Yes, I tried it with original 3D 18IPAL (DS is only 6mm bigger compared to SW) model and just about fits. I wonder how much would cooling be impacted since it's angled and firing directly at aluminum plate.
Plate is only 6mm thick, that is the reason it fits. If 18mm plywood was used it wouldn't.
Regardless of driver choice, I would be happy to test them with 18sw115 and compare it with driver of choice.
Plate is only 6mm thick, that is the reason it fits. If 18mm plywood was used it wouldn't.
Regardless of driver choice, I would be happy to test them with 18sw115 and compare it with driver of choice.
I did some quick sims in hornresp
Inputs;
1 driver 2pi:
2 drivers parallel 2pi:
Max spl 2 drivers parallel 2pi:
Ipal looks to be a clear winner here but might require some eq it seems? Opinions?
Inputs;
1 driver 2pi:
2 drivers parallel 2pi:
Max spl 2 drivers parallel 2pi:
Ipal looks to be a clear winner here but might require some eq it seems? Opinions?
If it was my money I would probably go for the smooth frequency response and proven SW118 speaker. This is based on no experience whatsoever regarding these speakers, but you asked for opinions ;-). I do use the 15DS115-4 and the 21SW152-8 and they are great.
However, if I were to start with a new horn design and I got the results you showed for the Ipal and DS speakers I would not be satisfied, and change things (design, or speaker).
However, if I were to start with a new horn design and I got the results you showed for the Ipal and DS speakers I would not be satisfied, and change things (design, or speaker).
If looking at maximum output graphs ipal seems to get kinda similar shaped graph. Since dsp is available it should be easy fix for flat response and also actually use less power for same output? For all drivers I used 3400W max power for sims and ipal output is quite a bit higher and would also probably have lower power compression since it has better cooling.
It looks like drivers with high Bl figures like to be eq and still keep maximum output. Any experiences with people doing this? More driver displacement around 40-50hz region would be beneficial for cooling
When taken into extremes, ipal transducer TS parameters can be manipulated by using powersoft amplifiers, it's an interesting concept
Just spoke with local distributor for B&C and Powersoft. We buy most components from them so we are also in OEM program. We compared the sims and since nobody really uses similar setup in our country he offered support for testing. Plan is to use 2 2ohm 18ipal powered by Ipalmod (amplifier for ipal) to compare with SW115 running off K20 or 3004PFc4 amplifier. Since Armonia offers good monitoring we should easily compare different drivers. So 2 horns with ipal vs 2 horns with SW115. Plan is to also modify TS parametres for 18IPAL so it behaves flatter, this is possible by using ipalmod.
This should provide some insight into something what is best and if SW115 is far behind ipal. I realize SW115 is better for diy, but would like to contribute something to community with info and measurements not many people have, objective head to head comparsion.
The boxes are now being build slowly by CNC shop, this project is taking longer than expected but I am eagerly looking forward to completing it with good results and some new info for future projects.
I realize this project maybe went a bit off primary goal but since this is diy and we always try to improve already good speakers I think it's worth a try.
Will probably also have chance to compare those boxes with Meyer 1100-LFC and older 700-HP, some kind of ''industry standard''
This should provide some insight into something what is best and if SW115 is far behind ipal. I realize SW115 is better for diy, but would like to contribute something to community with info and measurements not many people have, objective head to head comparsion.
The boxes are now being build slowly by CNC shop, this project is taking longer than expected but I am eagerly looking forward to completing it with good results and some new info for future projects.
I realize this project maybe went a bit off primary goal but since this is diy and we always try to improve already good speakers I think it's worth a try.
Will probably also have chance to compare those boxes with Meyer 1100-LFC and older 700-HP, some kind of ''industry standard''
Direct comparisons are very telling, looking forward to your measurements!
The IPAL, 14.2V RMS, mic at 10m (beyond the mesh domain):
A: 1x18", single configuration.
B: 2x18", horizontal configuration
C: 2x18", half moon configuration
Some colorful images to get an idea how the acoustic impedance is retrieved:
Note: the images are for an older simulation. It is easy to think 'this is great and we can do everything with FEA', but in this case it is only used to get the load on the driver's diaphragm, shown below, and we do nothing with all these nice images, besides printing it and hanging it on the wall 🙂. In this case the ANSYS simulation only takes care of the acoustic part. Without the electric and mechanical part you cannot simulate the complete package. It is ofcourse useful if directivity results are required.
In ANSYS Mechanical the diaphragm is excited by a fixed (complex) velocity and by exporting the average pressure on the diaphragm we can calculate the acoustic impedance. Example of complex pressure on front side of diaphragm:
A: 1x18", single configuration.
B: 2x18", horizontal configuration
C: 2x18", half moon configuration
Some colorful images to get an idea how the acoustic impedance is retrieved:
Note: the images are for an older simulation. It is easy to think 'this is great and we can do everything with FEA', but in this case it is only used to get the load on the driver's diaphragm, shown below, and we do nothing with all these nice images, besides printing it and hanging it on the wall 🙂. In this case the ANSYS simulation only takes care of the acoustic part. Without the electric and mechanical part you cannot simulate the complete package. It is ofcourse useful if directivity results are required.
In ANSYS Mechanical the diaphragm is excited by a fixed (complex) velocity and by exporting the average pressure on the diaphragm we can calculate the acoustic impedance. Example of complex pressure on front side of diaphragm:
Okay so if i get this 10m graph correctly, even if 18ipal response looks worse (we could probably fix that with ipalmod) it is still more sensitive than 18sw115 even at dips (or about the same)?
With using ipamod many TS parameters can be "manipulated''. Not exactly sure which ranges since info is quite limited but i found you can adjust virtually:
Mms
Qes: 0,2 - 0,3
Qts: 0,2 - 0,4
Qms: 5 - 10
Re
Le compensation
Bl
So in theory we could get 18sw115 response with better sensitivity and better control?
With using ipamod many TS parameters can be "manipulated''. Not exactly sure which ranges since info is quite limited but i found you can adjust virtually:
Mms
Qes: 0,2 - 0,3
Qts: 0,2 - 0,4
Qms: 5 - 10
Re
Le compensation
Bl
So in theory we could get 18sw115 response with better sensitivity and better control?
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My gut feeling says the graph shown above cannot predict the real world results, and the only thing to do is try, measure, and see if this "Virtual driver Mode" or "Differential pressure control mode" can improve SPL, quality, control etc. over a 'standard' driver like the SW115.
One of the reasons is that (as shown by Mr. Bennett (B&C) in his interesting Youtube videos) parameters are highly excursion (and temperature) dependent. I do not have experience with running these speakers at nuclear levels for several hours, so I will not guestimate what the result will be. However, it sounds very interesting if I read the PDF of the Ipalmod! 🙂
One of the reasons is that (as shown by Mr. Bennett (B&C) in his interesting Youtube videos) parameters are highly excursion (and temperature) dependent. I do not have experience with running these speakers at nuclear levels for several hours, so I will not guestimate what the result will be. However, it sounds very interesting if I read the PDF of the Ipalmod! 🙂
Did some sims in hornresp using slightly modified 18ipal TS parameters
Raised Qes to 0.2 and raised Qms to 5, this causes Bl to drop to about 20,5.
this is only to see what happens, other parameters might be even more optimal
Here are results 18sw115 left 18ipal right
1cab:
4 cabs:
Impedance curve(really close to original danley?):
Maximum spl 4 cabs:
Really close, I suppose 18ipal has slight edge here in real life since probably it has better cooling and better limiters
Raised Qes to 0.2 and raised Qms to 5, this causes Bl to drop to about 20,5.
this is only to see what happens, other parameters might be even more optimal
Here are results 18sw115 left 18ipal right
1cab:
4 cabs:
Impedance curve(really close to original danley?):
Maximum spl 4 cabs:
Really close, I suppose 18ipal has slight edge here in real life since probably it has better cooling and better limiters
Have you finished construction of any of those boxes?
Well actually I had to find another CNC shop since first one was too busy. In Slovenia it's relatively hard to find CNC shops that will do such small jobs. Anyways this week we found one and they already recieved all plywood so they are cutting it rn. Project was not taking any meaningful progress in meantime so I did not post any major updates here.
Here are some pictures of final model
Position of pressure sensor:
A bit updated bracing:
I hope build will be complete till the end of the year. As said we will test 2 boxes with ipal and 2 boxes with 18SW115 8ohm. I could borrow some original cabinets from local companies. Main brands are Meyer and d&b.
We already did some quick tests with d&b V sub and my tapped horns (similar to Xoc1 design). 2:1 ratio they had quite similar sensitivity and TH went a bit lower in measurements and about 1db more in 40Hz range, above 60 almost identical. Before testing I tought 2 Vsub would be louder at 60Hz and up and about same level at lower frequencies. For testing purposes we also connected Vsub to non-d&b branded amp - so run without presets to see raw response of box without processing - I think this is realistic to compare overall box design. All listening tests were done with correct amp preset for Vsub and just crossovers for TH. Subjective opinion was V sub felt a bit more punchy and TH deeper sound. Did not do any max spl tests but regarding sensitivity I believe max spl would be close 1 TH: 2 Vsub for short term (depends on frequency), long term I think tapped horn would do better since it has better cooling compared to BR. BR box appears subjectively louder, probably because it has a bit more punch, but when TH level is increased it feels more natural and effortless, really clean LF and more consistent in my opinion. Also 2 Vsubs are a bit bigger than TH. I felt I had to turn TH up a bit more to get them to same subjective level with my tops (probably since they have less punch and clean lf). When turned up entire system low end from TH was massive (played different genres - from DnB to techno, house, commercial...) Suppose I could also compare these BC18 cabs to my tapped horns for start.
In my opinion I would prefer TH any day over 2 Vsub, some people might not agree tho - I noticed that even when presented with objective measurements some might argue that some well known manufacturer box still preforms way better - probably because of brand recognition and price tag they paid for it. I think this sub design (BC18) should really take things to the next level and can't wait to test them.
Happy to do more detailed measurements that give more objective info, but I am not sure what should I measure and how, as till now we did most tests to get subjective opinion. We only objectively measured raw response - to see which box gets louder with same input Voltage and frequency response (SMAART with transfer function) I do not really care about some max peak spl with some specific signal but I want to see how would box preform in real word with music and still sound good, I think those tests are better compared to manufacturer listing some peak spl values that might not be even achievable in real word scenario, since we use speakers to reproduce music with complex signal. We have Powersoft amps with good monitoring of power and voltage I suppose this makes our situation easier.
Open to suggestions how we should evaluate design with objective information and stay realistic so it gives us transparent info.
Here are some pictures of final model
Position of pressure sensor:
A bit updated bracing:
I hope build will be complete till the end of the year. As said we will test 2 boxes with ipal and 2 boxes with 18SW115 8ohm. I could borrow some original cabinets from local companies. Main brands are Meyer and d&b.
We already did some quick tests with d&b V sub and my tapped horns (similar to Xoc1 design). 2:1 ratio they had quite similar sensitivity and TH went a bit lower in measurements and about 1db more in 40Hz range, above 60 almost identical. Before testing I tought 2 Vsub would be louder at 60Hz and up and about same level at lower frequencies. For testing purposes we also connected Vsub to non-d&b branded amp - so run without presets to see raw response of box without processing - I think this is realistic to compare overall box design. All listening tests were done with correct amp preset for Vsub and just crossovers for TH. Subjective opinion was V sub felt a bit more punchy and TH deeper sound. Did not do any max spl tests but regarding sensitivity I believe max spl would be close 1 TH: 2 Vsub for short term (depends on frequency), long term I think tapped horn would do better since it has better cooling compared to BR. BR box appears subjectively louder, probably because it has a bit more punch, but when TH level is increased it feels more natural and effortless, really clean LF and more consistent in my opinion. Also 2 Vsubs are a bit bigger than TH. I felt I had to turn TH up a bit more to get them to same subjective level with my tops (probably since they have less punch and clean lf). When turned up entire system low end from TH was massive (played different genres - from DnB to techno, house, commercial...) Suppose I could also compare these BC18 cabs to my tapped horns for start.
In my opinion I would prefer TH any day over 2 Vsub, some people might not agree tho - I noticed that even when presented with objective measurements some might argue that some well known manufacturer box still preforms way better - probably because of brand recognition and price tag they paid for it. I think this sub design (BC18) should really take things to the next level and can't wait to test them.
Happy to do more detailed measurements that give more objective info, but I am not sure what should I measure and how, as till now we did most tests to get subjective opinion. We only objectively measured raw response - to see which box gets louder with same input Voltage and frequency response (SMAART with transfer function) I do not really care about some max peak spl with some specific signal but I want to see how would box preform in real word with music and still sound good, I think those tests are better compared to manufacturer listing some peak spl values that might not be even achievable in real word scenario, since we use speakers to reproduce music with complex signal. We have Powersoft amps with good monitoring of power and voltage I suppose this makes our situation easier.
Open to suggestions how we should evaluate design with objective information and stay realistic so it gives us transparent info.
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The d&b V-Sub is a cardioid design, it would be interesting to compare its polar response to the TH.
I've found that TH have more directivity than similar sized BR and FLH, but didn't have a large enough free-field area to get clean results.
The CEA2010 burst test like Josh Ricci performs would also make for a good comparison:
https://data-bass.com/articles/5cc0bc36a75a260004255c88#a8818f1098c631a55c361b06d9fad10f
REW has the burst test tones included in the noise generator.
Thank you for suggestion @weltersys . Those are the test that seem to reflect real world preformance most realistically.
Also some updates, finally making progress:
Will post more pictures soon 🙂 trying to document entire build well, so anyone could build it. Also will post my detailed 3d model and my dxf files for CNC, just want to wait a bit to see for sure if they are without any mistakes.
Also some updates, finally making progress:
Will post more pictures soon 🙂 trying to document entire build well, so anyone could build it. Also will post my detailed 3d model and my dxf files for CNC, just want to wait a bit to see for sure if they are without any mistakes.