you could roll a quick paper K-tube and give it a try on the Selenium. Maybe a cardboard baffle to help let it sit tilted "up" (slot "down") on top of the Karlflex. The more you describe this, the more it might displace Bill's 70Hz horn as a build. Do you think the aperture can be extended higher and not lose too much bass/introduce roughness?
I had some cool 3-way speakers with 10" and they could not handle Dan Weiss's "Tintal" - its amazing to hear him vocalize each passage before playing it on the drumkit.
I'd like to see a sketch of the current aperture
I had some cool 3-way speakers with 10" and they could not handle Dan Weiss's "Tintal" - its amazing to hear him vocalize each passage before playing it on the drumkit.
I'd like to see a sketch of the current aperture
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Tubular
Sure, i can try that out to get a measurement for you ... 🙂
Bill is "RCA-Fan" right? His 70hz horn is an entirely different sort of box , super loud with extraordinary midbass efficiency but sacrifices extension in the process ... The Karlflex on the other hand forgoes the massive midbass gains in order to get more extension and bandwidth ... "Apples and Oranges" as they say, the two boxes have different applications so the choice should depend on what role you need it to fill ..
Yes, i believe that it can be extended higher if you prefer, as long as it is a very narrow slot, i have a theory about overly wide slots negating this undersized front chamber (more detail in the sketch i am including with this post) ...
Yessir, no problem, here it is:
Oh and hey,Thanks for another great vintage Karlson ad Freddi ! I like their use of sexy innuendo to sell this sexy product! Such Iconic 50s advertising, she just needs a cigarette in her hand😛
Sure, i can try that out to get a measurement for you ... 🙂
Bill is "RCA-Fan" right? His 70hz horn is an entirely different sort of box , super loud with extraordinary midbass efficiency but sacrifices extension in the process ... The Karlflex on the other hand forgoes the massive midbass gains in order to get more extension and bandwidth ... "Apples and Oranges" as they say, the two boxes have different applications so the choice should depend on what role you need it to fill ..
Yes, i believe that it can be extended higher if you prefer, as long as it is a very narrow slot, i have a theory about overly wide slots negating this undersized front chamber (more detail in the sketch i am including with this post) ...
Yessir, no problem, here it is:
An externally hosted image should be here but it was not working when we last tested it.
Oh and hey,Thanks for another great vintage Karlson ad Freddi ! I like their use of sexy innuendo to sell this sexy product! Such Iconic 50s advertising, she just needs a cigarette in her hand😛
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I heard back from one of the guys who built the ML-Transflex for Lab15-4
UPDATE (about another design that was developed in this discussion)
I have a friend in Texas who built the ML-Transflex cabinet for the Lab15-4 , and he likes it so much that he wanted one for his Definimax 4018LF driver, so i cooked up a plan and sent that off to him, and he put one together quickly, he sent me the build pics and it looks good .. 🙂
The other day i received the following message from him shortly after a wedding DJ gig: ""Ok... real world test of the lab15-4. It works awesome. Filling a medium sized venue with great bass. First... I am not a DJ. My wife's coworker asked me to DJ her wedding... for free because I have the music and the equipment. I have the new 18" sub here too... but did not take it out of the car because I have plenty of bass with one. "
The picture is kind of dark so it isn't easy to see but that is the ML-transflex sub in the middle, compact enough to be convenient but is still capable of producing substantial SPL down to 35hz..😀
UPDATE (about another design that was developed in this discussion)
I have a friend in Texas who built the ML-Transflex cabinet for the Lab15-4 , and he likes it so much that he wanted one for his Definimax 4018LF driver, so i cooked up a plan and sent that off to him, and he put one together quickly, he sent me the build pics and it looks good .. 🙂
The other day i received the following message from him shortly after a wedding DJ gig: ""Ok... real world test of the lab15-4. It works awesome. Filling a medium sized venue with great bass. First... I am not a DJ. My wife's coworker asked me to DJ her wedding... for free because I have the music and the equipment. I have the new 18" sub here too... but did not take it out of the car because I have plenty of bass with one. "
An externally hosted image should be here but it was not working when we last tested it.
The picture is kind of dark so it isn't easy to see but that is the ML-transflex sub in the middle, compact enough to be convenient but is still capable of producing substantial SPL down to 35hz..😀
cool sub !
that's quite a survey on apertures
re: K-tube - I want you to hear one - Transylvania picked a pretty good size with 1" ID x ~5.3" long - one would think it would get more directive at HF made longer but apparently Faerber gets by with a pretty long slotted portion.
I need less stuff rather than more but would like to hear RCA-Fan's horn as its small enough to fit into some rooms. The Karlflex could stand on its own with a K-tube mounted on top.
that's quite a survey on apertures
re: K-tube - I want you to hear one - Transylvania picked a pretty good size with 1" ID x ~5.3" long - one would think it would get more directive at HF made longer but apparently Faerber gets by with a pretty long slotted portion.
I need less stuff rather than more but would like to hear RCA-Fan's horn as its small enough to fit into some rooms. The Karlflex could stand on its own with a K-tube mounted on top.
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with such a shallow baffle angle and cavity, I can see why the part above the driver may need to be closed or have a narrow leakage slot for the cavity to be "relevant" - what is the distance from cone outer edge to the lower edge of "E"'s radius cut?
Square pegs, round holes and K-tech solutions!
I think so too !, and it is good to get some more feedback on this sort of design (it is very closely related to the Karlflex)
Thank you 🙂 These are just my observations on what works with this undersized front chamber..
Looking forward to hearing this K-tube ... Do you think i should use Transylvania's chosen dimensions? Let me know .... And regular printer paper would work for something like this? Or should i get something thicker? Maybe i will employ Sebastian's technique and use some wood glue with the paper to make it strong and stiff ..
Affirmatory ............ When i opened up the K-slot too much (anything wider than narrow) it was almost as if the front chamber almost disappeared altogether and wasn't doing nearly as much to enhance the sound anymore ........ Without the front chamber acting effectively this cabinet just turns back into a plain ole offset-driver-ML-TL which is not remotely flattering for this PA310 driver at all, sounds very light and lacking on the bottom end (and mid-dominant) due to the nature of this driver ........................ Trying to make this 12" driver work full range yet sound big and bold with true 40hz extension (and no EQ) in a small box really is like trying to "fit a square peg in a round hole" which isn't likely to happen in any standard reflex box or small low tuned TL, the answer to this challenge seems to be this Karlson-tech! It is just a matter of getting this dialed-in, and i am finding out that there are some things our trusty simulators will not show us especially with an uncommon arrangement such as this ...
The lower edge of the "E" radius is cut at a vertical height equal to the edge of the driver's frame which (barely) allows access to the bolts or screws holding the driver in, and this makes inserting or removing the driver from the cabinet incredibly convenient since we aren't required to remove the front aperture panels or "wings" anymore (in order to pull or load the driver) !!!
I think so too !, and it is good to get some more feedback on this sort of design (it is very closely related to the Karlflex)
Thank you 🙂 These are just my observations on what works with this undersized front chamber..
Looking forward to hearing this K-tube ... Do you think i should use Transylvania's chosen dimensions? Let me know .... And regular printer paper would work for something like this? Or should i get something thicker? Maybe i will employ Sebastian's technique and use some wood glue with the paper to make it strong and stiff ..
Affirmatory ............ When i opened up the K-slot too much (anything wider than narrow) it was almost as if the front chamber almost disappeared altogether and wasn't doing nearly as much to enhance the sound anymore ........ Without the front chamber acting effectively this cabinet just turns back into a plain ole offset-driver-ML-TL which is not remotely flattering for this PA310 driver at all, sounds very light and lacking on the bottom end (and mid-dominant) due to the nature of this driver ........................ Trying to make this 12" driver work full range yet sound big and bold with true 40hz extension (and no EQ) in a small box really is like trying to "fit a square peg in a round hole" which isn't likely to happen in any standard reflex box or small low tuned TL, the answer to this challenge seems to be this Karlson-tech! It is just a matter of getting this dialed-in, and i am finding out that there are some things our trusty simulators will not show us especially with an uncommon arrangement such as this ...
The lower edge of the "E" radius is cut at a vertical height equal to the edge of the driver's frame which (barely) allows access to the bolts or screws holding the driver in, and this makes inserting or removing the driver from the cabinet incredibly convenient since we aren't required to remove the front aperture panels or "wings" anymore (in order to pull or load the driver) !!!
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I'd go with 5.3" length, 1/8" starting gap you could print a half ellipse, trace that pattern to pvc pipe then cut with a rotary wheel - - a one-minute K-tube, printer paper just rolled, taped then snipped might be enough to get a taste - - thinwall pvc might resonate too much - glued/layered paper might be pretty cool - I think Carl said Transylvania's tube had a 2 degree downwards taper - Walter Alan Zintz said that went with the patent (I guess Karlson's original 1951 "Acoustic Transducers")
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Hi Matthew, in the aperture drawings you vote for E. Is this improvement so big that you won't recommend using A? I like A, due to the design, kind of retro🙂
Could you please post an Akabak script for the last Karlflex? I have had a look at Akabak and want to investigate further. Would be nice with something to compare with, which node connects to next node and so on, thanx.
Cheers
Could you please post an Akabak script for the last Karlflex? I have had a look at Akabak and want to investigate further. Would be nice with something to compare with, which node connects to next node and so on, thanx.
Cheers
Now you can listen to your tubes driven by tubes ... Tubular! ...
Ok , i will get started on this🙂
Ok , i will get started on this🙂
I also find that vintage look to be visually appealing .... but damn, crummy physics
Sebastian,
I can relate because I wanted a cool retro appearance as well, but no *sigh* I am sad to say that unfortunately i cannot recommend "A" with this box unless the contour is adjusted significantly to make the slot portion above the driver very narrow and the wings obscuring the sides of the cone would need to be opened up to a great extent, so the shape would be different than the classic K-slot (unless you have a driver with a strong rising response in the upper mids and if this is the case then you could have the sides of the driver somewhat obscured by wings and end up with an extraordinarily consistent horizontal dispersion pattern in the higher frequencies , something not normally ever seen with a large diameter driver!)..... I wish there were more drivers with rising upper response starting above 800hz-ish, drivers which would also need to posses the other parameters required to work in these cabs and (and as we know that latter part is hard enough to find to begin with and especially in the right price range).
Sebastian,
I can relate because I wanted a cool retro appearance as well, but no *sigh* I am sad to say that unfortunately i cannot recommend "A" with this box unless the contour is adjusted significantly to make the slot portion above the driver very narrow and the wings obscuring the sides of the cone would need to be opened up to a great extent, so the shape would be different than the classic K-slot (unless you have a driver with a strong rising response in the upper mids and if this is the case then you could have the sides of the driver somewhat obscured by wings and end up with an extraordinarily consistent horizontal dispersion pattern in the higher frequencies , something not normally ever seen with a large diameter driver!)..... I wish there were more drivers with rising upper response starting above 800hz-ish, drivers which would also need to posses the other parameters required to work in these cabs and (and as we know that latter part is hard enough to find to begin with and especially in the right price range).
A LIST OF 15" DRIVERS FOR THE KARLFLEX, potential candidates.
RESPECTABLE GENTLEMAN OF DIYAUDIO AND BRAINIAC MASTERMINDS
A gift
I put together a small list of 15s to start ....
Why? I will explain:
Making a 12" high efficiency driver play nicely in this Karlflex design was a great exercise to help me work out the details and optimize some aspects geometry and such..... It sounds good now, but for a bigger and bolder sound i suspect that 15" drivers will be truly outstanding in one of these cabs (using a scaled up width) ..... Utilizing an affordable driver with the right parameters will allow this small box to be very competitive when size, extension, value and output are all taken into account
...
Want more output? Just build more boxes! Build a herd for large events, stack them on their sides like wide range line arrays! Splayed cluster stacks could also be an option for a large show, or a Dr Geddes style distributed sub system for more consistent bass in an acoustically difficult indoors situation!
What say ye?
We are looking for efficient drivers with low VAS figures and high motor strength, QTS that isn't too low (around .4-ish plus or minus a point ), an FS which isn't too low (ideally at or a bit above FB) , low voicecoil inductance values... Higher QMS values can increase output slightly .... Output is also limited by the linear excursion rating (XMAX) unless you are including a parasitic chamber/radiator system with your Karlflex but that is a discussion for another day ...
Ok , ready?
LETS GO SHOPPING!
Tight suspension and strong motor! Published SPL is high but may be exaggerated, VC inductance or "Le" is also high, however I love the fantastically high QMS and higher FS on this one..… PRV’s provided graph shows that when direct radiating the driver can carry out to around 1500hz … Software modeling with published figures shows good performance in a 100L Karlflex tuned to around 37hz , providing strong support down to 35hz.. (may want to verify T/S parameters with DATS or similar)
This 4 ohm version of The Kappalite 3015LF has lower VAS, higher motor strength (BL^2 divided by RE), higher QMS and more XMAX therefore has more potential than the old KL 3015LF-8 in a Karlflex cabinet operating at high bandwidth but still prefers a cabinet larger than 100L due to a lack of motor strength compared to most of the other options in this post, nevertheless it is still a useful driver, the cab width just needs to be scaled up a little more… Your back (or the back of your "roadie") will appreciate that this driver is very lightweight thanks to the neo based motor ….... Direct radiating response is good out to almost 2000hz! …... This would be a great choice, and even better if Eminence would come down on the price to be more competitive with some of these other options, otherwise it is good! (in virtual models anyway)….. Tuning the box a little higher to 40 or 45hz also helps with this one ...
This looks like a tight and strong driver for it’s price… EXCELLENT! … The low VAS combined with high motor strength and fairly low Le, (and an FS which isn’t too low) all work together to make this driver a winner in an undersized box like the Karlflex! … Not a lot of XMAX but will work in a 100L Karlflex tuned to 40hz, and should produce fairly flat and useful response up to 1 or 2 kilohertz …… THIS DRIVER IS A GREAT DISCOVERY SEBASTIAN! GOOD FIND!
This driver would be an extraordinary value if the voicecoil inductance (Le) wasn't so incredibly high on it .... It is like they used some filthy blankety-blank 🤐 car audio sub voicecoil on this thing ... Such sacrilege! Blasphemy! .... Anyway, it can work fine for bass reproduction but fails at the higher frequencies ... Works very well in a 100L Karlflex tuned to around 37hz , providing strong support down to 35hz ….. This driver is not for wide bandwidth usage, it is for BASS ONLY …
This really is a great sub driver for bass reproduction in many different cabinet styles including the Karlflex but not nearly efficient enough in the mids for a wide bandwidth application (this driver is only effective for the bass and midbass range unless you are ok with a low 86db 1w/1m efficiency in the midrange, the tonal balance would be extremely bass-heavy) Works very well in a 100L Karlflex tuned to around 37hz , providing strong support down to 35hz ….. This driver is not for wide bandwidth usage, it is for BASS ONLY …
Not bad at all ! Could use a little more power handling and XMAX but other than that looks pretty good, very lightweight and sells for a very good price (on P.E.) , very affordable for a B&C product ...
· AudioPile AP-1526-8
VAS=136L, QTS=.35 (+ or -), BL^2/RE=77.5 , Le=.7mh (according to Klippel Report)
I know that some people in the industry like to buy cables and accessories from these guys because they have good prices and good quality....Audiopile is a small yet reputable company located in Washington state and is NOT related to "Pyle" (A SoundAround brand) which is based in New York state who has a massive distribution and very spotty reputation......... Anyway, the gentleman at Audiopile who handles the drivers realized that they scored a really good product when he first tested this particular 15" model (they acquired these a few years back) ..... I talked to him about it when they were getting these in stock and he was very impressed with them, he told me that their power was underrated (350w RMS is conservative) and he rated them that way intentionally ... He also sent me the Klippel reports and i went through them .... QTS ranges between .34 and .39 depending on sample and the method used to test them , VAS is low at around 119L, VC inductance is low, XMAX is probably around 8mm one-way, cast aluminum frame ... Looks like a decent deal for $120 ... DISCLAIMER: There is always a risk with lesser known products, and after all these units are sourced out of China but to be fair so are Dayton drivers and many other brands for that matter ... This is one that you will definitely want to test with a DATS unit or similar in order to verify parameters.. AP-1526-8 | 15" 350 watt RMS Loudspeaker
This driver is a good value but unfortunately the Vas =183.2 liters which is not low enough and also lacks the motor strength to approach flat response in a 100 liter Karlflex ….The QMS figure is nice and high on these and inductance is low for a 15” driver , both very desirable traits…….. Due to the higher VAS this one would require a bigger cabinet upwards of a 170L net Karlflex with outer dimensions of something like a 24” cube shape to get closer to flat response (unless you prefer at bump in the midband bass response and don't mind a sacrifice of output around the fundamental tuning, which could be desirable when the goal is to have a punchy loud PA application sort of sound, this driver is similar to the Kappalite 3015LF-4 when it comes to the box size versus effect on response ) ….
RESPECTABLE GENTLEMAN OF DIYAUDIO AND BRAINIAC MASTERMINDS
A gift
I put together a small list of 15s to start ....
Why? I will explain:
Making a 12" high efficiency driver play nicely in this Karlflex design was a great exercise to help me work out the details and optimize some aspects geometry and such..... It sounds good now, but for a bigger and bolder sound i suspect that 15" drivers will be truly outstanding in one of these cabs (using a scaled up width) ..... Utilizing an affordable driver with the right parameters will allow this small box to be very competitive when size, extension, value and output are all taken into account
...Want more output? Just build more boxes! Build a herd for large events, stack them on their sides like wide range line arrays! Splayed cluster stacks could also be an option for a large show, or a Dr Geddes style distributed sub system for more consistent bass in an acoustically difficult indoors situation!
What say ye?
We are looking for efficient drivers with low VAS figures and high motor strength, QTS that isn't too low (around .4-ish plus or minus a point ), an FS which isn't too low (ideally at or a bit above FB) , low voicecoil inductance values... Higher QMS values can increase output slightly .... Output is also limited by the linear excursion rating (XMAX) unless you are including a parasitic chamber/radiator system with your Karlflex but that is a discussion for another day ...
Ok , ready?
LETS GO SHOPPING!
- PRV 15W1600
Tight suspension and strong motor! Published SPL is high but may be exaggerated, VC inductance or "Le" is also high, however I love the fantastically high QMS and higher FS on this one..… PRV’s provided graph shows that when direct radiating the driver can carry out to around 1500hz … Software modeling with published figures shows good performance in a 100L Karlflex tuned to around 37hz , providing strong support down to 35hz.. (may want to verify T/S parameters with DATS or similar)
- Eminence Kappalite 3015LF 4 0HM
This 4 ohm version of The Kappalite 3015LF has lower VAS, higher motor strength (BL^2 divided by RE), higher QMS and more XMAX therefore has more potential than the old KL 3015LF-8 in a Karlflex cabinet operating at high bandwidth but still prefers a cabinet larger than 100L due to a lack of motor strength compared to most of the other options in this post, nevertheless it is still a useful driver, the cab width just needs to be scaled up a little more… Your back (or the back of your "roadie") will appreciate that this driver is very lightweight thanks to the neo based motor ….... Direct radiating response is good out to almost 2000hz! …... This would be a great choice, and even better if Eminence would come down on the price to be more competitive with some of these other options, otherwise it is good! (in virtual models anyway)….. Tuning the box a little higher to 40 or 45hz also helps with this one ...
- “The Box” Brand 15LB100-8 (available in Europe)
This looks like a tight and strong driver for it’s price… EXCELLENT! … The low VAS combined with high motor strength and fairly low Le, (and an FS which isn’t too low) all work together to make this driver a winner in an undersized box like the Karlflex! … Not a lot of XMAX but will work in a 100L Karlflex tuned to 40hz, and should produce fairly flat and useful response up to 1 or 2 kilohertz …… THIS DRIVER IS A GREAT DISCOVERY SEBASTIAN! GOOD FIND!
- Dayton PA385S-8
This driver would be an extraordinary value if the voicecoil inductance (Le) wasn't so incredibly high on it .... It is like they used some filthy blankety-blank 🤐 car audio sub voicecoil on this thing ... Such sacrilege! Blasphemy! .... Anyway, it can work fine for bass reproduction but fails at the higher frequencies ... Works very well in a 100L Karlflex tuned to around 37hz , providing strong support down to 35hz ….. This driver is not for wide bandwidth usage, it is for BASS ONLY …
- Eminence Lab15-4
This really is a great sub driver for bass reproduction in many different cabinet styles including the Karlflex but not nearly efficient enough in the mids for a wide bandwidth application (this driver is only effective for the bass and midbass range unless you are ok with a low 86db 1w/1m efficiency in the midrange, the tonal balance would be extremely bass-heavy) Works very well in a 100L Karlflex tuned to around 37hz , providing strong support down to 35hz ….. This driver is not for wide bandwidth usage, it is for BASS ONLY …
- B&C 15CL76
Not bad at all ! Could use a little more power handling and XMAX but other than that looks pretty good, very lightweight and sells for a very good price (on P.E.) , very affordable for a B&C product ...
· AudioPile AP-1526-8
VAS=136L, QTS=.35 (+ or -), BL^2/RE=77.5 , Le=.7mh (according to Klippel Report)
I know that some people in the industry like to buy cables and accessories from these guys because they have good prices and good quality....Audiopile is a small yet reputable company located in Washington state and is NOT related to "Pyle" (A SoundAround brand) which is based in New York state who has a massive distribution and very spotty reputation......... Anyway, the gentleman at Audiopile who handles the drivers realized that they scored a really good product when he first tested this particular 15" model (they acquired these a few years back) ..... I talked to him about it when they were getting these in stock and he was very impressed with them, he told me that their power was underrated (350w RMS is conservative) and he rated them that way intentionally ... He also sent me the Klippel reports and i went through them .... QTS ranges between .34 and .39 depending on sample and the method used to test them , VAS is low at around 119L, VC inductance is low, XMAX is probably around 8mm one-way, cast aluminum frame ... Looks like a decent deal for $120 ... DISCLAIMER: There is always a risk with lesser known products, and after all these units are sourced out of China but to be fair so are Dayton drivers and many other brands for that matter ... This is one that you will definitely want to test with a DATS unit or similar in order to verify parameters.. AP-1526-8 | 15" 350 watt RMS Loudspeaker
- Eminence Kappa Pro15LF-C
This driver is a good value but unfortunately the Vas =183.2 liters which is not low enough and also lacks the motor strength to approach flat response in a 100 liter Karlflex ….The QMS figure is nice and high on these and inductance is low for a 15” driver , both very desirable traits…….. Due to the higher VAS this one would require a bigger cabinet upwards of a 170L net Karlflex with outer dimensions of something like a 24” cube shape to get closer to flat response (unless you prefer at bump in the midband bass response and don't mind a sacrifice of output around the fundamental tuning, which could be desirable when the goal is to have a punchy loud PA application sort of sound, this driver is similar to the Kappalite 3015LF-4 when it comes to the box size versus effect on response ) ….
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would a 15tbx40 squeeze into the standard Karlflex 15? midrange wise, its maybe 5dB less hot than a 60g mms 15" Fs 38Hz, Re 5.2, Qes 0.29, Qms 6.3, Qts 0.28, Vas 131 l/4.6 cu.ft., ref eff 2.3% , Xmax 9mm, X Var 11mm, Mms 141g, Bl 24.6, BL^2/Re = 116.37, Le 1.8mH
this is the slightly lighter moving mass 15pzb40 in a reflex vs M151 off axis (mic laying on the ground)
this is the slightly lighter moving mass 15pzb40 in a reflex vs M151 off axis (mic laying on the ground)
An externally hosted image should be here but it was not working when we last tested it.
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Very much yes
Freddi ,
The 15TBX40 looks terrific in a Karlflex-15 tuned to 40hz! At least it looks great in the "Quick & Dirty" HR test method (90 to 100 liter net range)
so it should work. SPL is in the right range , strong motor , tight suspension , low inductance, and as we know B&C is a name considered synonymous with excellence! 🙂 ...
You have one of these beasts available Freddi ?
Freddi ,
The 15TBX40 looks terrific in a Karlflex-15 tuned to 40hz! At least it looks great in the "Quick & Dirty" HR test method (90 to 100 liter net range)
so it should work. SPL is in the right range , strong motor , tight suspension , low inductance, and as we know B&C is a name considered synonymous with excellence! 🙂 ...You have one of these beasts available Freddi ?
Akabak Script for Karlflex15
Mr Sebastian Schlager,
Here is the Akabak Script for the Karlflex15 tuned to around 40hz ... I plugged in the figures for your 15LB100 , once again that driver looks like a winner! 🙂 Gets you about 120db down to 40hz in this small box at 48v ...
The aperture code on this is far more complicated than it needs to be , it can now be greatly simplified with aperture style "E" ....
I am also under the impression that this Akabak model does not fully show the benefits of the front chamber ... It guesses the placement of resonances correctly but does not seem to comprehend the degree of bass augmentation that the front chamber provides (something i determined from real listening tests while adding and removing the front panels which in essence adds and removes the front chamber) ...
I could probably go over this script a little more closely and make some very minor adjustments (a centimeter here or there) to perfectly match the true internal dimensions of the Karlflex15 but nothing that would make any significant different to performance..
There are some details about the S1 panel and main vent that i would like to mention but that will be addressed in a different post ...
Enjoy the script 😀
Mr Sebastian Schlager,
Here is the Akabak Script for the Karlflex15 tuned to around 40hz ... I plugged in the figures for your 15LB100 , once again that driver looks like a winner! 🙂 Gets you about 120db down to 40hz in this small box at 48v ...
The aperture code on this is far more complicated than it needs to be , it can now be greatly simplified with aperture style "E" ....
I am also under the impression that this Akabak model does not fully show the benefits of the front chamber ... It guesses the placement of resonances correctly but does not seem to comprehend the degree of bass augmentation that the front chamber provides (something i determined from real listening tests while adding and removing the front panels which in essence adds and removes the front chamber) ...
I could probably go over this script a little more closely and make some very minor adjustments (a centimeter here or there) to perfectly match the true internal dimensions of the Karlflex15 but nothing that would make any significant different to performance..
There are some details about the S1 panel and main vent that i would like to mention but that will be addressed in a different post ...
Enjoy the script 😀
Code:
|System FREDDITECH 5000 99LITER KARLFLEX FOR THE 15LB100-8
|The outer dimensions are 24" H x 20" W x 18.25" D with half-inch ply material
Def_Driver '15LB100'
dD=38cm |Piston
fs=40.9Hz Vas=113L Qms=7.13
Qes=0.35 Re=5.5ohm Le=1.4mH ExpoLe=0.618
System '99L-KARLFLEX'
| vt=99L, (net)
|Rear Chamber=74L, fB=40Hz,
|Front chamber=25L-ish (roughly 17L+8-ish from the Fredditech-Cavity)
|---------------------------------------------------------
| The speaker or driver :
|---------------------------------------------------------
Driver 'Driver' Def='15LB100' Node=1=0=18=2
|--------------------------------------------
| The first section (S1, S2 , S3 in Hornresponse lingo):
|--------------------------------------------
|S1=F0 (adjusting this waveguide's length adjusts the driver offset)
|P0 (make this half of your driver's diameter)
|S2=Node2 (center of driver's cone)
|s3=F1 (length is = Node2 to the bottom of main vent aka interchamber vent)
|--------------------------------------------------
Waveguide 'F0'
Node=50=51
wth=48.3cm hth=10cm
wmo=48.3cm hmo=10.1cm
Len=50.8cm
Conical
|OFF
AcouResistance 'Stuffing1' Node=50=51 Ra=30e3Pas/m3 | Simulate moderate stuffing
Duct 'P0' Node=51=2
WD=48.3cm
HD=23.5cm
Len=19cm
VISC=1
Waveguide 'F1'
Node=2=4
wth=48.3cm hth=23.5cm
wmo=48.3cm hmo=23.6cm
Len=24.5cm
Conical
|---------------------------------------------
| The interchamber vent (connects the rear chamber to the front chamber)
|----------------------------------------------
Duct 'P2' Node=4=5
WD=48.3cm
HD=6.3cm
Len=23.5cm
Visc=1
| EXPERIMENTAL CAVITY/DUCT/STUB
| Suggested by Freddi from DIYaudio.com
| This is a very effective method of suppressing the
| upper pipe harmonics and therefore tames and smooths response
Duct 'P3' Node=5=0
WD=48.3cm
HD=6.3cm
Len=35cm
VISC=50
|---------------------------------------------
| The Aperture:
|(in this case the classic K-aperture,type #1)
|The laid back orientation of the baffle and particular slot contour was
|suggested by Freddi of DIYaudio.com, who has a keen feel for Karlson technology.
| =)
|---------------------------------------------
| This first set of code defines the front chamber
|(behind the aperture and in front of the baffle)
| from top to bottom
|---------------------------------------------------
Duct 'P6' Node=5=12
WD=48.3cm
HD=9cm
Len=6.66cm
Visc=1
Duct 'P7' Node=12=13
WD=48.3cm
HD=8.25cm
Len=6.66cm
Visc=1
Duct 'P8' Node=13=14
WD=48.3cm
HD=7.5cm
Len=6.66cm
Visc=1
Duct 'P9' Node=14=15
WD=48.3cm
HD=6.75cm
Len=6.66cm
Visc=1
Duct 'P10' Node=15=16
WD=48.3cm
HD=6cm
Len=6.66cm
Visc=1
Duct 'P11' Node=16=17
WD=48.3cm
HD=5.25cm
Len=6.66cm
Visc=1
Duct 'P12' Node=17=18
WD=48.3cm
HD=4.5cm
Len=6.66cm
Visc=1
Duct 'P13' Node=18=19
WD=48.3cm
HD=3.75cm
Len=6.66cm
Visc=1
Duct 'P14' Node=19=20
WD=48.3cm
HD=3cm
Len=6.66cm
Visc=1
|---------------------------------------------------------------------
|The following code defines the gap and the depth of the K-aperture
|itself (front panel) split into 9 parts. XRK suggests 9 parts minimum =)
|---------------------------------------------------------------------
Duct 'P15' Node=12=22
WD=6cm
HD=6.66cm
Len=1.19cm
Visc=1
Duct 'P16' Node=13=23
WD=6cm
HD=6.66cm
Len=1.19cm
Visc=1
Duct 'P17' Node=14=24
WD=6cm
HD=6.66cm
Len=1.19cm
Visc=1
Duct 'P18' Node=15=25
WD=2cm
HD=6.66cm
Len=1.19cm
Visc=1
Duct 'P19' Node=16=26
WD=6.66cm
HD=6.66cm
Len=1.19cm
Visc=1
Duct 'P20' Node=17=27
WD=47.85cm
HD=6.66cm
Len=1.19cm
Visc=1
Duct 'P21' Node=18=28
WD=47.85cm
HD=6.66cm
Len=1.19cm
Visc=1
Duct 'P22' Node=19=29
WD=47.85cm
HD=6.66cm
Len=1.19cm
Visc=1
Duct 'P23' Node=20=30
WD=47.85cm
HD=6.66cm
Len=1.19cm
Visc=1
|--------------------------------------------------------------------
|(K-aperture in multiple parts)series tuned.
|The following code defines the radiator's positions and also refers
|to the ducts above for their dimensions..
|Add a pipe character in front of radiator's code line in order to
|close off that part of the slot in simulation
|--------------------------------------------------------------------
|Radiator 'Rad_P15' DEF='P15' Node=22
|x=0 y=28cm z=-9cm HAngle=0 VAngle=0
|Radiator 'Rad_P16' DEF='P16' Node=23
|x=0 y=21.33cm z=-8.25cm HAngle=0 VAngle=0
|Radiator 'Rad_P17' DEF='P17' Node=24
|x=0 y=15cm z=-7.5cm HAngle=0 VAngle=0
Radiator 'Rad_P18' DEF='P18' Node=25
x=0 y=8.33cm z=-6.75cm HAngle=0 VAngle=0
Radiator 'Rad_P19' DEF='P19' Node=26
x=0 y=0 z=-6cm HAngle=0 VAngle=0
Radiator 'Rad_P20' DEF='P20' Node=27
x=0 y=-8.33cm z=-5.25cm HAngle=0 VAngle=0
Radiator 'Rad_P21' DEF='P21' Node=28
x=0 y=-15cm z=-4.5cm HAngle=0 VAngle=0
Radiator 'Rad_P22' DEF='P22' Node=29
x=0 y=-21.33cm z=-3.75cm HAngle=0 VAngle=0
Radiator 'Rad_P23' DEF='P23' Node=30
x=0 y=-28cm z=-3cm HAngle=0 VAngle=0
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Thanx, Thomann is our Part Express 😛 Think it is a very good deal, here in Europe. I checked the price for a Dayton 310, and it is only 20 $ cheaper than The Box. I also took the Box and replaced it with the Dayton in one of your 99 liter scripts and it was very similar to the Dayton, byt with more bass but rolling of a bit sooner in the HF, as expected.
That is some work you have put in to this, thanx. I want to add this to the list.
P-Audio E15-600S 15 Inch 600W; 105£= 163$
Re 5.6 Ohm
Fs 44 Hz
Mms 124.54 g/4.39 oz
Mmd 110.16 g/3.89 oz
Qms 8.51
Qes 0.49
Qts 0.46
Vas 110.48 lt/3.90 cu ft
BI 19.82 Tm
Cms 1.1e-04 m/N
Rms 4.02 Ns/m
Le (at 1kHz) 1.13 mH
Sd 855cm2
X-max 6.5 mm/0.26 in
Gap depth 12 mm/0.47 in
Voice coil winding width 25 mm/0.98 in
A good alternative to The Box (here in Europe) i think.
That is super of you, good to hear that The Box fits well. Gotta run, have to do some simulating 😀
Cheers
I've a pair of 15tbx40 and pair of 15pzb40 - - told my builder to do RCA-fan's 70Hz horn for now. 15pzb40 has a 4" coil and is a nice looking driver
fs 43, Re 5.3, Qes 0.3, Qms 7.4, Qts 0.29, Vas 112l/4 cu ft, Sd = 132.5sq.in., Xmax 8mm, Mms 123g, BL 24.3, Le 2.4mH
fs 43, Re 5.3, Qes 0.3, Qms 7.4, Qts 0.29, Vas 112l/4 cu ft, Sd = 132.5sq.in., Xmax 8mm, Mms 123g, BL 24.3, Le 2.4mH
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