So quick background. I am a mobile dj who is an experienced woodworker.
I have built numerous PA cabinets over the years along with some car audio subwoofers in the past.
I was just about to start building 2 Titan 48s from BFM (3015LF) when I ran across the SS15 from JBELL.
I am intrigued and want to consider building 2 of these but I can not find the current plans that incorporate the latest design. (I have the original plans without the cone correction) I read the entire thread that Robin N Zone started but it sorta died at the end.
https://www.diyaudio.com/forums/subwoofers/232784-pa-subdesign-eminence-kappalite-3015lf.html
And I looked for the plans in the JBELL's original post https://www.diyaudio.com/forums/subwoofers/170771-single-sheet-th-challenge.html (post #s 1499, 1503, 1564, etc) but its not very clear.
I downloaded the Excel file provided by Brian Steele https://www.diyaudio.com/forums/subwoofers/171747-spreadsheet-folded-horn-layouts.html on his website but it has Visual Basic errors. Also I have no experience with HORNRESP.
I feel I am down the "rabbit hole". I own the T48 plans already and the 2 x 3015LFs and have a Crown XTi so I am fairly eager to get this project started.
I have built numerous PA cabinets over the years along with some car audio subwoofers in the past.
I was just about to start building 2 Titan 48s from BFM (3015LF) when I ran across the SS15 from JBELL.
I am intrigued and want to consider building 2 of these but I can not find the current plans that incorporate the latest design. (I have the original plans without the cone correction) I read the entire thread that Robin N Zone started but it sorta died at the end.
https://www.diyaudio.com/forums/subwoofers/232784-pa-subdesign-eminence-kappalite-3015lf.html
And I looked for the plans in the JBELL's original post https://www.diyaudio.com/forums/subwoofers/170771-single-sheet-th-challenge.html (post #s 1499, 1503, 1564, etc) but its not very clear.
I downloaded the Excel file provided by Brian Steele https://www.diyaudio.com/forums/subwoofers/171747-spreadsheet-folded-horn-layouts.html on his website but it has Visual Basic errors. Also I have no experience with HORNRESP.
I feel I am down the "rabbit hole". I own the T48 plans already and the 2 x 3015LFs and have a Crown XTi so I am fairly eager to get this project started.
Check the link below, there are two different TH-SS styles to use, with and without cone correction. The model was made with easy integration with hornresp and there are video tutorials that will help you. For instance, the model has an internal spreadsheet that you can just copy and paste data to hornresp for easy simulation. In addition, you can adjust the model to better fits your driver. When I built mine it was needed to increase horn length to reach 40Hz and to reduce compression ratio. In summary, you can copy any plan or customize it using the FreeCAD model.
Anyone can use that model, everything is basically double click, edit the quote and apply the model and outputs will selfupdate for you.
https://freeloudspeakerplan.rf.gd
I don't remember all advantages, but one is to improve the higher frequencies. It also shift a little the shape of the SPL curve once you are changing S2, and depending the way you introduced it you can change S1 too, all that allow more freedom to tune the design and improve frequency response. If I'm not mistaken it helps to reduced cone excursion too.
You can check it on Hornresp, try to let all input parameter fixed and only change S1 and S2,
The tuning needs to be done according to the driver you are planning to use because changing S2 will change compression ratio, all the gains mentioned above will generate as side effect: higher load in the cone witch will lead to more distortions, audible or not, and it will increase cone fatigue leading to reduced life.
There is no general rule that will make one feature always better in all cases.
You can check it on Hornresp, try to let all input parameter fixed and only change S1 and S2,
The tuning needs to be done according to the driver you are planning to use because changing S2 will change compression ratio, all the gains mentioned above will generate as side effect: higher load in the cone witch will lead to more distortions, audible or not, and it will increase cone fatigue leading to reduced life.
There is no general rule that will make one feature always better in all cases.
ic, speaking of what the OP was looking for
i am still amazed by Mr. Bell S15, so digging in to this forum i found this thread
that did not had much noise but looks like the mods to the original SS15 thanks to the help of XOC1
did result in a great result.
the OP of that thread was NZONE and he actually build the cabinets according to his published plan and cut sheet
i will post the thread over here for reference
https://www.diyaudio.com/community/...r-the-eminence-kappalite-3015lf.232784/page-5
with the above HR input screen i simmed a PRV 15SW2000 with better results than the 3015LF
at least that is what HR says
, only thing is that NZONE used 12mm ply for the cut sheet, and metric system
i think i will use 18mm for my build.
i need to find someone who have cad skills so to convert from mm to inches
as a buddy who will help me to cut the wood do not like/work with metric.
PRV 15SW2000
NZONE XOC1 mod JBell SS15
3015LF have 9.6 xmax 17BL 3" voice coil 450w AES
15SW2000 have 12.5 xmax 23.2BL 4" split voice coil 1Kw AES
@900 watts
12.5 xmax
4 cabs
i am still amazed by Mr. Bell S15, so digging in to this forum i found this thread
that did not had much noise but looks like the mods to the original SS15 thanks to the help of XOC1
did result in a great result.
the OP of that thread was NZONE and he actually build the cabinets according to his published plan and cut sheet
i will post the thread over here for reference
https://www.diyaudio.com/community/...r-the-eminence-kappalite-3015lf.232784/page-5
with the above HR input screen i simmed a PRV 15SW2000 with better results than the 3015LF
at least that is what HR says
, only thing is that NZONE used 12mm ply for the cut sheet, and metric system
i think i will use 18mm for my build.
i need to find someone who have cad skills so to convert from mm to inches
as a buddy who will help me to cut the wood do not like/work with metric.
PRV 15SW2000
NZONE XOC1 mod JBell SS15
3015LF have 9.6 xmax 17BL 3" voice coil 450w AES
15SW2000 have 12.5 xmax 23.2BL 4" split voice coil 1Kw AES
@900 watts
12.5 xmax
4 cabs
I also build TH SS15 with modified dimensions to better work with my driver.
There was a thread as you can see below, but unfortunately the images were loaded into another website that are no longer available :/
https://www.diyaudio.com/community/threads/th-15-flat-response-to-35hz-3db-by-lordsansui.299036/
Attached you can see some details from the build, simulation vs measurements, benchmark vs SS15 Jbell and THAM15, cone correction and other.
My Mod has 293L
SS15 Jbell 230L
THAM 187L
There was a thread as you can see below, but unfortunately the images were loaded into another website that are no longer available :/
https://www.diyaudio.com/community/threads/th-15-flat-response-to-35hz-3db-by-lordsansui.299036/
Attached you can see some details from the build, simulation vs measurements, benchmark vs SS15 Jbell and THAM15, cone correction and other.
My Mod has 293L
SS15 Jbell 230L
THAM 187L
Attachments
I remember to see those pics in the long SS15 threads do you still have the plans for your SS15-B?
None of the pics on your thread show , this forum can host pics now
no more external free hosters , the NZONE version that XOC1 helped or did almost all, use the same single sheet but was tweaked a bit inside so the Fs shifted to hit lower , with the Brazilian driver it hits 40 clean , in groups of 4 looks better , no EQ You need (insert Yoda voice here) 😂
So I stick with this one or try yours ?
I know is bigger, how many sheets of ply? 1 1/2?
None of the pics on your thread show , this forum can host pics now
no more external free hosters , the NZONE version that XOC1 helped or did almost all, use the same single sheet but was tweaked a bit inside so the Fs shifted to hit lower , with the Brazilian driver it hits 40 clean , in groups of 4 looks better , no EQ You need (insert Yoda voice here) 😂So I stick with this one or try yours ?
I know is bigger, how many sheets of ply? 1 1/2?
Adjust the design is very simple and now automatic, each driver behavior differently, there are some that works better with higher compression ratio, other with low compression ratio. Internal and external expansion angles can be adjusted also and will affect the result, I made more then 60 simulations to find the best option for me and even so at maximum power the driver exceed Xmax but not Xmech, but my amplifier will not delivery max power so I'm ok with that.
You can create a matrix in a excel sheet, slowly you change the design and plot the response, overlay the responses and then you will see the changes that improve the response and the other that don't, in this way you can converge to a better result.
I'm the automation level available today in Freedcad, all the simulations that took me a lot of days could be done in less then 1h.
The most important point is to choose a design, pic one bro, you need to leave this phase behind.
Today I like more the Paraflex C and Manifold, both can deliver better response considering the same volume and they are easier to build, etc.
You can create a matrix in a excel sheet, slowly you change the design and plot the response, overlay the responses and then you will see the changes that improve the response and the other that don't, in this way you can converge to a better result.
I'm the automation level available today in Freedcad, all the simulations that took me a lot of days could be done in less then 1h.
The most important point is to choose a design, pic one bro, you need to leave this phase behind.
Today I like more the Paraflex C and Manifold, both can deliver better response considering the same volume and they are easier to build, etc.
If I understand correctly , you mean that a paraflexC of the same volume of in this case the NZONE mod SS15 will give better freq response , you saw that in the sims or you actually built the cabs and measured them ?
Yes the C type is way easier but that's why my mind crash , how a simpler fold scheme can get better results? So we use to overcomplicate things?
Yes the C type is way easier but that's why my mind crash , how a simpler fold scheme can get better results? So we use to overcomplicate things?
Didn't measure it but many people build them and measure, so comparison is easy to make.
The point is the way the box work, they will load the driver differently and so producing different SPL curve.
Check the link below the post # 1 attachment #1, OPT 1 = Paraflex C and OPT 2 = Manifold, manifold gives even wider bandwidth
https://www.diyaudio.com/community/...nifold-mtb-be-better-than-tapped-horn.391782/
Check also post #18.
The point is the way the box work, they will load the driver differently and so producing different SPL curve.
Check the link below the post # 1 attachment #1, OPT 1 = Paraflex C and OPT 2 = Manifold, manifold gives even wider bandwidth
https://www.diyaudio.com/community/...nifold-mtb-be-better-than-tapped-horn.391782/
Check also post #18.
I only built THSS-1
The THSS-2 with integrated cone correction was improved later in terms of model because the way to simulate based on wath is available from HR, so it's not fully modeled but good approximation.
This refer to Paraflex-C and Manifold.
The THSS-2 with integrated cone correction was improved later in terms of model because the way to simulate based on wath is available from HR, so it's not fully modeled but good approximation.
This refer to Paraflex-C and Manifold.