Hey guys call me Dr. Frankenstein for bringing this back to life, but I just read all 42 pages on this Tham 15. Awesome Job Martinsson! I have already built Art's amazing Keystone sub and now need a sub for the old boat. This design seems to fit the bill as its compact and performs. I love reading on this forum its very humbling to sit in the peanut gallery and listen to you audiophile mad scientists work things out (coming from a lowly mechanical engineer who has a love affair with Solidworks and FEA as well).
Anywho nuff brown nosing. This sub is going in the back corner of the ole boat. I have a Kicker CX1200.1 (600watts rms at 4ohms). As you know I am power limited on a boat. I also am a full on bass head sorry its a real condition. Here are my questions:
1. Is there a consensus on the reflectors... I mean real world testing results Mk 1, 2, 3, 4. from Martinssons blog it looks like no reflectors is the way to go overall. Martinsson's Blog - Showdown in Stenungsund (THAM 15 & MKII proposal)
2. I hate being the "what about my driver guy", but I'm chained to an alternator so to speak. The CX1200.1 is capable of 1200watts rms at 2ohms. I plan on buying the recomended B&C B&C 15TBX100 15 4ohm sub. I like to follow builds with real world results. That and my B&C 18SW115 18 is indestructibleish! Are there any 2ohm 15" subwoofers that you would recommend instead to save some load on the electrical system? Or for that matter is there a reason to pick a different subwoofer like the dayton Pa385 s (I'm going for maximum spl and dont care if its a $400 driver). I just worked the entire month of May, everyday at a refinery turnaround and need retail therapy.
3. Do any of the solidworks people still follow this page and have a cut sheet or would send me their model? Otherwise I will try to give back and model this whole thing and create a cut sheet to share. It would be great if this forum had a "library". Art did a good job of summarizing all 150pages on the first page. It crossed my mind wedging another Keystone in the back corner of the 19 foot bayliner haha.
4. As for filters it looks like 36hz 24db oct and 140hz. Anyone who has built one of these want to chime in on any other tips or warnings?
5. I listen to low crestfactor EDM mostly, has anyone pushed this sub using 1000 watts rms yet? I'm assuming you would need to adjust the lpf to avoid excursion issues. If not I will push it till it breaks and let you know.
Thanks for the help. I love math, but deal with the gap between simulation and the real world every day.
Anywho nuff brown nosing. This sub is going in the back corner of the ole boat. I have a Kicker CX1200.1 (600watts rms at 4ohms). As you know I am power limited on a boat. I also am a full on bass head sorry its a real condition. Here are my questions:
1. Is there a consensus on the reflectors... I mean real world testing results Mk 1, 2, 3, 4. from Martinssons blog it looks like no reflectors is the way to go overall. Martinsson's Blog - Showdown in Stenungsund (THAM 15 & MKII proposal)
2. I hate being the "what about my driver guy", but I'm chained to an alternator so to speak. The CX1200.1 is capable of 1200watts rms at 2ohms. I plan on buying the recomended B&C B&C 15TBX100 15 4ohm sub. I like to follow builds with real world results. That and my B&C 18SW115 18 is indestructibleish! Are there any 2ohm 15" subwoofers that you would recommend instead to save some load on the electrical system? Or for that matter is there a reason to pick a different subwoofer like the dayton Pa385 s (I'm going for maximum spl and dont care if its a $400 driver). I just worked the entire month of May, everyday at a refinery turnaround and need retail therapy.
3. Do any of the solidworks people still follow this page and have a cut sheet or would send me their model? Otherwise I will try to give back and model this whole thing and create a cut sheet to share. It would be great if this forum had a "library". Art did a good job of summarizing all 150pages on the first page. It crossed my mind wedging another Keystone in the back corner of the 19 foot bayliner haha.
4. As for filters it looks like 36hz 24db oct and 140hz. Anyone who has built one of these want to chime in on any other tips or warnings?
5. I listen to low crestfactor EDM mostly, has anyone pushed this sub using 1000 watts rms yet? I'm assuming you would need to adjust the lpf to avoid excursion issues. If not I will push it till it breaks and let you know.
Thanks for the help. I love math, but deal with the gap between simulation and the real world every day.
the than will never reach 35hz. 40hz +/- is max. 140hz is possible but sounds hollow in that frequency range, and got bit of dip, possible the large dip can be modified somewhat with cone compensation or little bit of stuffing g at the start of horn. as with all designs put driver specs in hornresp to see if it suitable for tham. so you don't need to push it till breaks and Sim the maximum the driver can handle in tham. you need a really good driver to push it 1000w.
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I did this late at night after work as fast as I could so its not great, but it conveys the design and shows both Metric and Imperial units. I also did a fractions drawing for us Americans haha. Its unchecked and I will build from it this weekend and let you know if there are any issues. It includes dual units for checking against Martinssons design and a cut sheet. I will let you know how the 15TBX100 15 4ohm sub build turns out.
I will add the pdf's later but here is the link to the google drive:
https://drive.google.com/open?id=0B7r20kCTj4fWS0lqajd4WmR4bUU
I will add the pdf's later but here is the link to the google drive:
https://drive.google.com/open?id=0B7r20kCTj4fWS0lqajd4WmR4bUU
Look for some help. I'm trying to buy drivers for 2 tham 15's on a budget.
-18sound 15lw2400 $370 for the pair (used)
-18sound 15LW1401 $340 for the pair (used)
-The box 15lb100 $290 for the pair
Obviously the 18sound drivers are higher quality and an take more power, but these drivers sim damn near identical in hornresp (hard to even see the grey vs black line). Are there 'real world' qualities the 18sound drivers have over the cheap thomann drivers (ie sound quality/clarity?) Is it worth the extra $30 for the 15lw2400s' extra power (2400 watts program vs 1400 watts program) if the drivers will never be able to take more than 1000 watts anyway because of the box design?
Based on simulation alone I'd say to go with the cheapest option, but I'm sure theres more to it?
Thanks!
-18sound 15lw2400 $370 for the pair (used)
-18sound 15LW1401 $340 for the pair (used)
-The box 15lb100 $290 for the pair
Obviously the 18sound drivers are higher quality and an take more power, but these drivers sim damn near identical in hornresp (hard to even see the grey vs black line). Are there 'real world' qualities the 18sound drivers have over the cheap thomann drivers (ie sound quality/clarity?) Is it worth the extra $30 for the 15lw2400s' extra power (2400 watts program vs 1400 watts program) if the drivers will never be able to take more than 1000 watts anyway because of the box design?
Based on simulation alone I'd say to go with the cheapest option, but I'm sure theres more to it?
Thanks!
The 18 sound 15lw2400 has an xmax of 10mm and low thermal compression
The Thomann 15 has an xmax of about 5.5mm
So the 18 sound will shift nearly double the air with low distortion.
The 18 sound will also do 38mm max peak to peak excursion so will handle transients that would kill the Thomann - which is probably made by Elder Audio in China
The Theomann is quite a respectable budget driver - But it is a budget driver!
The Thomann 15 has an xmax of about 5.5mm
So the 18 sound will shift nearly double the air with low distortion.
The 18 sound will also do 38mm max peak to peak excursion so will handle transients that would kill the Thomann - which is probably made by Elder Audio in China
The Theomann is quite a respectable budget driver - But it is a budget driver!
Optimized cut list
I'm lazy and have not read every single message in this thread, but here's an optimized cut list for the original MK1 THAM 15. It's super easy: you make the two long vertical cuts left to right, then the horizontal cuts are top to bottom. Note that that braces are all square as this cut list is made for a panel saw, not a router. Once you've made the square cuts it'll be up to you to then make the angled cuts. Thes cuta allow for a 1/8" kerf, but you should have plenty of waste at the end of each piece for a thicker carbide rip blade etc.
I'm lazy and have not read every single message in this thread, but here's an optimized cut list for the original MK1 THAM 15. It's super easy: you make the two long vertical cuts left to right, then the horizontal cuts are top to bottom. Note that that braces are all square as this cut list is made for a panel saw, not a router. Once you've made the square cuts it'll be up to you to then make the angled cuts. Thes cuta allow for a 1/8" kerf, but you should have plenty of waste at the end of each piece for a thicker carbide rip blade etc.
Attachments
Suppose I built four of these, and clustered them as shown here, but the second pair on top. In other words, all four mouths right next to each other.
If I understand correctly, this should give a little bit more LF extension, correct?
(If I did this, it would be for extension, not for the extra SPL.)
Is there a way to calculate that response?
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## Also: Can anyone tell me how heavy these are, when finished?
To my knowledge and testing TH's. They do not extend like FLH's do. You get a flatter response over the passband however. You could probably can lower the Highpass a bit and give each driver less juice. You do get more output with four mouths together and you get further thow.
You can simulate a tham in HR and then do multiple speakers in parallel.
This is HR sim of four Tham15's loaded with an Oberton 15B500 (about 400w at 7.5mm xmax:
This is HR sim of four Tham15's loaded with an B&C 15NW100 (about 800w at 9mm xmax:
They also work great with the cheap The Box 15 inch (15LB100-8W) driver from thoman
You can simulate a tham in HR and then do multiple speakers in parallel.
This is HR sim of four Tham15's loaded with an Oberton 15B500 (about 400w at 7.5mm xmax:
This is HR sim of four Tham15's loaded with an B&C 15NW100 (about 800w at 9mm xmax:
They also work great with the cheap The Box 15 inch (15LB100-8W) driver from thoman
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Post #427 shows an optimized cut list for the original MK1 THAM 15 coming in just under a 4'x8' - add the weight of whatever material (around 40 to 100 pounds) and driver (around 5 to 30 pounds) you choose.
Well I accidentally ended up with an extra 15SW115 and might need to build another Tham 15 (Built one two years ago for the boat that I love, with the 15tbx100). I see no one has simmed the 15SW115-4 yet for the Tham 15. Ideally I would just build another 15TBX100, but I cant send this driver back.
Would someone be willing to run the 15SW115-04 in horn resp for me. I would pay you in gratitude( still need time to become horn resp literate). Hoping it lets me play the Tham a little lower. Additional xmax and power handling wont hurt. I hope I wont have any phase issues running two different drivers close together, but we will see.
T/S
Sensitivity96.0 dB 1W/1m
Voice Coil Diameter4.5"
Thiele-Small Parameters
Resonant Frequency (Fs)34 Hz DC Resistance (Re)3.2 ohms
Voice Coil Inductance (Le)1.27 mH Mechanical Q (Qms)5.8
Electromagnetic Q (Qes)0.23 Total Q (Qts)0.22
Compliance Equivalent Volume (Vas)3.7 ft.³ BL Product (BL)25.5 Tm
Diaphragm Mass Inc. Airload (Mms)212g Maximum Linear Excursion (Xmax)12.5 mm
Surface Area of Cone (Sd)855 cm²
Thanks,
Would someone be willing to run the 15SW115-04 in horn resp for me. I would pay you in gratitude( still need time to become horn resp literate). Hoping it lets me play the Tham a little lower. Additional xmax and power handling wont hurt. I hope I wont have any phase issues running two different drivers close together, but we will see.
T/S
Sensitivity96.0 dB 1W/1m
Voice Coil Diameter4.5"
Thiele-Small Parameters
Resonant Frequency (Fs)34 Hz DC Resistance (Re)3.2 ohms
Voice Coil Inductance (Le)1.27 mH Mechanical Q (Qms)5.8
Electromagnetic Q (Qes)0.23 Total Q (Qts)0.22
Compliance Equivalent Volume (Vas)3.7 ft.³ BL Product (BL)25.5 Tm
Diaphragm Mass Inc. Airload (Mms)212g Maximum Linear Excursion (Xmax)12.5 mm
Surface Area of Cone (Sd)855 cm²
Thanks,
Both sims are probably not as accurate as they could be.
Things to look for in an accurate TH sim:
1. Any horn sections that have at least two parallel sides should be modelled as a PAR (parabolic) segment.
2. If the design does not contain any cone compensation, then the volume of air contained in front of the driver's cone plus the volume of the cutout in front of the driver need to be included in the sim (using Vtc and Atc).
3. The path in the horn should be identified and calculated using the advanced centerline method.
The las flare as "CON" was just a mistype but it will not be different from "PAR" in that specific case.
To guarantee better accuracy you should redo the design with all thinks Brian suggest and it will require parametric sketch 2D/3D CAD software.
Xoc1 use to do things with more accurate methods and this is the reason I prefer to use his model then the other for Tham15, if he reviews, there is some reason for it but I never checked.
To guarantee better accuracy you should redo the design with all thinks Brian suggest and it will require parametric sketch 2D/3D CAD software.
Xoc1 use to do things with more accurate methods and this is the reason I prefer to use his model then the other for Tham15, if he reviews, there is some reason for it but I never checked.
I have not checked but I remember that some of the sims for the Tham speakers if you check the calculated sim volume it is actually bigger than the outside volume of the cabinet.
The sims that I produced were pessimistically realistic in that they would closely match the internal volume of the speaker..
It is always worth checking the schematic volume in Hornresp as it is a good sanity check. It is easy to get excited about making an adjustment to a sim that makes it perform better - but almost invariably it ends up being bigger. Making an adjustment that is an improvement without increasing the overall volume- That's a whole different ball game!
The sims that I produced were pessimistically realistic in that they would closely match the internal volume of the speaker..
It is always worth checking the schematic volume in Hornresp as it is a good sanity check. It is easy to get excited about making an adjustment to a sim that makes it perform better - but almost invariably it ends up being bigger. Making an adjustment that is an improvement without increasing the overall volume- That's a whole different ball game!