 elements because I guess that's rly interesting and I honestly would have no clue how to properly simulate otherwise the throat exit due to it being weirdly shaped.
I am 100% sure I will soon run into some issues where I need some help with Akabak but lets see would be great if here would be someone who can later check it and could solve some smaller issues of my simulation.
I was planning to maybe consider 2 horns simultaneously and consider the last Horn expansion as a combined horn.
Atm I only use the 4 horn elements Hornresp considers but I was planning to make it more detailed and also considering the folds... I think I probably will end up with twice the amount of horn elements i imagine.
But I am not sure if I somehow missed it but I cant find anywhere the width of the cabinet only the height and depth. If I know that I can share the outcome of the first simulation run.
Altho if we already got also the 3D model I might wait and throw it just directly into the Boundary Element model.
Because no matter how we wont capture the complexity of the horn with the LEM model alone more a for fun kinda thing on my side I guess.
I would just need 1 quarter I can than just mirror it inside Akabak to safe on computing and was planning to simulate at least 2 or 4 elements because I guess that's rly interesting and I honestly would have no clue how to properly simulate otherwise the throat exit due to it being weirdly shaped.
I am 100% sure I will soon run into some issues where I need some help with Akabak but lets see would be great if here would be someone who can later check it and could solve some smaller issues of my simulation.
I did some research and found out that patent US6411718B1 expired on December 8, 2018
, so your design is not a unity but a synergy ?
https://patents.google.com/patent/US6411718B1/en?oq=US6411718B1
then he made a refinement to the unity horn with patent US8284976B2 called the Enhanced Horn
i think called now SYNERGY HORN the table below shows key points between the 2
i guess all DSL SH series are Synergies and are protected till 2029
- (US6411718B1): Since it expired, you can replicate the exact design—conical horn, multiple drivers at specific points.
- (US8284976B2) Features: can’t copy its specific enhancements (e.g., manifold coupling, tuned ports) without risking infringement until 2029. However stick to US6411718B1’s basics and avoids US8284976B2’s claims and we OK!!.
BTW US8457341B2 the TH patent will expire 2030
Ok awsome thank you !
I am impressed by the details it's very well made.
I will simplify it and prepare it for AKABAK and share it here when I find time !
It is smaller in dimension, cheaper, and probably has quite similar output above 1200Hz where I need it. 464 would not fit into cabinet if I remember correctly. Did not test 464 at all, but maybe will in near future
lol, i tough the file was corrupted cause fusion and freecad took around 1 minute on my PC to open....
then i realized that the file is so detailed that my PC struggle to calculate all of it then spit it out on the screen!
Hey tiny update.
Here both the Simplified STEP and Mesh file for AKABAK. I took way too long removing every god damn screw hole by hand because I suck at fusion haha
This is the second iteration after having a more complex one before but that ran forever and gave some issues.
I removed all bracing except the 3 at the front because they will have some influence I think when simulating higher frequency range but we could test that.
The interface added is 50mm in front of the exit (if someone is experienced with AKABAK I don't know whats the best rules for adding the interface if its a specific distance... also because of the subs special behavior regarding the boundary compliance)
Pls feel free to use it and ideally even improve it in fusion there are some small errors with the model not nicely aligning and i could most likely remove even more edges... Also for the meshing there can be probably optimizations for accuracy vs performance.
I already got a AKABAK project but I have not yet updated this updated model due to lack of time still having a old broken inside.
As soon as I find time I will be happy to share it because I probably also need some help.
What would be very helpful is if someone could dissect the folded horn in its individual parts for the LEM model to make that bit more detailed than the HornResp. Altho I assume I will have to over estimate the horn length a tiny bit for a BC type horn? Or not?
If I fcked up in any way lemme know happy for any feedback.
Here both the Simplified STEP and Mesh file for AKABAK. I took way too long removing every god damn screw hole by hand because I suck at fusion haha
This is the second iteration after having a more complex one before but that ran forever and gave some issues.
I removed all bracing except the 3 at the front because they will have some influence I think when simulating higher frequency range but we could test that.
The interface added is 50mm in front of the exit (if someone is experienced with AKABAK I don't know whats the best rules for adding the interface if its a specific distance... also because of the subs special behavior regarding the boundary compliance)
Pls feel free to use it and ideally even improve it in fusion there are some small errors with the model not nicely aligning and i could most likely remove even more edges... Also for the meshing there can be probably optimizations for accuracy vs performance.
I already got a AKABAK project but I have not yet updated this updated model due to lack of time still having a old broken inside.
As soon as I find time I will be happy to share it because I probably also need some help.
What would be very helpful is if someone could dissect the folded horn in its individual parts for the LEM model to make that bit more detailed than the HornResp. Altho I assume I will have to over estimate the horn length a tiny bit for a BC type horn? Or not?
If I fcked up in any way lemme know happy for any feedback.