Once I get back to Canada and get my shop in order, I am going to try to investigate this foam vs wood conundrum. The Karlsons were all made of wood or MDF years ago, Planet 10 and others are making small speakers out of wood, plywood, MDF etc. Tons of builders on the PE forum are making small apeakers from plywood, MDF, and other.
It makes no engineering sense that the mini Karsonators cannot be made of wood and filled with appropriate stuffing to make them sound good. (I was an engineer, but now I am a novice electronics guy, looking to learn and experiment).
Does anybody know what makes the foam enclosures suit these drivers. I can not see the foam being reflective and I can believe that the foam absorbs a lot of the rear wave.
I am interested in finding an answer, as I like to work with wood.
Maybe we need a new thread for this research so as not to hijack xrk's thread.
Help from moderators?
Myles
It makes no engineering sense that the mini Karsonators cannot be made of wood and filled with appropriate stuffing to make them sound good. (I was an engineer, but now I am a novice electronics guy, looking to learn and experiment).
Does anybody know what makes the foam enclosures suit these drivers. I can not see the foam being reflective and I can believe that the foam absorbs a lot of the rear wave.
I am interested in finding an answer, as I like to work with wood.
Maybe we need a new thread for this research so as not to hijack xrk's thread.
Help from moderators?
Myles
I think the rather thin foamcore in the vital midrange is fairly acoustically transparent vs plywood and may "de-Q cavity resonances vs stiffer and more acoustically "opaque" wood. You sure don't want a high Q front cavity resonance.
The smallest regular original Karlson was the little K8, tuned to about 95Hz. K12 tuned low 60.s, K15 upper 40's and X15 (and Acoustic control) 115BK, mid 50's.
K12 and K15 with the right drivers need no damping materials in their front chambers to sound good. I've only heard the little KR5 "Rocket" with its original table radio quality speaker. Carl had made that type with car coax and K-tube over the dome tweeter which would literally "pipe the highs out"
The clam/klam, asymmetric-projector variety of Karlson had the speaker placed further from the aperture than the Ultra-Fidelity series, and can have more "slap-echo" artifacts.
I'm curious as to effects of front cavity shape in K. I've heard effects in dispersion from reflector differences, and perhaps a bit leery about highly cupped chambers.
The smallest regular original Karlson was the little K8, tuned to about 95Hz. K12 tuned low 60.s, K15 upper 40's and X15 (and Acoustic control) 115BK, mid 50's.
K12 and K15 with the right drivers need no damping materials in their front chambers to sound good. I've only heard the little KR5 "Rocket" with its original table radio quality speaker. Carl had made that type with car coax and K-tube over the dome tweeter which would literally "pipe the highs out"
The clam/klam, asymmetric-projector variety of Karlson had the speaker placed further from the aperture than the Ultra-Fidelity series, and can have more "slap-echo" artifacts. I'm curious as to effects of front cavity shape in K. I've heard effects in dispersion from reflector differences, and perhaps a bit leery about highly cupped chambers.
Kay, an American instrument manufacturer, made bass and cellos using plywood, the back surface, hard maple, the front surface Spruce. The second ply was basswood, third was birch, fourth was basswood and the fifth most innermost ply was birch.
They sound pretty good, not the best instruments I've heard, but more consistent than solid wood instruments.
I don't think foam core will ever replace wood or plywood in instrument making ;^).
If a guitar or violin were made of foam core, it would sound even worse, IMO.
That said, when I first played the plywood speakers referenced way back in this thread they sounded tubby, with vocals sounding like from down a well. Experimenting with stuffing cured the problem. My test speakers from foam core were more forgiving. IMO, it’s too much work to make speakers out of foam core, except for the novelty or as a prototype.
Neil, can you summarize or did you post about the stuffing you ended up with in yours?
If I ever have the time (not likely) I'll make a version of both and see which I like best. Got my 3FE25-16's today. Let's cut some foamcore!
Looks like they worked out pretty well in BB ply even once stuffing was done correctly?
http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds-146.html#post4426583
http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds-146.html#post4426583
Multi Karlsonator (0.53)
A while ago, X commented the following when I asked about speakers for a First Watt M2: “You need more air displacement. As they say, there’s no replacement for displacement.”
Since then I've been toying with the idea to build a bigger speaker based on the Karsonator with dual FaitalPro 3FE25-16, because it has such a good sound. Then I thought, why not have four 0.53 K’s stacked on top of each other per side. That means 2 duals in series and 2 duals in parallel (still 8 Ohms). 8 drivers per channel.
Is there anything wrong with my logic? And if there is a better idea for budget M2 speakers, I’d like to hear about it.
It should be obvious that I'm in love with the sound of my 0.53 K's.
.
A while ago, X commented the following when I asked about speakers for a First Watt M2: “You need more air displacement. As they say, there’s no replacement for displacement.”
Since then I've been toying with the idea to build a bigger speaker based on the Karsonator with dual FaitalPro 3FE25-16, because it has such a good sound. Then I thought, why not have four 0.53 K’s stacked on top of each other per side. That means 2 duals in series and 2 duals in parallel (still 8 Ohms). 8 drivers per channel.
Is there anything wrong with my logic? And if there is a better idea for budget M2 speakers, I’d like to hear about it.
It should be obvious that I'm in love with the sound of my 0.53 K's.
.
You could make a larger karlsonator with 2x2 or 3x3 array of smaller drivers and then be able to wire them series-parallel for increased sensitivity. I think buried in this thread, I have a sim of a 3x3 Karlsonator using the Bose 901 drivers (1 Ohm ea and all in series) for quite an impressive speakers.
If you are interested in qnty 8 x 3FE25-16's at 8ohms, that works too. The cost of 8x$19 is getting up there with a more expensive larger driver, but the larger driver won't give you the highs of a small full range.
You could array multiple K boxes as you say, but that destroys the point source nature of the sound - and you may get phase anomalies and what is called "comb interference".
Better to stuff all 8 or 9 inside one larger cabinet with a single K aperture. Note that this has only been tried up to 2x2=4 drivers by a member (somewhere in this thread - from Korea). I have not done it myself so it may or may not work.
I can simulate for you a 3x3 3FE25-8 (good as it places 3 drives along centerline axis) for better physical alignment with aperture middle. This will give you a pretty sensitive 97dB speaker with 36% the cone area of a 15in woofer or equivalent bass of a 9in woofer, but with mids and highs of a 3.5in driver.
If you are interested in qnty 8 x 3FE25-16's at 8ohms, that works too. The cost of 8x$19 is getting up there with a more expensive larger driver, but the larger driver won't give you the highs of a small full range.
You could array multiple K boxes as you say, but that destroys the point source nature of the sound - and you may get phase anomalies and what is called "comb interference".
Better to stuff all 8 or 9 inside one larger cabinet with a single K aperture. Note that this has only been tried up to 2x2=4 drivers by a member (somewhere in this thread - from Korea). I have not done it myself so it may or may not work.
I can simulate for you a 3x3 3FE25-8 (good as it places 3 drives along centerline axis) for better physical alignment with aperture middle. This will give you a pretty sensitive 97dB speaker with 36% the cone area of a 15in woofer or equivalent bass of a 9in woofer, but with mids and highs of a 3.5in driver.
I'm getting Faital drivers at better prices from an audio shop in Italy.
This is exactly why I'm considering small drivers - to get the highs as well as mids and lows. A true full range speaker.
I must say I've been intrigued by these 25 driver Full Range line array speakers by Wesayso. No point source there and apparently they sound amazing.
If you have the time to do that, I'd be very grateful, X.
.
Attachments
X, what are the size increases for box and duct for dual PA-130 Karlsonators?
I have built single PA-130 and dual TC9D Karlsonators and single and dual PA-130 XKi's and much prefer the Karlsonators.
I know they will be fairly large but that doesn't matter. I'm sure there are several people who want to build these.
Thanks
I have built single PA-130 and dual TC9D Karlsonators and single and dual PA-130 XKi's and much prefer the Karlsonators.
I know they will be fairly large but that doesn't matter. I'm sure there are several people who want to build these.
Thanks
Let me run a sim for a box with pleasing dimensions. You can make one simply by scaling width and depth to double the volume but keep height the same. It will look a little more squat. It may be possible to extend the height a little and this gets deeper bass, but PA130-8 has limited bass extension since its Fs is rather high and suspension rather stiff.
Thank you, this will be my last PA130-8 build for a while. Next will be full size Karlsonators with maybe Beta 10CX's. I have the speakers for corner line arrays, and want to do something with the pair of BM-CX38 15's combined with Kappalite 3015's.
Busy times ahead. By the way I use those 7498 amps with the large white resistors. They have a great sound.
Busy times ahead. By the way I use those 7498 amps with the large white resistors. They have a great sound.
I think Beta10cx would be happy in a Karlsonator somewhat smaller than GregB's Karlsonator 12 and with somewhat higher tuning. The stock Karlsonator12 is tuned to 37Hz. Also, it might be good to look at Michael Chua's "Osprey" crossover for ideas as he's done extensive work with that coax to get good vocal reproduction. (I thought Eminence's suggested network was too muddy & "bland"
Osprey II - Eminence Beta 10CX 10" Coaxial - AmpsLab
Osprey II - Eminence Beta 10CX 10" Coaxial - AmpsLab
Last edited:
Thanks Freddi, I never replied to your post. I have no idea what I'm looking at in those graphs and tables. Do you mean it will work or will maybe work?
A friend and myself have also been looking at the FaitalPro 4" FR drivers: 4FE32/35.
Has anyone done a sim for them?
.
