ABC/DCR , interesting audio obscurities using vented parasitic chambers
Ahhh yes , i remember how this sim works now, i have a very similar record in my Hornresp install ...... So the chamber1=40 liters , Chamber2=20 liters , and then you have three vents with a 200sq cm CSA and are a little over 2 feet long which take up about 40 liters , giving us a total internal volume of about 100 liters ..... You are given the total at the top of the "schematic" page .....
For a Dayton PA310 the three vents can be made smaller, say down to around 130cm sq CSA , and then can be made somewhat shorter as well which brings the total internal volume down to around 80hz , and we lose a few decibels of efficiency down in the 40hz-55hz range, still not bad though ...
Theoretically this sort of cabinet should allow the PA310 to take more power without risking overexcursion ...
I have a crazy OD-TL tower design with vented parasitic chamber (like a OD-DCR/ABC-TL) that i have been tempted to adapt, scale, and build for the PA310, the design worked really well for my friend that loaded it with an MTM set of smaller drivers .. .
when I tried 60 liter ABC, there was some bump on the bottom in hornresp
- 3" PVC for the outer vents and maybe 4 (?) for the inner vent might suffice for home use
Ahhh yes , i remember how this sim works now, i have a very similar record in my Hornresp install ...... So the chamber1=40 liters , Chamber2=20 liters , and then you have three vents with a 200sq cm CSA and are a little over 2 feet long which take up about 40 liters , giving us a total internal volume of about 100 liters ..... You are given the total at the top of the "schematic" page .....
For a Dayton PA310 the three vents can be made smaller, say down to around 130cm sq CSA , and then can be made somewhat shorter as well which brings the total internal volume down to around 80hz , and we lose a few decibels of efficiency down in the 40hz-55hz range, still not bad though ...
Theoretically this sort of cabinet should allow the PA310 to take more power without risking overexcursion ...
I have a crazy OD-TL tower design with vented parasitic chamber (like a OD-DCR/ABC-TL) that i have been tempted to adapt, scale, and build for the PA310, the design worked really well for my friend that loaded it with an MTM set of smaller drivers .. .
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your hybrid sounds way cool - - on the ABC = leery of vents I can't easily trim after that one BP4. Your 90 liter ABC illustration is a pretty good fit for 15pzb40 - at 69v, it goes a bit past xmax only around 100Hz. When George Augspurger first talked about the 2:1 ratio chamber reflex, there were thoughts it did something "different" - later he was able to simulate it with his mobility modeling software.
If we want to shut off a particular ABC vent in hornresp, we set vent area and length towards zero - right (?)
If we want to shut off a particular ABC vent in hornresp, we set vent area and length towards zero - right (?)
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DCR chat
That B&C 15pzb40 is a strong driver, makes it a great candidate for a DCR/ABC ... You would want to be sure to use large vents on it due to the high excursion rating on that driver, you can trade chamber size for vent size but at some point it just becomes a DC-TL
I just wish that this HR DCR/ABC model would allow us to adjust driver offsets and interchamber duct offsets in that case because that would make it extremely flexible for designing hybrids (do you suppose David is reading this? *hint* .. hehe)
That is interesting, do you remember what "different" sort of thing they thought it was doing initially?
I just tried it and it gives me an error saying that area cannot be less than .o1
Hey Freddi,
A while back when searching the web trying to find more information about DCR/ABC cabinets I remember seeing something about how these designs are supposed to function better if the external ends of the vents are kept in very close proximity , very closely coupled, does this sound familiar? There was a builder who had some good youtube videos up showing his preferred way to build DCR cabs with PA drivers , and he used a very simple method for having the ends of the vents together , a very straightforward build but unfortunately it looks like the videos are no longer available ... I may have a photo somewhere , i will have to look ...
You know it is also not hard to turn a DCR/ABC into something very Karlson-like ..
[/QUOTE]
That B&C 15pzb40 is a strong driver, makes it a great candidate for a DCR/ABC ... You would want to be sure to use large vents on it due to the high excursion rating on that driver, you can trade chamber size for vent size but at some point it just becomes a DC-TL
I just wish that this HR DCR/ABC model would allow us to adjust driver offsets and interchamber duct offsets in that case because that would make it extremely flexible for designing hybrids (do you suppose David is reading this? *hint* .. hehe)That is interesting, do you remember what "different" sort of thing they thought it was doing initially?
I just tried it and it gives me an error saying that area cannot be less than .o1
Hey Freddi,
A while back when searching the web trying to find more information about DCR/ABC cabinets I remember seeing something about how these designs are supposed to function better if the external ends of the vents are kept in very close proximity , very closely coupled, does this sound familiar? There was a builder who had some good youtube videos up showing his preferred way to build DCR cabs with PA drivers , and he used a very simple method for having the ends of the vents together , a very straightforward build but unfortunately it looks like the videos are no longer available ... I may have a photo somewhere , i will have to look ...
You know it is also not hard to turn a DCR/ABC into something very Karlson-like ..
Just looked at it. Really metaphysic talking in fact... all about "event" calcul reduced as square(2) or golden number ratios and multiple. Karlon radius calcul as result of (c+a)x square(2) where c is hypothenus are from triangle pythagore formula, and a the base. And nothing about dispersion nor according resonnances...
Merci
Thank you very much Papasteack
I saw that he had written 1.618 into his diagrams which made me curious about how he was relating Phi to the classic Karlson cabinets .....
Thank you very much Papasteack
I saw that he had written 1.618 into his diagrams which made me curious about how he was relating Phi to the classic Karlson cabinets .....
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Sketch update ... Karlflex simple , with "Schlager-Mod"
Updated sketch
Fixed a few minor errors, added a few drivers, and added the "Schlager-Mod" (should be used in the wider versions of this cabinet, but also can be used in the 60L cab if you want) ...
The Schlager-Mod is a divider panel which also acts as a brace and is meant to break up width related resonances within the S1 (offset) stub and the Freddi-mod stub ....
Updated sketch
Fixed a few minor errors, added a few drivers, and added the "Schlager-Mod" (should be used in the wider versions of this cabinet, but also can be used in the 60L cab if you want) ...
The Schlager-Mod is a divider panel which also acts as a brace and is meant to break up width related resonances within the S1 (offset) stub and the Freddi-mod stub ....
An externally hosted image should be here but it was not working when we last tested it.
Attachments
Examples of DIY
This is an example of reckless DIY, please be safe
https://www.youtube.com/watch?v=3XVtUUtfjJE
And here is an example of extreme DIY (do not attempt this unless you are a tough-as-nails cold war era badass with outstanding surgical skills, stranded in Antarctica)
Antarctica, 1961: A Soviet Surgeon Has to Remove His Own Appendix - The Atlantic
This is an example of reckless DIY, please be safe
https://www.youtube.com/watch?v=3XVtUUtfjJE
And here is an example of extreme DIY (do not attempt this unless you are a tough-as-nails cold war era badass with outstanding surgical skills, stranded in Antarctica)
Antarctica, 1961: A Soviet Surgeon Has to Remove His Own Appendix - The Atlantic
Stuff & Things
Merry Xmas Gerald! , and Happy holidays to all!
There is much to post here, been working & helping with a few different projects that use our creative alignments and arrangements .. . Some new observations ... Some updates on drivers etc ...
I plan to post here again after the Holiday weekend in order to get some things caught up to date ....
You can see much of it at the facebook group (some build logs and various ideas explored in this group) feel free to join!
DIY Speakers, Sound & Bass A-Z
Merry Xmas Gerald! , and Happy holidays to all!
There is much to post here, been working & helping with a few different projects that use our creative alignments and arrangements .. . Some new observations ... Some updates on drivers etc ...
I plan to post here again after the Holiday weekend in order to get some things caught up to date ....
You can see much of it at the facebook group (some build logs and various ideas explored in this group) feel free to join!
DIY Speakers, Sound & Bass A-Z
I'll wait patiently
Facebook is no more option for me - I just killed my account.
Happy New Year Guyz - don't forget to make K-tube tweeters and Karlson couplers
https://www.youtube.com/watch?v=NaWvtfI6FiA
https://www.youtube.com/watch?v=NaWvtfI6FiA
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HAPPY!
Happy New Year Freddi !
GKH , Zero D
Ok , the Holiday madness is behind us now for the most part over here .... .
Speaking of Karlson couplers (Freddi mentioned them) i think i may be willing to give the slot another shot .... I have a scheme in mind that will give me the lift i need between 1khz and 2khz (like an Eminence upper-mid curve) in order to make the slot work for me ... According to XSIM a simple high-q passive low pass filter may do the trick .. . I must order some parts and make it happen in the real world to confirm ..
Happy New Year Freddi !
GKH , Zero D Ok , the Holiday madness is behind us now for the most part over here .... .
Speaking of Karlson couplers (Freddi mentioned them) i think i may be willing to give the slot another shot .... I have a scheme in mind that will give me the lift i need between 1khz and 2khz (like an Eminence upper-mid curve) in order to make the slot work for me ... According to XSIM a simple high-q passive low pass filter may do the trick
.. . I must order some parts and make it happen in the real world to confirm ..
THE KARLFLEX , some thoughts
As far as the KARLFLEX cabinet in general is concerned, it works, and i am happy enough with the prototype turned out.... I have to say though that i prefer a bass rich sound as opposed to "dry" and as a single cab tuned down to 40hz i think i would have preferred the sound of a 15" PA driver for wide range usage in a Karlflex (at that tuning, as a single or a stereo set) ..... However with a 12" PA style driver in a SINGLE cabinet it seems to me that a higher tuning would have been more ideal (Freddi had the right idea on this) to subjectively balance the bass output with the midrange at the expense of extension ... ...... I emphasized the word "SINGLE" because with multiple cabinets everything changes of course as coupling and arraying of these cabinets will bring up the bottom end response more than the top end ......
FOR EXAMPLE: A set of 8 Karlflex-12 cabinets tuned to 40hz and used in some super portable PA system would be very effective with satisfying bass and no need for a subwoofer ..... Loading these cabs with Kappalite 3012LF would be especially potent in this scenario , A "slot" of a sort could be reoriented horizontally and then the cabinets laid on their sides (making the slot vertical again) and stacked on top of each other (two stacks as a stereo set , basically a mini line-array rig), should provide sufficient dispersion and output right up to around 2khz max where some high frequency array can take over (NOTE: crossover point could be made lower for less comb filtering if you can afford an HF array that goes lower) ....... Anyway, that is all theoretical as it hasn't been done yet, but if anyone would want to try such a thing just get in touch with me and we can begin the development ..... Should be a fairly straightforward process since the basic cabinet has already been figured out ...
There are some current projects in development (some detail in the next message)
As far as the KARLFLEX cabinet in general is concerned, it works
, and i am happy enough with the prototype turned out.... I have to say though that i prefer a bass rich sound as opposed to "dry" and as a single cab tuned down to 40hz i think i would have preferred the sound of a 15" PA driver for wide range usage in a Karlflex (at that tuning, as a single or a stereo set) ..... However with a 12" PA style driver in a SINGLE cabinet it seems to me that a higher tuning would have been more ideal (Freddi had the right idea on this) to subjectively balance the bass output with the midrange at the expense of extension ... ...... I emphasized the word "SINGLE" because with multiple cabinets everything changes of course as coupling and arraying of these cabinets will bring up the bottom end response more than the top end ...... FOR EXAMPLE: A set of 8 Karlflex-12 cabinets tuned to 40hz and used in some super portable PA system would be very effective with satisfying bass and no need for a subwoofer ..... Loading these cabs with Kappalite 3012LF would be especially potent in this scenario
, A "slot" of a sort could be reoriented horizontally and then the cabinets laid on their sides (making the slot vertical again) and stacked on top of each other (two stacks as a stereo set , basically a mini line-array rig), should provide sufficient dispersion and output right up to around 2khz max where some high frequency array can take over (NOTE: crossover point could be made lower for less comb filtering if you can afford an HF array that goes lower) ....... Anyway, that is all theoretical as it hasn't been done yet, but if anyone would want to try such a thing just get in touch with me and we can begin the development ..... Should be a fairly straightforward process since the basic cabinet has already been figured out ... There are some current projects in development (some detail in the next message)
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Some other ideas that have panned out well
Currently i am helping a builder friend back east (Mr Vansickle of Paragon Audio) develop a line-array module that uses dual Eminence LA12850 ... It is also a quarterwave based design , with a small amount of expansion in the path , tuned at 70hz using a compound loading scheme that eliminates the midbass response "hole" and gives us a bit of gain..... So instead of using the driver-offset along with tuned & stuffed stubs (as were employed in the Karlflex) to flatten and extend response this new design takes a different approach, compound loading .......The setup produces quite a lot of output before reaching rated linear excursion limits
......................This is the second time we have used this particular compound loading scheme with dual 12" drivers professionally .... The first time was with dual PA310s in some 3-way Club Tops which are currently being used at a nightclub in North Carolina .......... Those cabinets ended up meeting all of our expectations and then some, the low frequency section performs like a kickbin with extended upper response. .. .....
I will have to post some photos and sketches ....
Some guys over in Europe have popularized "Planar Wave Horn" style subwoofers, and we are taking the idea further by adding quarter-wave loading on the main path and using the compound loading to fill in the 3/4-4/4 ripple and hole, so we have been calling this "SUPER PLANAR" compound loading , although i am not really sure if "Planar" is the proper term for this so we may just end up calling it something else .... Haven't decided yet
Currently i am helping a builder friend back east (Mr Vansickle of Paragon Audio) develop a line-array module that uses dual Eminence LA12850 ... It is also a quarterwave based design , with a small amount of expansion in the path , tuned at 70hz using a compound loading scheme that eliminates the midbass response "hole" and gives us a bit of gain..... So instead of using the driver-offset along with tuned & stuffed stubs (as were employed in the Karlflex) to flatten and extend response this new design takes a different approach, compound loading .......The setup produces quite a lot of output before reaching rated linear excursion limits
......................This is the second time we have used this particular compound loading scheme with dual 12" drivers professionally .... The first time was with dual PA310s in some 3-way Club Tops which are currently being used at a nightclub in North Carolina .......... Those cabinets ended up meeting all of our expectations and then some, the low frequency section performs like a kickbin with extended upper response. .. ..... I will have to post some photos and sketches ....
Some guys over in Europe have popularized "Planar Wave Horn" style subwoofers, and we are taking the idea further by adding quarter-wave loading on the main path and using the compound loading to fill in the 3/4-4/4 ripple and hole, so we have been calling this "SUPER PLANAR" compound loading , although i am not really sure if "Planar" is the proper term for this so we may just end up calling it something else .... Haven't decided yet
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Piezo horn square
By the way , who was asking about refining some square piezo horns a while back? Was it GM or someone else? This conversation has grown so long now ..... I suppose i could scroll through the pages to find the exchange .... I have something that works VERY well as a piezo horn body with square dimensions ..... I was pleasantly surprised to find out that these measure better than the Goldwood 1016 horn body!
By the way , who was asking about refining some square piezo horns a while back? Was it GM or someone else? This conversation has grown so long now ..... I suppose i could scroll through the pages to find the exchange .... I have something that works VERY well as a piezo horn body with square dimensions ..... I was pleasantly surprised to find out that these measure better than the Goldwood 1016 horn body!
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