Shrinking the rear chamber produces results that more closely match your measurement
Freddi,
Ok, i see, The net volume for my fudged model is currently at about 80 liters, but it can be reduced ...
I just opened the simulation and found that reducing S2 (rear chamber) to give us a net volume of 64 liters moves the middle impedance peak to almost 95hz which is close to what you measured measured, FB moved up to about 60hz, and response drops off on the bottom end to match your measured response almost perfectly ..... but that is at 64 liters net ...
Freddi,
What is the thickness of the ply used to make the 115BK? and can you let me know approximately how many liters are taken up by the rear of the driver that you used when taking the measurement?
Freddi,
Ok, i see, The net volume for my fudged model is currently at about 80 liters, but it can be reduced ...
I just opened the simulation and found that reducing S2 (rear chamber) to give us a net volume of 64 liters moves the middle impedance peak to almost 95hz which is close to what you measured measured, FB moved up to about 60hz, and response drops off on the bottom end to match your measured response almost perfectly ..... but that is at 64 liters net ...
Freddi,
What is the thickness of the ply used to make the 115BK? and can you let me know approximately how many liters are taken up by the rear of the driver that you used when taking the measurement?
its made of 18mm Russian birch - fwiw I calculated 1.9 cubic feet for the rear + middle chamber (no driver) and ~1 for the front chamber - EV15L was pretty much like other ~80oz ferrite slug woofers so say 4 liters displacement so I get ~ 50 liters for the rear +middle- don't take down below the volume of the cabinet. External bulk would be 13.5" x 20.5 x 27" ~122.5 liter (wings are inset about 1.5" so total cabinet depth is 15")
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Getting closer now
Freddi ,
I think you might like this
I plugged in the EV driver and made some adjustments to the cabinet sim and the impedance peaks are lining up for the most part, the third one is a little high but other than that we are getting much closer with these inputs ...
28 liter front chamber (1 cubic foot), and 50 liter rear chamber, FB=55hz , 175 sq cm constriction at S3 and a response curve to match your measured real world response! ...
Freddi ,
I think you might like this
I plugged in the EV driver and made some adjustments to the cabinet sim and the impedance peaks are lining up for the most part, the third one is a little high but other than that we are getting much closer with these inputs ...
28 liter front chamber (1 cubic foot), and 50 liter rear chamber, FB=55hz , 175 sq cm constriction at S3 and a response curve to match your measured real world response! ...
An externally hosted image should be here but it was not working when we last tested it.
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hey MMJ - - that's really close. 115BK's path and large vent, derived by someone from K's notes (maybe Alan Zintz of Transylvania Power) is one of the smoothest K-couplers and hoping that can be used in other K. With a K-tube on top, 115BK, or a similar KK-Audio K-coupler sound pretty good despite the lack of measured LF - probably better than say a La Scala although a K400 midhorn on LS would make the two sound very much different.
115BK is very close in internal airspace to tb46's Karlflex from post 1188 so here's a rough comparison of EV15L in 115
BK to 15pzb40 in tb46's Karlflex
115BK is very close in internal airspace to tb46's Karlflex from post 1188 so here's a rough comparison of EV15L in 115
BK to 15pzb40 in tb46's Karlflex
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Hi there.
I did a new fold on the Karlflex, putting the S1 stub horizontal under the driver.
Here is FR, with round aperture, all upper stubs "active" and driver 15LB100.
As the FR suggets it did not cure the colouration so I think it is save to assume that the S1 stub itself is causing this colouration.
I like to keep the S1 for better bassextention and don't want to go the portet way, so another method of doing this TL is needed.
A norwegian guy did this fold
Interesting design worth trying
I did a new fold on the Karlflex, putting the S1 stub horizontal under the driver.
Here is FR, with round aperture, all upper stubs "active" and driver 15LB100.
As the FR suggets it did not cure the colouration
so I think it is save to assume that the S1 stub itself is causing this colouration.I like to keep the S1 for better bassextention and don't want to go the portet way, so another method of doing this TL is needed.
A norwegian guy did this fold
Interesting design worth trying
Another possible solution to the Ill mannered colourizing machine... Splitting the S1
Sebastian ,
Sorry to hear that the "folded under" style S1 did not eliminate the colouration ... So operating without an S1 still has the most acceptable sound correct?
That dip at 100hz is immense!
I am sitting here wondering why the Karlflex12 doesn't seem to suffer from the undesirable resonance effects that the wider cabinet seems to be plagued with,
and i have to wonder if it is S1 WIDTH related...?....If that is the case then the S1 could be broken up into two half-width S1 sections very simply by adding a single non-holed panel that would act as both a brace and divider... hmmm.....Would be an elegant solution if it works... at least it might be one more easy experiment for you to try out before the cabinet gets repurposed as firewood or a birdhouse ...
......But , yes, in the end if the last S1 effort does not work out very well then maybe a completely new cabinet fold could be used , like a modified version of GregB's Karlsonator fold that Freddi just suggested in his last post , it is a good fold and i don't hear people complain about any colouration problems with the Karlsonator , so it could be an option ... I actually used a modified version of that fold for one of my ML-Transflex cabinets designed around the LAB15-4 special run driver ... I have received positive feedback about that cab from a builder ..
The Norwegian fold is most definitely very interesting too ....
Hi there.
I did a new fold on the Karlflex, putting the S1 stub horizontal under the driver.
Here is FR, with round aperture, all upper stubs "active" and driver 15LB100.
View attachment 524041
As the FR suggets it did not cure the colouration
I like to keep the S1 for better bassextention and don't want to go the portet way, so another method of doing this TL is needed.
A norwegian guy did this fold
View attachment 524043
Interesting design worth trying
Sebastian ,
Sorry to hear that the "folded under" style S1 did not eliminate the colouration
... So operating without an S1 still has the most acceptable sound correct? That dip at 100hz is immense!
I am sitting here wondering why the Karlflex12 doesn't seem to suffer from the undesirable resonance effects that the wider cabinet seems to be plagued with,
and i have to wonder if it is S1 WIDTH related...?....If that is the case then the S1 could be broken up into two half-width S1 sections very simply by adding a single non-holed panel that would act as both a brace and divider... hmmm.....Would be an elegant solution if it works... at least it might be one more easy experiment for you to try out before the cabinet gets repurposed as firewood or a birdhouse ... ......But , yes, in the end if the last S1 effort does not work out very well then maybe a completely new cabinet fold could be used , like a modified version of GregB's Karlsonator fold that Freddi just suggested in his last post , it is a good fold and i don't hear people complain about any colouration problems with the Karlsonator , so it could be an option ... I actually used a modified version of that fold for one of my ML-Transflex cabinets designed around the LAB15-4 special run driver ... I have received positive feedback about that cab from a builder ..
The Norwegian fold is most definitely very interesting too ....
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Freddi ,
Good suggestion on the Karlsonator fold .. . .
Your new 7 foot folded horn with the 12 does look nice and smooth , good from 60hz straight out to almost 400hz .......
Your 115bk almost keeps up with it without quite as much bass extension , not too shabby for a cabinet that is so much smaller.
Your 7 foot horn is almost 200 liters worth of cabinet! Your Carlson is doing well considering ..
Good suggestion on the Karlsonator fold .. . .
Your new 7 foot folded horn with the 12 does look nice and smooth , good from 60hz straight out to almost 400hz .......
Your 115bk almost keeps up with it without quite as much bass extension , not too shabby for a cabinet that is so much smaller.
Your 7 foot horn is almost 200 liters worth of cabinet! Your Carlson is doing well considering ..
Matthew.
So operating without an S1 still has the most acceptable sound correct?
Yes sir, much more neutral to the tone, but bass somewhat lacking.
That dip at 100hz is immense!
That is phaserelatet, measuring 25 cm from ground 30 cm from dustcap.
No problems with the suckout at listening position.
Will try your idea with the "width theory". No matter what, then the bass is fine (below 100 hz) so I would still keep it as extra bassbin, sitting next to my sweetspot
Yes Karlsonator could also be an option, but I what to try the norwegian model first... a lot of experimentation lie ahead.
So operating without an S1 still has the most acceptable sound correct?
Yes sir, much more neutral to the tone, but bass somewhat lacking.
That dip at 100hz is immense!
That is phaserelatet, measuring 25 cm from ground 30 cm from dustcap.
No problems with the suckout at listening position.
Will try your idea with the "width theory". No matter what, then the bass is fine (below 100 hz) so I would still keep it as extra bassbin, sitting next to my sweetspot
Yes Karlsonator could also be an option, but I what to try the norwegian model first... a lot of experimentation lie ahead
.
it would be fun if your research into Kvalsvoll Design AS Compact Subwoofer Design Article
provides another way to make a smooth K-coupler
provides another way to make a smooth K-coupler
Frankenpiezos , originally a Brian Steele concept
Freddi ,
They roll in around 2.5khz on average, there is some variance on the GRS elements though, some come in as low as 2k, and others come in as high as 3k ... It is best to buy plenty of extra elements and measure them, then use the best ones ...
Yes, i have a crossover scheme, i think these Frankenpiezos would be an excellent accompaniment to an 8" high efficiency woofer .... In my opinion this type of Piezo does sound smoother when you drive them with the step up transformer, but this would make the Piezo more than loud enough to outrun an 8" driver so some padding would be needed ...
The Frankenpiezo i am using with the Karlflex has no problem at all keeping up with the Dayton PA310 12" driver (96db @1w 1m) even with the lower value swamping resistor i have on it right now (across the step-up side of the transformer, i think i am using 200 ohms currently)... If i were using a higher valued swamping resistor it would have this silly Frankenpiezo outrunning the PA310 ..
Freddi ,
They roll in around 2.5khz on average, there is some variance on the GRS elements though, some come in as low as 2k, and others come in as high as 3k ... It is best to buy plenty of extra elements and measure them, then use the best ones ...
Yes, i have a crossover scheme, i think these Frankenpiezos would be an excellent accompaniment to an 8" high efficiency woofer .... In my opinion this type of Piezo does sound smoother when you drive them with the step up transformer, but this would make the Piezo more than loud enough to outrun an 8" driver so some padding would be needed ...
The Frankenpiezo i am using with the Karlflex has no problem at all keeping up with the Dayton PA310 12" driver (96db @1w 1m) even with the lower value swamping resistor i have on it right now (across the step-up side of the transformer, i think i am using 200 ohms currently)... If i were using a higher valued swamping resistor it would have this silly Frankenpiezo outrunning the PA310 ..
I had some fun with Akabak and came up with this
This is without finetuning.
It exclude the S1 duct and thus maybe avoiding the problem I'm having.
This is without finetuning.
It exclude the S1 duct and thus maybe avoiding the problem I'm having.
Code:
System 'S1'
|The outer dimensions are ___" 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=__L, (net)
|Rear Chamber=__L, fB=40Hz,
|Front chamber=__L-ish (roughly ___L 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)
|--------------------------------------------------
|OFF
AcouResistance 'Stuffing1' Node=50=51 Ra=30e3Pas/m3 | Simulate moderate stuffing
Duct 'P0' Node=51=2
WD=48.3cm
HD=35cm
Len=24cm
VISC=1
Waveguide 'F1'
Node=2=4
wth=48.3cm hth=37cm
wmo=48.3cm hmo=42cm
Len=35cm
Conical
|---------------------------------------------
| The interchamber vent (connects the rear chamber to the front chamber)
| Be sure to account for some additional effective length if there are
|boundaries near the end of the vent.
|----------------------------------------------
Waveguide 'F2'
Node=4=5
wth=48.3cm hth=5cm
wmo=48.3cm hmo=5,5cm
Len=62cm
Conical
Waveguide 'F3'
Node=5=6
wth=48.3cm hth=5,5cm
wmo=48.3cm hmo=6cm
Len=36cm
Conical
Waveguide 'F4'
Node=6=18
wth=48.3cm hth=6cm
wmo=48.3cm hmo=6,5cm
Len=66cm
Conical
| 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 'P1' Node=5=0
WD=48,3cm
HD=4cm
Len=80cm
VISC=50
Duct 'P3' Node=5=0
WD=48,3cm
HD=4cm
Len=17cm
VISC=50
Duct 'P4' Node=5=0
WD=48,3cm
HD=3cm
Len=25cm
VISC=50
| EXPERIMENTAL CAVITY/DUCT/STUB #2
| Suggested by Freddi from DIYaudio.com
| This is a very effective method of suppressing the
| upper pipe harmonics and therefore tames and smooths response
|-----------------------------------
| Parasitic chamber
|-----------------------------------
Duct 'P5' Node=4=52
WD=48.3cm HD=5cm Len=44cm
Duct 'P6' Node=52=0
WD=48.3cm HD=10cm Len=43cm Visc=50
Duct 'P7' Node=52=53
WD=48.3cm HD=5cm Len=43cm
Radiator 'Rad1' Def='P7' Node=53
x=0 y=0 z=0 HAngle=0 VAngle=0
|-----------------------------------------------------------------------------
| APERTURE STYLE "E" SECTION
| Simple Front Chamber combined with shallow ML-Transflex style mouth
| Couples end of path with other side of cone's output (aka "Tapped") in
| regards to bass frequencies but not in the upper frequencies allowing
|6th order performance without the bandpass cutoff limitations in bandwidth.
|-----------------------------------------------------------------------------
|
| The front chamber section (above the driver), nodes reversed for tapered shape.
|
|
| The dimensions and depth of the mouth/aperture(technically also part
| of the front chamber).
|
Duct 'P2' Node=18=7
WD=48.3cm
HD=38cm
Len=2,6cm
VISC=1
Radiator 'Radiator' DEF='P2' Node=7 |Radiator or mouth dimensions defined by P2First:
Peter Steele, Frontman in Type O Negative, died 2010, age 48
then
Ronnie James Dio, Singer in Rainbow, Black Sabbath, Died 2010, age 67
Then:
Jeff Hanneman, riffmaster and iconic shredder in Slayer, died 2013, age 49
then
Lemmy, Frontman in Motörhead, died last month, age 70
And now
David Bowie, Iconic artist, now a Legend, died 10 jan. 2016, age 69
RIP
Only Lemmy reaches 70, guess it is hard to be a rockstar.....
Surprised Ozzy is still on his feet
Peter Steele, Frontman in Type O Negative, died 2010, age 48
then
Ronnie James Dio, Singer in Rainbow, Black Sabbath, Died 2010, age 67
Then:
Jeff Hanneman, riffmaster and iconic shredder in Slayer, died 2013, age 49
then
Lemmy, Frontman in Motörhead, died last month, age 70
And now
David Bowie, Iconic artist, now a Legend, died 10 jan. 2016, age 69
RIP
Only Lemmy reaches 70, guess it is hard to be a rockstar.....
Surprised Ozzy is still on his feet
I like your idea a lot !
Sebastian ,
This is extraordinarily cool !!
Like a Kvalsoll Karlflex hybrid design ... Almost as if the S1 was modified to become the throat of a TL or Horn by eliminating the end (top) termination of S1 and instead just letting it vent into the uppermost Freddi-mod stub , turning that entire length into the main interchamber duct! (but with expansion in this case) ...
It would also be easy to trim the bottom of that long duct to adjust the box tuning , easy access, SMART! ..
The parasitic chamber on the bottom can be tuned to suppress the ripple at and just above the 3rd harmonic, therefore the vented parasitic chamber effectively takes the place of S1 section !! and since it is vented it also helps to ease the air particle velocity in the rest of the system ...
Good work Sebastian!, what you have here is a brilliant idea
!
Seems to sim very smoothly too, which is a great sign, lots of potential here
Sebastian ,
This is extraordinarily cool !!
Like a Kvalsoll Karlflex hybrid design ... Almost as if the S1 was modified to become the throat of a TL or Horn by eliminating the end (top) termination of S1 and instead just letting it vent into the uppermost Freddi-mod stub , turning that entire length into the main interchamber duct! (but with expansion in this case) ...
It would also be easy to trim the bottom of that long duct to adjust the box tuning , easy access, SMART! ..
The parasitic chamber on the bottom can be tuned to suppress the ripple at and just above the 3rd harmonic, therefore the vented parasitic chamber effectively takes the place of S1 section !! and since it is vented it also helps to ease the air particle velocity in the rest of the system ...
Good work Sebastian!, what you have here is a brilliant idea
!Seems to sim very smoothly too, which is a great sign, lots of potential here
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Ozzy did enough drugs to preserve his body for eternity
Right? seems like we are in a state of constant mourning as of late, oh you know the stereotype though about how rock stars do more than their fair share of partying hard which takes it's toll, but Ozzy, yeah he has that immortal British rocker thing going for him (which David and Lemmy didn't get for some reason), so Ozzy may be shuffling around for decades to come! (at least I hope so, because he is a lovable guy, and a Grandfather of Metal!)
Ozzy Osbourne is going to outlive Miley Cyrus! (a Get Him To The Greek reference)
https://www.youtube.com/watch?v=ZvqLF9ejADE
hehehe
First:
Peter Steele, Frontman in Type O Negative, died 2010, age 48
then
Ronnie James Dio, Singer in Rainbow, Black Sabbath, Died 2010, age 67
Then:
Jeff Hanneman, riffmaster and iconic shredder in Slayer, died 2013, age 49
then
Lemmy, Frontman in Motörhead, died last month, age 70
And now
David Bowie, Iconic artist, now a Legend, died 10 jan. 2016, age 69
RIP
Only Lemmy reaches 70, guess it is hard to be a rockstar.....
Surprised Ozzy is still on his feet
Right? seems like we are in a state of constant mourning as of late, oh you know the stereotype though about how rock stars do more than their fair share of partying hard which takes it's toll, but Ozzy, yeah he has that immortal British rocker thing going for him (which David and Lemmy didn't get for some reason), so Ozzy may be shuffling around for decades to come! (at least I hope so, because he is a lovable guy, and a Grandfather of Metal!)
Ozzy Osbourne is going to outlive Miley Cyrus! (a Get Him To The Greek reference)
https://www.youtube.com/watch?v=ZvqLF9ejADE
hehehe
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Sebastian ,
This is extraordinarily cool !!
Like a Kvalsoll Karlflex hybrid design ... Almost as if the S1 was modified to become the throat of a TL or Horn by eliminating the end (top) termination of S1 and instead just letting it vent into the uppermost Freddi-mod stub , turning that entire length into the main interchamber duct! (but with expansion in this case) ...
It would also be easy to trim the bottom of that long duct to adjust the box tuning , easy access, SMART! ..
The parasitic chamber on the bottom can be tuned to suppress the ripple at and just above the 3rd harmonic, therefore the vented parasitic chamber effectively takes the place of S1 section !! and since it is vented it also helps to ease the air particle velocity in the rest of the system ...
Good work Sebastian!, what you have here is a brilliant idea
Seems to sim very smoothly too, which is a great sign, lots of potential here
Thank you, thank you...
First I'll try to fix the Karlflex and hopefully that helps. If not I can try to do this new version. I little bit more complicated with the parachamber, but in the name of science and good sound, it is a small extra effort.