Post #932
Hi Y'all,
I finally got the work cycle on the drawings finished. Hope they don't have too many errors.
I'll also attach the spreadsheet that I used to convert the duct heights to areas, etc. I changed the extension to .txt, you need to change it back to .xls to use it w/ Excel.
Finally, I exported the respective Hornresp files. As MMJ has already said someone has to build and measure to see what this will look like in reality.
Regards,
Hi Y'all,
I finally got the work cycle on the drawings finished. Hope they don't have too many errors.
I'll also attach the spreadsheet that I used to convert the duct heights to areas, etc. I changed the extension to .txt, you need to change it back to .xls to use it w/ Excel.
Finally, I exported the respective Hornresp files. As MMJ has already said someone has to build and measure to see what this will look like in reality.
Regards,
LOOKING GOOD !
I love your drawings TB46!
GOOD STUFF 🙂
I guess we can go ahead and call it final, and wait for someone to build, measure & report ...
I loaded up your HR sims and the raw (unstuffed) response indicates that our amount of offset may have been a bit much but the S2 placement does definitely line up well with the sketches so i went ahead and made the flare full size at 20cm depth (the approximate depth of mouth chamber ) and also adjusted S5 to reflect the actual mouth area which helped to match the response just above and below the 3rd harmonic a little better, less hole in response just below the 3rd when unstuffed .... Adding a few liters of VRC (redundant space) to help emulate the series-parallel nature of the mouth chamber (a likely feature of this design) really helped to resolve the over-offset issue with the Lab15-4 version in sim, but admittedly i'm just being nitpicky at this point
Like you said previously there is a point of diminishing returns and any more focus on this design at this point probably wont produce much improvement ...
It is what it is, a very high bandwidth very compact bandpass box, with a reasonable set of compromises ...
I did bring up the voltage on the lab sim to 60v , which still keeps it within excursion limits and is not an entirely unreasonable power level considering that this driver has a high RE value (similar to car audio subs) and is really more along the lines of a 5ohm driver .... "Magnet out" arrangement should help keep the motor cool at such high levels ...
Oh by the way, i noticed that you used very light stuffing throughout the entire path in your sims, was that to show a general panel flex loss? I moved all of the stuffing to the the first section as shown in my rough sketches, and made it more dense, it didn't make a big difference though, just reduced losses by a small amount ...
I am attaching your sims with the few mods listed above ...
P.S. Tb, have you noticed that the bandwidth looks as though it is extending out to 300hz with these last few iterations? VERY NICE! 😀
I love your drawings TB46!
GOOD STUFF 🙂
I guess we can go ahead and call it final, and wait for someone to build, measure & report ...
I loaded up your HR sims and the raw (unstuffed) response indicates that our amount of offset may have been a bit much but the S2 placement does definitely line up well with the sketches so i went ahead and made the flare full size at 20cm depth (the approximate depth of mouth chamber ) and also adjusted S5 to reflect the actual mouth area which helped to match the response just above and below the 3rd harmonic a little better, less hole in response just below the 3rd when unstuffed .... Adding a few liters of VRC (redundant space) to help emulate the series-parallel nature of the mouth chamber (a likely feature of this design) really helped to resolve the over-offset issue with the Lab15-4 version in sim, but admittedly i'm just being nitpicky at this point
Like you said previously there is a point of diminishing returns and any more focus on this design at this point probably wont produce much improvement ...It is what it is, a very high bandwidth very compact bandpass box, with a reasonable set of compromises ...
I did bring up the voltage on the lab sim to 60v , which still keeps it within excursion limits and is not an entirely unreasonable power level considering that this driver has a high RE value (similar to car audio subs) and is really more along the lines of a 5ohm driver .... "Magnet out" arrangement should help keep the motor cool at such high levels ...
Oh by the way, i noticed that you used very light stuffing throughout the entire path in your sims, was that to show a general panel flex loss? I moved all of the stuffing to the the first section as shown in my rough sketches, and made it more dense, it didn't make a big difference though, just reduced losses by a small amount ...
I am attaching your sims with the few mods listed above ...
P.S. Tb, have you noticed that the bandwidth looks as though it is extending out to 300hz with these last few iterations? VERY NICE! 😀
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All sorts of alternatives, this 12D driver is versatile
No problem Palsa! and you sound alright to me, dont worry man ! 🙂
The Loudspeaker design wizard in hornresponse make it easy and fun to load a driver into sim and fiddle around with segment sliders and area sliders, change around chamber sizes and features until you get the response and performance you are looking for...It then gets a little trickier when it is time to figure out how the design can be folded into a cabinet but you have an engineering oriented mind so you can totally do this! =D ...
TIP: It becomes much less difficult if your bandwidth requirements are not extreme and(or) if you don't mind a larger box ...
For fun i took the old 150 liter ML-Transflex (V3.1) box designed for the Lab15-4 and shrunk it down to 95 liters and 13.5" width (i did it by multiplying all chamber, segments and port areas by .65) , so it is the same exact layout, just made narrow... At 95 liters this box has the sort of output you were wanting and could be crossed over at around 150hz which is great for your OT12s 😀
Judging from the response i think that the SWS-12D could go into a smaller box and still give you what you want , but the layout would need to be different because the narrow 13.5" ML-Transflex in the attached sim is already as narrow as it can get with that driver ...
The SWS-12D driver can also work well in a tapped horn , for example: In a 133 liter Tapped horn this driver reaches the 122-123 db level! .... Very tempting!
If you REALLY wanted to go nuts and get 124db (halfspace) out of a single 12D then you could go 8th order at 140-150 liters, bandwidth is limited from 35hz to 100hz but the output is incredible! I call this one the BADASS-BANDPASS and this was the same sort of box that produces 125db with two SWE-10S4s in a 100 liter package, but the FB is 40hz with that particular 10S4 box ...
Palsa , I will attach a few sims for you 🙂 Take a look at them, they may give you some good ideas or good places to start from with HR's Loudspeaker Design Wizard ..
NOTE: Some of these sims use the 12D2 and some use the 12D4, the two drivers are pretty much interchangeable..
No problem Palsa! and you sound alright to me, dont worry man ! 🙂
The Loudspeaker design wizard in hornresponse make it easy and fun to load a driver into sim and fiddle around with segment sliders and area sliders, change around chamber sizes and features until you get the response and performance you are looking for...It then gets a little trickier when it is time to figure out how the design can be folded into a cabinet but you have an engineering oriented mind so you can totally do this! =D ...
TIP: It becomes much less difficult if your bandwidth requirements are not extreme and(or) if you don't mind a larger box ...
For fun i took the old 150 liter ML-Transflex (V3.1) box designed for the Lab15-4 and shrunk it down to 95 liters and 13.5" width (i did it by multiplying all chamber, segments and port areas by .65) , so it is the same exact layout, just made narrow... At 95 liters this box has the sort of output you were wanting and could be crossed over at around 150hz which is great for your OT12s 😀
Judging from the response i think that the SWS-12D could go into a smaller box and still give you what you want , but the layout would need to be different because the narrow 13.5" ML-Transflex in the attached sim is already as narrow as it can get with that driver ...
The SWS-12D driver can also work well in a tapped horn , for example: In a 133 liter Tapped horn this driver reaches the 122-123 db level! .... Very tempting!
If you REALLY wanted to go nuts and get 124db (halfspace) out of a single 12D then you could go 8th order at 140-150 liters, bandwidth is limited from 35hz to 100hz but the output is incredible! I call this one the BADASS-BANDPASS and this was the same sort of box that produces 125db with two SWE-10S4s in a 100 liter package, but the FB is 40hz with that particular 10S4 box ...
Palsa , I will attach a few sims for you 🙂 Take a look at them, they may give you some good ideas or good places to start from with HR's Loudspeaker Design Wizard ..
NOTE: Some of these sims use the 12D2 and some use the 12D4, the two drivers are pretty much interchangeable..
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MMJ those sims are all so tempting!! Heres the dilemma. For big & low output that I can still transport with a compact hatchback, I was planning on building 2 of your LAB15 Special boxes and loading them with the Dayton Audio PA385S-8. HR shows a single cab hitting about 124dB reliably in halfspace with 80V so I could theoretically hope for 130dB with a pair! (before an additional boundary is involved, all about that free output if possible)
I believe that's called a 150L cab (212 external) so I'd be pretty happy playing a crowd of say 100-200 in a small bar with a pair of those pups! 🙂
The whole point of this LAB12 or SWS12 cab is to be as small as possible to easily schlep to and through a college house doorway with drunk football players packed shoulder to shoulder (won't mention the cute girls, they never bothered me😉) No crazy bandwith requirements indeed! the highest I'd ever play need it to is 120-150Hz as the Fusion Alchemy 8 I plan to build for a small top to pair with this sub should be able to play down to 120 at peak SPL. the OTop12 can cross similarly low, I have it at 100Hz now with a few dB boost around x-over, might consider trying 120.
IF this cab is possible, I will build it. 22" x 18.25" x 14.5" SWS12D2 at 54V
SWS12 by natepalsa, on Flickr
But thats backburner for now. Just got asked to play at said 100-200 person bar in a little over a week!!! I have some practicing to do!!!
I believe that's called a 150L cab (212 external) so I'd be pretty happy playing a crowd of say 100-200 in a small bar with a pair of those pups! 🙂
The whole point of this LAB12 or SWS12 cab is to be as small as possible to easily schlep to and through a college house doorway with drunk football players packed shoulder to shoulder (won't mention the cute girls, they never bothered me😉) No crazy bandwith requirements indeed! the highest I'd ever play need it to is 120-150Hz as the Fusion Alchemy 8 I plan to build for a small top to pair with this sub should be able to play down to 120 at peak SPL. the OTop12 can cross similarly low, I have it at 100Hz now with a few dB boost around x-over, might consider trying 120.
IF this cab is possible, I will build it. 22" x 18.25" x 14.5" SWS12D2 at 54V
SWS12 by natepalsa, on Flickr
But thats backburner for now. Just got asked to play at said 100-200 person bar in a little over a week!!! I have some practicing to do!!!
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With this awesome config I wonder what this new 6.5 Dayton sub could do with 2 to 4 of them...
http://www.parts-express.com/dayton...utm_content=295-198&utm_campaign=email012215B
http://www.parts-express.com/dayton...utm_content=295-198&utm_campaign=email012215B
I am taking screenshots of graphs from various drivers simulated in the OD-ML-Transflex cabinets, i will post them soon .... I will add the 1260W and also the 4xDayton 6.5s ....
Freddi , your MCM looks great in one of these cabinets! You can only give it 100 watts but it produces a nice looking response curve (anything more than 28v pushes it too far beyond it's rated xmax), but for the price it is an alright deal, especially if you can get them on sale at MCM (they have some good sales on occasion) 🙂
Freddi , your MCM looks great in one of these cabinets! You can only give it 100 watts but it produces a nice looking response curve (anything more than 28v pushes it too far beyond it's rated xmax), but for the price it is an alright deal, especially if you can get them on sale at MCM (they have some good sales on occasion) 🙂
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Response graphs with various drivers in OD-ML-TRANSFLEX CABINETS
Here are some simulated response curves with various drivers in our recent Offset Mass Loaded Transflex cabs , I haven't started on the 15" drivers yet but here is some of what i have so far
The Lab12 looks alright now, but the 12D still beats it and costs much less .... The SWE-12S4 looks respectable for the price! The Rockville W12T3-S4 looks exceptionally good in a 40hz tuned box but i honestly have no idea if their published specs can be trusted, they are a newer company and not much is being said about them so far, i am tempted to order a few and put them on the DATS, but i dread the hassle of returning them if they turn out to be garbage
... 
I am somewhat impressed with how well the PA-310 and MCM-1465 performed with relatively low power levels (remember that 28v @ 8 ohms is half the power of that same voltage at 4 ohms) but also keep in mind that the cabinets were tuned up to 40hz in these cases which improves efficiency... Still, , not bad at all considering the small size of these cabinets.😀
The MCM 55-2981 and 55-2992 turned out to be somewhat disappointing in the simulations (due to their lack of motor strength), these drivers look beastly but it is really a shame that they don't perform accordingly (at least not virtually), but at least the 2981 is inexpensive ...... The 2992 is by no means the best Dollar-Per-Decibel deal out there unless you can pick them up when they are on sale (I got mine for $30 a piece!) , and it takes a 75 liter(minimum) cabinet of this type to accomodate them , the sim was at 90 liters tuned to 40hz ... The Goldwood was also not-so-hot ..
Enjoy the mixed bag,
MORE TO COME !
Here are some simulated response curves with various drivers in our recent Offset Mass Loaded Transflex cabs , I haven't started on the 15" drivers yet but here is some of what i have so far
The Lab12 looks alright now, but the 12D still beats it and costs much less .... The SWE-12S4 looks respectable for the price! The Rockville W12T3-S4 looks exceptionally good in a 40hz tuned box but i honestly have no idea if their published specs can be trusted, they are a newer company and not much is being said about them so far, i am tempted to order a few and put them on the DATS, but i dread the hassle of returning them if they turn out to be garbage
... I am somewhat impressed with how well the PA-310 and MCM-1465 performed with relatively low power levels (remember that 28v @ 8 ohms is half the power of that same voltage at 4 ohms) but also keep in mind that the cabinets were tuned up to 40hz in these cases which improves efficiency... Still, , not bad at all considering the small size of these cabinets.😀
The MCM 55-2981 and 55-2992 turned out to be somewhat disappointing in the simulations (due to their lack of motor strength), these drivers look beastly but it is really a shame that they don't perform accordingly (at least not virtually), but at least the 2981 is inexpensive ...... The 2992 is by no means the best Dollar-Per-Decibel deal out there unless you can pick them up when they are on sale (I got mine for $30 a piece!) , and it takes a 75 liter(minimum) cabinet of this type to accomodate them , the sim was at 90 liters tuned to 40hz ... The Goldwood was also not-so-hot ..
Enjoy the mixed bag,
MORE TO COME !
Attachments
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SWE12S4-60l-35hz-OD-ML-TRANSFLEX.JPG -
Rockville-W12T3-S4-60l-40hz-OD-ML-TRANSFLEX.JPG -
Pa-310-60l-40hz-OD-ML-TRANSFLEX.JPG -
MCM-2981-60l-40hz-OD-ML-TRANSFLEX.JPG -
MCM-55-1465_40hz-OD-ML-TRANSFLEX.JPG -
Lab12-60l-35hz-OD-ML-TRANSFLEX.JPG -
55-2992-90l-40hz-OD-ML-TRANSFLEX.JPG -
12PC8-60l-40hz-OD-ML-TRANSFLEX.JPG -
SWS12D2-60l-35hz-OD-ML-TRANSFLEX.JPG
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As requested
Freddi , your 1260w doesn't look bad 🙂
Laserpaddy, i also simulated four of those Dayton 6.5" drivers in a 60L OD-ML-Transflex, check out the graph, not the most cost effective, but it works ....
Tb46 asked about four 55-2421s in the 90 liter cab, here it is (based upon MCM's published specs)
Freddi , your 1260w doesn't look bad 🙂
Laserpaddy, i also simulated four of those Dayton 6.5" drivers in a 60L OD-ML-Transflex, check out the graph, not the most cost effective, but it works ....
Tb46 asked about four 55-2421s in the 90 liter cab, here it is (based upon MCM's published specs)
Will post some graphs for the 15s in a moment ..
Attachments
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Sweet thanks, pretty smallish though , I can think of a few applications....but when compared to the infinity of same size box the infinity win imo
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Yes, adding a front chamber with the reflex vent passing through the front chamber makes it a bandpass since above a certain frequency, the rear wave cancels the front wave and you have a sharp falloff. In this case the alignment is called a 6th order bandpass. Making the front chamber smaller increases the high frequency bandwidth and helps to reduce cone motion.
The Lab12 is not a bad performer in a 6th order bandpass box. It has a larger Vas and Qts, and is lower in sensitivity than the 12HP1030 but looks quite decent for a 2.08 cu ft enclosure: 117 dB SPL with -3dB at 38Hz. This is at 50 volts drive to hit 13mm xmax so it is fine for music program but not sustained sine waves as it is about 500 watts (100 above rms rating).
The design ended up at 38 liters for the rear chamber, connected to an 8 liter front chamber with a 1.6 in x 14.0 in x 34 in long wrap around channel duct, and an 8in dia exit aperture on the front chamber. Quite easy to make in my opinion, but will need bracing due to extreme pressures generated. You have to ask yourself if it is worth having two units and twice the volume to achieve the same performance as same smaller box with 12HP1030. That driver costs 2x so maybe a wash. If you have a couple of Lab12's already then it's a no brainer to make it with the Labs.
Here is the predicted performance in 2pi space with 50 volts drive and a 27Hz -24dB/oct HPF:
Here is the predicted performance with a -48dB/oct LPF at 150Hz included:
In case anyone is wondering if there will be problems with chuffing due to high vent or exit duct velocities, they are all within good reasonable limits as shown below:
Seems like a very compact 117dB setup if you ask me...
If Tb46 has the time, I am sure he can provide some nice drawings for those who can't figure out the design based on my written description. 🙂
I built a proof of concept, albeit, a tiny one, using a Dayton RS100P-4 (paper cone) 3.5 inch driver with a Karlson aperture. It is a tiny 5.5 liter box (5in wide x 9 in high x 7.5 in deep) that has an f3 of 51Hz and wide bandwidth. Predicted max SPL is 97dB at 4mm xmax. Just imagine what a 12in driver can do and how compact it will still be. I think I am naming this speaker the XKi for X's ab initio Karlson. I started from the begining with a 6th order bandpass design and converted it to a K15-like format, rather than scaling a K15, which as we all know, doesn't work too well.
http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-66.html#post4196427
SEXY!
I love the look of this little guy in the picture, the Karlson aperture is just so damned sexy !
If i ever get around to building an OD-ML-TRANSFLEX I want to experiment with a Karlson Aperture on the front, or maybe a Keystone style terminus ..... It should add enough extra loading to allow us to make the 35hz cabs only 22" tall 😀 , it would also be a more efficient use of space (as opposed to the big open mouth) i am thinking 🙂
PALSA , this could be the answer you are looking for !
I built a proof of concept, albeit, a tiny one, using a Dayton RS100P-4 (paper cone) 3.5 inch driver with a Karlson aperture. It is a tiny 5.5 liter box (5in wide x 9 in high x 7.5 in deep) that has an f3 of 51Hz and wide bandwidth. Predicted max SPL is 97dB at 4mm xmax. Just imagine what a 12in driver can do and how compact it will still be. I think I am naming this speaker the XKi for X's ab initio Karlson. I started from the begining with a 6th order bandpass design and converted it to a K15-like format, rather than scaling a K15, which as we all know, doesn't work too well.
http://www.diyaudio.com/forums/full-range/237948-speaker-kicks-butt-large-spaces-66.html#post4196427
I love the look of this little guy in the picture, the Karlson aperture is just so damned sexy !
If i ever get around to building an OD-ML-TRANSFLEX I want to experiment with a Karlson Aperture on the front, or maybe a Keystone style terminus ..... It should add enough extra loading to allow us to make the 35hz cabs only 22" tall 😀 , it would also be a more efficient use of space (as opposed to the big open mouth) i am thinking 🙂
PALSA , this could be the answer you are looking for !
A GODDAMNED SEXUAL TYRANNOSAURUS!
A KARLFLEX !!!!
HAHAHAHA I LOVE IT!
🙂
I am putting together those sims for the 15" drivers in the 90 liter version, posting them in a bit
A KARLFLEX !!!!
HAHAHAHA I LOVE IT!
🙂
I am putting together those sims for the 15" drivers in the 90 liter version, posting them in a bit
ya guyz know I NEED stuff like powerful KarlFlex speakers - I've got 15TBX40 which might qualify
(would that be almost like the T15?)
the other pair of B&C I have are
TECHNICAL DATA 15PZB40
Nominal diameter 15" ,380 mm
Nominal impedance 8 ohms
Power handling , RMS 700 W
Power handling ,cont.program 1400 W
Sensitivity (1W – 1m) 97 dB
Frequency range 40 - 2000 Hz
Voice coil diameter 100 mm
Resonance frequency , Fs 39 Hz
DC resistance , Re 5.4 ohms
Electrical Q factor , Qes 0.27
Mechanical Q factor , Qms 7.6
Total Q factor , Qts 0.26
Volume equivalent of air , VAS 137 l
Effective piston area , Sd 855 cm2
Linear excursion , X max 16 mm (p-p)
Moving mass , Mms 125 g
Force factor , BL 24.3 Tm
Voice coil inductance , Le 2 mH
Baffle cutout diam. 355 mm
Net weight 12.5 kg
Suggested cabinet / tuning 15PZB40
15TBX40
my ~70g mms K18 plays real nice
(would that be almost like the T15?)
the other pair of B&C I have are
TECHNICAL DATA 15PZB40
Nominal diameter 15" ,380 mm
Nominal impedance 8 ohms
Power handling , RMS 700 W
Power handling ,cont.program 1400 W
Sensitivity (1W – 1m) 97 dB
Frequency range 40 - 2000 Hz
Voice coil diameter 100 mm
Resonance frequency , Fs 39 Hz
DC resistance , Re 5.4 ohms
Electrical Q factor , Qes 0.27
Mechanical Q factor , Qms 7.6
Total Q factor , Qts 0.26
Volume equivalent of air , VAS 137 l
Effective piston area , Sd 855 cm2
Linear excursion , X max 16 mm (p-p)
Moving mass , Mms 125 g
Force factor , BL 24.3 Tm
Voice coil inductance , Le 2 mH
Baffle cutout diam. 355 mm
Net weight 12.5 kg
Suggested cabinet / tuning 15PZB40
15TBX40
my ~70g mms K18 plays real nice
An externally hosted image should be here but it was not working when we last tested it.
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Must be the suggestive and iconic imagery of the K-aperture at play here. 🙂
I created a new thread for the XKi (aka Karlflex) here:
http://www.diyaudio.com/forums/full-range/268524-xki-xs-ab-initio-karlson-6th-order-bandpass.html
If i made one of these offset Transflex boxes with a K aperture would anyone mind if i also called it a Karlflex?
15" drivers for the 90L Offset-ML-Transflex
Here are the simulated response curves for some 15" drivers in this 90L Offset Mass Loaded Transflex cab .... Some of these drivers did not need any filling at all, others needed some, The HDS215 needed quite a bit to flatten out, and still didn't quite get there ..
The HDS315 plays very flat but lacks efficiency and requires a lot of power for high SPLs.
The Definimax did very poorly so i am thinking about taking it off of the list in the sketch completely.....
On a positive note the Lab15-4 and the Pa385S look FANTASTIC in this box!!
P.S. I appreciate the level of efficiency with the PA385S in this relatively small box (small for a 15" driver) ...
Here are the simulated response curves for some 15" drivers in this 90L Offset Mass Loaded Transflex cab .... Some of these drivers did not need any filling at all, others needed some, The HDS215 needed quite a bit to flatten out, and still didn't quite get there ..
The HDS315 plays very flat but lacks efficiency and requires a lot of power for high SPLs.
The Definimax did very poorly so i am thinking about taking it off of the list in the sketch completely
.....On a positive note the Lab15-4 and the Pa385S look FANTASTIC in this box!!
P.S. I appreciate the level of efficiency with the PA385S in this relatively small box (small for a 15" driver) ...
Attachments
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