1949 was a good year
Ozzy's ~1.3 years older than myself - what a drag it is gettin' old
LMAO - fwiw hit in 3-50 but am older than the Karlson speaker's appearance (summer 1951 for K15 - it was invented by at least early 1950) and my kid says I'm lots older than the automatic coffee pot
Who invented the fully automatic Coffee Maker?
Who invented the fully automatic Coffee Maker?
Checking out the new fold
Sebastian ,
I took some time to get familiarized with the new fold .... I made a simplified version in an attempt to fit it into the compact Karlflex-esque dimensions of 24" height and 18.25" depth .... Leaving out the Para-Chamber and the extra Freddi-mod stubs (going with only one) and it works!
Not as smooth as your larger complex version, but it does work ....
So far it seems to me that this fold is well suited to a slightly larger cabinet volume however cone control is improved for a given size which is good, at the expense of a marginally raised F3 (all characteristics of less driver offset, so it is to be expected) ......
Obtaining smooth response (as you accomplished in your model) without using a significant driver offset in the arrangement really does appear to call for the multi-Freddi stub approach in conjunction with the para-chamber in order to fully hammer down and smooth out the response ripple caused by harmonics, especially the ripple caused by the 3rd harmonic which would otherwise likely show up as a peak followed by drastic dip in the midbass response, but these features that you added to the cabinet design straightened it all out quite nicely ....
These are just a few initial impressions after test driving this fold in Akabak for a short amount of time, it looks totally viable to me so far
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.
Sebastian ,
I took some time to get familiarized with the new fold .... I made a simplified version in an attempt to fit it into the compact Karlflex-esque dimensions of 24" height and 18.25" depth .... Leaving out the Para-Chamber and the extra Freddi-mod stubs (going with only one) and it works!
Not as smooth as your larger complex version, but it does work .... So far it seems to me that this fold is well suited to a slightly larger cabinet volume however cone control is improved for a given size which is good, at the expense of a marginally raised F3 (all characteristics of less driver offset, so it is to be expected) ......
Obtaining smooth response (as you accomplished in your model) without using a significant driver offset in the arrangement really does appear to call for the multi-Freddi stub approach in conjunction with the para-chamber in order to fully hammer down and smooth out the response ripple caused by harmonics, especially the ripple caused by the 3rd harmonic which would otherwise likely show up as a peak followed by drastic dip in the midbass response, but these features that you added to the cabinet design straightened it all out quite nicely ....
These are just a few initial impressions after test driving this fold in Akabak for a short amount of time, it looks totally viable to me so far
Sorry to drop in from other forums but I do wonder if you have updated the Karlflex, which I may have coined the name of, for the LAB 12, which I can get just for reconing from my pro sound buddy Pete who runs 8 Labhorns in his big rig and 4 PAL 12s in his small one. Since I'm the same age as D Bowie and A Rickmann I feel time is short and I can't delay doing something along these lines. I would go for low frequency extension over spl, btw.
I'm an old skool TL maker so angled baffles don't scare me. Diffraction is a bugaboo in the horn/waveguide world so I am hesitant about the Karlson aperture but what if I like it? Will Dr G disown me?
I'm an old skool TL maker so angled baffles don't scare me. Diffraction is a bugaboo in the horn/waveguide world so I am hesitant about the Karlson aperture but what if I like it? Will Dr G disown me?
Last edited:
Still sad about D Bowie, and now A Rickman, if their age you must buck the trend!
BUCK THE TREND, LIVE FOREVER!
Phivates ,
I hope Dr G won't disown you..
Karlflex is an amazing name, so if you are responsible for that I am very thankful
The Karlflex12 works for the Lab12 and the Karlflex12 prototype has been built and sounds good Our friend in Denmark also built a wider 20" version for 15" drivers and there is a bit of a resonance issue generated in the S1 (offset) section which is still being sorted out and is likely width related (and hopefully will be resolved with a divider), nevertheless it does not seem to be a problem with the 13.5" cab width for 12" drivers ..
If you are an old school TL maker then this thing should be a breeze for you to build.
For the lower tuning you will want to use the optional duct extension panel .... plans are at post #1611
http://www.diyaudio.com/forums/subw...d-series-tuned-6th-order-162.html#post4481439
BUCK THE TREND, LIVE FOREVER!
Phivates ,
I hope Dr G won't disown you..
Karlflex is an amazing name, so if you are responsible for that I am very thankful
The Karlflex12 works for the Lab12 and the Karlflex12 prototype has been built and sounds good
Our friend in Denmark also built a wider 20" version for 15" drivers and there is a bit of a resonance issue generated in the S1 (offset) section which is still being sorted out and is likely width related (and hopefully will be resolved with a divider), nevertheless it does not seem to be a problem with the 13.5" cab width for 12" drivers .. If you are an old school TL maker then this thing should be a breeze for you to build.
For the lower tuning you will want to use the optional duct extension panel .... plans are at post #1611
http://www.diyaudio.com/forums/subw...d-series-tuned-6th-order-162.html#post4481439
Last edited:
Phivates, The man who coined the name Karlflex
By golly there it is! That was you!
You have made an awesome contribution
That name had sticking power while everything else in the design was refined, rearranged and adjusted
By golly there it is! That was you!
You have made an awesome contribution
That name had sticking power while everything else in the design was refined, rearranged and adjusted
Progress on the Karlflex
I have good news from the Karlflex experimentationfront. I did a full bracing in the S1 duct, so it has two areas 8x24x58 cm, and it did indeed help a lot.
Most of the bad colouration is gone, still some left, but definitely better. So as Mr. Matthew pointed out, it was quater wave relatet in S1, nice call
Here are some FR measurements.
First FR is old version without full bracing/divider
Here new version with full bracing in S1
And a couple more with different measuring distance.
Looking at FR 1 and 2, there is a dip a 40 hz with full bracing ?.. but on the other hand the dip at 100 hz is not so bad. And at longer distance 40 hz is full in amplitude, so no problem i guess.
But what is much more important is the FR from 150-500 which is lot nicer in FR 2 and it is, for sure, much more enjoyable to listen to 
Next build will be with para-chamber and a longer TL, avoiding S1 altogether. It will be interesting to hear that, compared to this box.
I have good news from the Karlflex experimentationfront. I did a full bracing in the S1 duct, so it has two areas 8x24x58 cm, and it did indeed help a lot.
Most of the bad colouration is gone, still some left, but definitely better. So as Mr. Matthew pointed out, it was quater wave relatet in S1, nice call
Here are some FR measurements.
First FR is old version without full bracing/divider
Here new version with full bracing in S1
And a couple more with different measuring distance.
Looking at FR 1 and 2, there is a dip a 40 hz with full bracing ?.. but on the other hand the dip at 100 hz is not so bad. And at longer distance 40 hz is full in amplitude, so no problem i guess.
But what is much more important is the FR from 150-500 which is lot nicer in FR 2
and it is, for sure, much more enjoyable to listen to Next build will be with para-chamber and a longer TL, avoiding S1 altogether. It will be interesting to hear that, compared to this box.
SEBASTIAN SOLVED THE MYSTERY OF THE INSUFFERABLE DRIVER OFFSET STUB SECTION!!
GREAT WORK SEBASTIAN!!
Thank you so very much for performing this experiment I imagine that it is dreadfully cold in your workshop right now (i hope you had some sort of heating), the Gods of science surely appreciate your dedication and will smile down upon you with blessings of good fortune in your quest for sonic perfection!!!
I am really glad to hear that the Karlflex15-special is much more enjoyable to listen to now, would you also say that the deep bass extension has returned with this version of S1 as opposed to not having the S1 at all? In other words are you given the impression that the bottom end now sounds similar to how it sounded with the original S1? (excluding the nasty colouration of course) ...
Sebastian, with your work here i think you have basically verified that the colouration was caused by some resonance effects related to the width of the S1 stub section (maybe associated with the width dimension approaching the length dimension, a divider fixes that for sure) .............
If we are talking about quarter wave resonances then the s1's internal width and length would suggest that the ugly honking colourations were probably falling into the 130hz to 170hz-ish range (possibly also with harmonics at odd multiples) even if the energy that excited those resonances fell outside of that fundamental range ...... Does that sound anything like what you were hearing?
I apologize for all of the questions, i am just working on a theory...
I think i may update the Karlflex sketch to include the "Schlager-mod" divider-brace for all cabinet widths .... Do you like the name? hehehe
I have good news from the Karlflex experimentationfront. I did a full bracing in the S1 duct, so it has two areas 8x24x58 cm, and it did indeed help a lot.
Most of the bad colouration is gone, still some left, but definitely better. So as Mr. Matthew pointed out, it was quater wave relatet in S1, nice call
Here are some FR measurements.
First FR is old version without full bracing/divider
Looking at FR 1 and 2, there is a dip a 40 hz with full bracing ?.. but on the other hand the dip at 100 hz is not so bad. And at longer distance 40 hz is full in amplitude, so no problem i guess.
But what is much more important is the FR from 150-500 which is lot nicer in FR 2
Next build will be with para-chamber and a longer TL, avoiding S1 altogether. It will be interesting to hear that, compared to this box.
GREAT WORK SEBASTIAN!!
Thank you so very much for performing this experiment
I imagine that it is dreadfully cold in your workshop right now (i hope you had some sort of heating), the Gods of science surely appreciate your dedication and will smile down upon you with blessings of good fortune in your quest for sonic perfection!!! I am really glad to hear that the Karlflex15-special is much more enjoyable to listen to now, would you also say that the deep bass extension has returned with this version of S1 as opposed to not having the S1 at all? In other words are you given the impression that the bottom end now sounds similar to how it sounded with the original S1? (excluding the nasty colouration of course) ...
Sebastian, with your work here i think you have basically verified that the colouration was caused by some resonance effects related to the width of the S1 stub section (maybe associated with the width dimension approaching the length dimension, a divider fixes that for sure) .............
If we are talking about quarter wave resonances then the s1's internal width and length would suggest that the ugly honking colourations were probably falling into the 130hz to 170hz-ish range (possibly also with harmonics at odd multiples) even if the energy that excited those resonances fell outside of that fundamental range ...... Does that sound anything like what you were hearing? I apologize for all of the questions, i am just working on a theory...
I think i may update the Karlflex sketch to include the "Schlager-mod" divider-brace for all cabinet widths .... Do you like the name? hehehe
Last edited:
Thank you so very much for performing this experiment
I imagine that it is dreadfully cold in your workshop right now (i hope you had some sort of heating), the Gods of science surely appreciate your dedication and will smile down upon you with blessings of good fortune in your quest for sonic perfection!!!
Thank you, my pleasure. Only glad to chip in the bowl of knowledge
Yep without my gas-heater, it would be to cold to be in the garage.
With effort, results will eventually show up.
I am really glad to hear that the Karlflex15-special is much more enjoyable to listen to now, would you also say that the deep bass extension has returned with this version of S1 as opposed to not having the S1 at all? In other words are you given the impression that the bottom end now sounds similar to how it sounded with the original S1? (excluding the nasty colouration of course) ...
Yes, I believethat the bass is a little more full, natural, complete, with the TL, but not much. It may not be a fair comparison, because the "reflex-box" was not tuned properly, only a by-product/consequence of removing the S1 panel.
I'll have to confirm more closely with my measurements, but my ears tell me so.
Sebastian, with your work here i think you have basically verified that the colouration was caused by some resonance effects related to the width of the S1 stub section (maybe associated with the width dimension approaching the length dimension, a divider fixes that for sure) .............
If we are talking about quarter wave resonances then the s1's internal width and length would suggest that the ugly honking colourations were probably falling into the 130hz to 170hz-ish range (possibly also with harmonics at odd multiples) even if the energy that excited those resonances fell outside of that fundamental range ...... Does that sound anything like what you were hearing?
I apologize for all of the questions, i am just working on a theory...
Looking at the FR 1 in post 1948, there seem to be a pattern in the dips and peaks.
The first peak tops at 155 Hz,
2. peak at around 237hz.
3. peak at 335hz.
1. dip at 180.
2. dip at 260hz.
3. dip 370hz
Normally a resonanse doesn't produce dips. Could it be phaserelatet ??
It is to small a contribution to be credited and it was you who pointed it out
Thank you, my pleasure. Only glad to chip in the bowl of knowledge
With effort, results will eventually show up.
I am really glad to hear that the Karlflex15-special is much more enjoyable to listen to now, would you also say that the deep bass extension has returned with this version of S1 as opposed to not having the S1 at all? In other words are you given the impression that the bottom end now sounds similar to how it sounded with the original S1? (excluding the nasty colouration of course) ...
Yes, I believethat the bass is a little more full, natural, complete, with the TL, but not much. It may not be a fair comparison, because the "reflex-box" was not tuned properly, only a by-product/consequence of removing the S1 panel.
I'll have to confirm more closely with my measurements, but my ears tell me so.
Sebastian, with your work here i think you have basically verified that the colouration was caused by some resonance effects related to the width of the S1 stub section (maybe associated with the width dimension approaching the length dimension, a divider fixes that for sure) .............
I apologize for all of the questions, i am just working on a theory...
Looking at the FR 1 in post 1948, there seem to be a pattern in the dips and peaks.
The first peak tops at 155 Hz,
2. peak at around 237hz.
3. peak at 335hz.
1. dip at 180.
2. dip at 260hz.
3. dip 370hz
Normally a resonanse doesn't produce dips. Could it be phaserelatet ??
It is to small a contribution to be credited and it was you who pointed it out
Mono test
I did a mono test of the Karlflex box, with the paper horn I made for it. It has a Faital Pro 3" full range driver.
I use active x-over at 900 hz and digital delay. Still some isues in the Karlflex. Especial with drums, where the snare has a hollow sound, probably a driver isue more than box relatet. Other critic, is that the drivers are too far apart, so it is not so coherent.
The good thing is that overall, it has a big dynamic sound, with punch and attack. The 150-500 hz range still is somewhat coloured, as mentioned, but it has bite and impact, normal monkey coffins, can only dream of. Because of high sensitivity, around 96 db, it does not compress at high volumes, as normal hifi speakers do.
The 3" driver/horn combo has... well hornsound, with all the horn virtues. Very impressed with this little driver, costing only 30 bucks. I'm used to big JBL 2445 driver on big horns and the difference is not that big.
Clear and open sound, with lots of details and transient attack, can't ask for more.
This speaker is definitely a different animal, with lots of virtues, that sets it apart from "the pack"
Next project will be Karlflex with long TL and para-camber. The para-chamber will also elevate the bass driver, so it will be closer to the horn. A free bonus.
I did a mono test of the Karlflex box, with the paper horn I made for it. It has a Faital Pro 3" full range driver.
I use active x-over at 900 hz and digital delay. Still some isues in the Karlflex. Especial with drums, where the snare has a hollow sound, probably a driver isue more than box relatet. Other critic, is that the drivers are too far apart, so it is not so coherent.
The good thing is that overall, it has a big dynamic sound, with punch and attack. The 150-500 hz range still is somewhat coloured, as mentioned, but it has bite and impact, normal monkey coffins, can only dream of. Because of high sensitivity, around 96 db, it does not compress at high volumes, as normal hifi speakers do.
The 3" driver/horn combo has... well hornsound, with all the horn virtues. Very impressed with this little driver, costing only 30 bucks. I'm used to big JBL 2445 driver on big horns and the difference is not that big.
Clear and open sound, with lots of details and transient attack, can't ask for more.
This speaker is definitely a different animal, with lots of virtues, that sets it apart from "the pack"
Next project will be Karlflex with long TL and para-camber. The para-chamber will also elevate the bass driver, so it will be closer to the horn. A free bonus.
Harmonics are not always harmonious!
Good to hear and Yes , you are absolutely correct, without the S1 the cabinet was tuned a bit higher..
At least three different things are happening simultaneously ...
Your peaks could be a combination of odd harmonics, constructive wave interactions, and room effects since you are measuring indoors. The dips can also be a combination of room effects and also as you said phase related effects at the box, also called destructive interference (cancellation due to cabinet design)..
In a box like this when the output phase from the quarter wave resonator at a particular frequency lines up with the phase of what is coming out of the front of the cone they support each other and you get a bump or peak in response, and vice versa when (at the mouth) the wave from the two sources get anywhere close to 180 degrees out of phase from one another at a particular frequency there will be a dip (or a notch in extreme cases) ......... Our use of stubs and stuffing really help to control these problems .. Stuffing actually has the ability to absorb some of those problematic upper pipe harmonics ...
Good to hear
and Yes , you are absolutely correct, without the S1 the cabinet was tuned a bit higher.. The first peak tops at 155 Hz,
2. peak at around 237hz.
3. peak at 335hz.
1. dip at 180.
2. dip at 260hz.
3. dip 370hz
Normally a resonanse doesn't produce dips. Could it be phaserelatet ??
It is to small a contribution to be credited and it was you who pointed it out
At least three different things are happening simultaneously ...
Your peaks could be a combination of odd harmonics, constructive wave interactions, and room effects since you are measuring indoors. The dips can also be a combination of room effects and also as you said phase related effects at the box, also called destructive interference (cancellation due to cabinet design)..
In a box like this when the output phase from the quarter wave resonator at a particular frequency lines up with the phase of what is coming out of the front of the cone they support each other and you get a bump or peak in response, and vice versa when (at the mouth) the wave from the two sources get anywhere close to 180 degrees out of phase from one another at a particular frequency there will be a dip (or a notch in extreme cases) ......... Our use of stubs and stuffing really help to control these problems .. Stuffing actually has the ability to absorb some of those problematic upper pipe harmonics ...
I love the look of that DIY midhorn
I remember a few months ago you sent to me a room recording of some blues track with a prominent snare, and back then the snare definitely sounded exceptionally weird, I am curious to see what that same track sounds like now .......
In order to get the drivers closer together you could just turn your Karlflex15-special upside down.
hehe
A great band name would be "Monkey Coffin Dreams"
Which $30 dollar Faital Pro driver did you use for your handcrafted horn?
I remember a few months ago you sent to me a room recording of some blues track with a prominent snare, and back then the snare definitely sounded exceptionally weird, I am curious to see what that same track sounds like now .......
In order to get the drivers closer together you could just turn your Karlflex15-special upside down.
hehe Sounds like it inherited some of the Karlson characteristics
A great band name would be "Monkey Coffin Dreams"
The 3" driver/horn combo has... well hornsound, with all the horn virtues. Very impressed with this little driver, costing only 30 bucks. I'm used to big JBL 2445 driver on big horns and the difference is not that big.
Clear and open sound, with lots of details and transient attack, can't ask for more.
This speaker is definitely a different animal, with lots of virtues, that sets it apart from "the pack"
Next project will be Karlflex with long TL and para-camber. The para-chamber will also elevate the bass driver, so it will be closer to the horn. A free bonus.
Which $30 dollar Faital Pro driver did you use for your handcrafted horn?
Last edited:
I am fond of this Dayton PA310
Freddi,
I have much respect for the Dayton PA310-8, it is really hard to find a better low budget high efficiency Pro 12 in that price range .... The more i work with these Daytons the more i really appreciate them .... After lots of break-in time they have a great sound , and have parameters that are useful in the types of cabinets that we have been working with here in this discussion ...
I did simulate the ABC/DCR 60 liter loaded with PA310 in Hornresp and it does look attractive ... When it comes to ABC/DCR designs i have found that it depends on what software you use to sim them , i have a version of winISD that will sim ABC cabs and in that software it seems that the PA310 will want a bigger cabinet for that alignment ..
The Original experimental Karlflex12 that i build which included the vented parasitic chamber is very much like a DCR/ABC cabinet but with series tuned 6th order loading and a long path like a transflex or tapped pipe , and it worked well once i got the aperture right .... It had about 90 liters of internal volume ...
(I'd like a list of CD with well recorded/dynamic snare)- PA310-8 is in a sweet spot with enough sensitivity & displacement plus a nice price
Freddi,
I have much respect for the Dayton PA310-8, it is really hard to find a better low budget high efficiency Pro 12 in that price range .... The more i work with these Daytons the more i really appreciate them
.... After lots of break-in time they have a great sound , and have parameters that are useful in the types of cabinets that we have been working with here in this discussion ...I did simulate the ABC/DCR 60 liter loaded with PA310 in Hornresp and it does look attractive ... When it comes to ABC/DCR designs i have found that it depends on what software you use to sim them , i have a version of winISD that will sim ABC cabs and in that software it seems that the PA310 will want a bigger cabinet for that alignment ..
The Original experimental Karlflex12 that i build which included the vented parasitic chamber is very much like a DCR/ABC cabinet but with series tuned 6th order loading and a long path like a transflex or tapped pipe , and it worked well once i got the aperture right .... It had about 90 liters of internal volume ...
Contemplating these real world Definimonster4012HO custom recone measurements
For the last couple of days i have one of these Definimonster drivers (custom 4012ho recone) loaded in the Karlflex12 prototype, just temporarily for testing... It is definitely different than the PA310 ...... The low compliance suspension on this thing (VAS somewhere in the 30s) is tough as nails and i am having a hard time getting them to break in further, but i will keep working on it
....
NOTE: Pondering something, It is possible that i am being shown a physics lesson regarding driver compliance and how it relates to the common practice of operating with the cabinet tuning below driver FS within long path cabinet designs which works well enough in most cases because the long column of air adds weight, a sort of added moving mass that allows the driver to behave like a driver with a lower free-air resonance (to provide support for reproduction of the lower frequencies if the cab is tuned lower but within reason, as low as FS*.618 for example) HOWEVER it may be problematic with drivers that have unusually low VAS figures because in this scenario if the VAS figure is exceptionally low it might be better to have a driver FS that does not exceed your desired FB (due to the fact that the weight of our long column of air won't effect a driver with extremely tight suspension nearly as much), something that HORNRESP did not indicate to me, and may be something to keep in mind when trying to choose an ideal driver for maximum performance ... At least that is the impression i am getting at the moment while i am attempting to sort out the simulated/measured discrepancies (at FB which is 10hz below FS, that is where i am seeing the problem, after some break-in there is some noticeable improvement, but still could be much better i think) ..
For the last couple of days i have one of these Definimonster drivers (custom 4012ho recone) loaded in the Karlflex12 prototype, just temporarily for testing... It is definitely different than the PA310 ...... The low compliance suspension on this thing (VAS somewhere in the 30s) is tough as nails and i am having a hard time getting them to break in further, but i will keep working on it
.... NOTE: Pondering something, It is possible that i am being shown a physics lesson regarding driver compliance and how it relates to the common practice of operating with the cabinet tuning below driver FS within long path cabinet designs which works well enough in most cases because the long column of air adds weight, a sort of added moving mass that allows the driver to behave like a driver with a lower free-air resonance (to provide support for reproduction of the lower frequencies if the cab is tuned lower but within reason, as low as FS*.618 for example) HOWEVER it may be problematic with drivers that have unusually low VAS figures because in this scenario if the VAS figure is exceptionally low it might be better to have a driver FS that does not exceed your desired FB (due to the fact that the weight of our long column of air won't effect a driver with extremely tight suspension nearly as much), something that HORNRESP did not indicate to me, and may be something to keep in mind when trying to choose an ideal driver for maximum performance ... At least that is the impression i am getting at the moment while i am attempting to sort out the simulated/measured discrepancies (at FB which is 10hz below FS, that is where i am seeing the problem, after some break-in there is some noticeable improvement, but still could be much better i think) ..
Last edited:
I love the look of that DIY midhorn
Thanks, yes it is a nice DIYhorn and the great thing is that it works very well and not that hard to make. And it can be made to different bandwidth. In my big rig the JBL 2445 in a 60 cm horn can go to 400 Hz.
Good idea of turning the sub upside down. Will give a more coherent sound.
The driver for the horn is a Faital Pro 3FE25 and only 20 bucks in US, a steal for that money, if you ask me.
Thanks, yes it is a nice DIYhorn and the great thing is that it works very well and not that hard to make. And it can be made to different bandwidth. In my big rig the JBL 2445 in a 60 cm horn can go to 400 Hz.
Good idea of turning the sub upside down. Will give a more coherent sound.
The driver for the horn is a Faital Pro 3FE25 and only 20 bucks in US, a steal for that money, if you ask me.