Luigi asked how people got the edges smooth. I use sheetrock abrasive screen. It's a 4x8" piece of window screen dipped in abrasive. It comes in a 3 or 4 piece pack, and is quite inexpensive, at Lowes, HD or Walmart. It makes fast work of smoothing out the edges, works on wood, too, and lasts forever when used on foamcore. I believe it's 240 grit.
I made these videos a while back and forgot they were not published publicly. You can listen to my XKi with W5-2143’s here:
XKi W5-2143 Speaker Test - YouTube
XKi W5-2143 speaker - YouTube
XKi W5-2143 Speaker Test - YouTube
XKi W5-2143 speaker - YouTube
EddieT,
I used hot glue with them in speaker boxes. E6000 works well, too. Pva works well if you are not going to subject them to much stress, as it doesn't soak in to the sponge. I made a big mat of the small 4x6" ones to put behind a DML, and used pva, and they tended to pop apart even several weeks later if I flexed them too strongly. I put the mat inside folded over drapes, and that worked well.
I used hot glue with them in speaker boxes. E6000 works well, too. Pva works well if you are not going to subject them to much stress, as it doesn't soak in to the sponge. I made a big mat of the small 4x6" ones to put behind a DML, and used pva, and they tended to pop apart even several weeks later if I flexed them too strongly. I put the mat inside folded over drapes, and that worked well.
what XKi might make a punchy helper woofer to go underneath an 8 inch K-midrange and K-tube ? The midrange box is 11" wide by 12" high and will sport a B&C 8PL21, That K-tube holder is for a cheap and hopefully cheerful 13lb 1.5" format compression driver (or a small K-tube and DE250, etc.)
I want the 3-way ensemble to do a nice job on drumkit.
That little midrange box by a good friend is stiff 1/2" plywood with 3/4" plywood wings. There is another set of wings for a tighter aperture.
I think the lack of cavity volume above the driver and shallow 20 degree wedge cavity will result in a reasonably neutral arrangement.
shamefully, I need to order mounting screws.
I want the 3-way ensemble to do a nice job on drumkit.
That little midrange box by a good friend is stiff 1/2" plywood with 3/4" plywood wings. There is another set of wings for a tighter aperture.
I think the lack of cavity volume above the driver and shallow 20 degree wedge cavity will result in a reasonably neutral arrangement.
shamefully, I need to order mounting screws.
My melamine foam pads arrived a week or so ago (6 weeks from China). I am searching for some music to used for subjective evaluation when I get around to experienting. I currently have some flooring underlayment felt lining in place. As for music Urbie Green's trombone sounds great as is. I knew (and worked with) Urbie's younger sister and her husband in the mid 80s but that was before youtube so I am just now trying his music. He sounds great on the PA130-8s.
(good enough mix (kinda -..) - don't like it musically - Cissy Strut or even some MM&W more my liking for groove based cut)
That old Feelin' Jack Sheldon - 17dB or more on the old dynamic range meter
That Old Feeling - Jack Sheldon Septet - YouTube
I Aint' Got Nobody - Preservation Hall Jazz Band- always used this for demo
I Ain't Got Nobody - YouTube
a few seconds of acoustic guitar X-Y miced-ed w/o feects
How to Record Acoustic Guitar with TWO Mics - YouTube
(early, 1980 digital) - sax thin and hard- but Cleanhead had many versions and his voice always dynamic.
Cherry Red - YouTube
(fair anallog)
Cherry Red - YouTube
That old Feelin' Jack Sheldon - 17dB or more on the old dynamic range meter
That Old Feeling - Jack Sheldon Septet - YouTube
I Aint' Got Nobody - Preservation Hall Jazz Band- always used this for demo
I Ain't Got Nobody - YouTube
a few seconds of acoustic guitar X-Y miced-ed w/o feects
How to Record Acoustic Guitar with TWO Mics - YouTube
(early, 1980 digital) - sax thin and hard- but Cleanhead had many versions and his voice always dynamic.
Cherry Red - YouTube
(fair anallog)
Cherry Red - YouTube
In a sense, most of Karlson's original designs were scaled from K15. In the January 1954 issues of Radio and Television News, he warned against scaling K15 by 0.8 (12/15) and at the HiFi fair of fall 1954 came out with the first Karlson Twelve (aka at the time as "Karlsonette" as the 8 inch model had another year to appear)
In reality a 0.8 scale K15 can work pretty well, but is a bit larger than the K12 series. Also, the front shelf may be shortened in a 0.8 scale K12 as that feature tends to deflect some highs from the upper regions of the front chamber.
The Karlsonette had a perpendicular port board. Also it had a unique feature of a movable 3-position "bar" on the inside of the back panel which was adjacent to the rear shelf. This made for subtle tuning adjustments of the chambers and the kind of thing to tune subjectively with drum transients.
Subsequent K12 used a 10 degree forwards tilt port board with distributive slit or hole array port. The full width rear shelf was split for most of the K12 series (that made a great rear panel brace) but made a comeback in a K12 kit enclosure.
Karlson with the regular lineup of K12, K8 and the X15 cabinet never used the front shelf again but suspect it was used in Karlson's 18 inch "console"
K12 are tuned around 62Hz small signal.
The distributed slit vent chokes up and produces high vent velocities and harmonic noise on sine input around tuning. With music transients, that doesn't seem to be much of a worry (-I might prefer a single vent for higher input power.)
With a higher Q speaker such as EV Wolverine, a K12 might sound overly warm mushy. With something like Kappa 12A, it will GRAB one's attention and beat some folded horn for focus and impact (not as loud but better pitch focus) - plus 3mm excursion (one way) speakers with good motor.will hold down 200 watt input peaks.
GragB's Karlsonator12 offset driver K-variant is tuned @37Hz way down from a K12 and should go as low as most K15 setups.
A K-tube with compression driver is a great way to have treble vs horn.. (See ReinoutDV's K-tube plus Field Coil thread in the Multi-Ways forum) XRK971's work with 3 inch drivers shows speakers of that size range can exhibit very wide horizontal dispersion - so a dedicated K- "Kone" tweeter is possible.
I think a little 6 inch K15 scaled by XRK971 for a particular driver plus a sub would make a nice system. The Karlsonator6 too as was very good with a modified Fostex FE164 and also with LCao F6. (the Fostex wins for attack as has a stronger motor)
One thing I want to emphasize, Karlson's originals still hold a place. I do soon need
an XKi bass module to go with my K8 midrange and K-tube setup.
In reality a 0.8 scale K15 can work pretty well, but is a bit larger than the K12 series. Also, the front shelf may be shortened in a 0.8 scale K12 as that feature tends to deflect some highs from the upper regions of the front chamber.
The Karlsonette had a perpendicular port board. Also it had a unique feature of a movable 3-position "bar" on the inside of the back panel which was adjacent to the rear shelf. This made for subtle tuning adjustments of the chambers and the kind of thing to tune subjectively with drum transients.
Subsequent K12 used a 10 degree forwards tilt port board with distributive slit or hole array port. The full width rear shelf was split for most of the K12 series (that made a great rear panel brace) but made a comeback in a K12 kit enclosure.
Karlson with the regular lineup of K12, K8 and the X15 cabinet never used the front shelf again but suspect it was used in Karlson's 18 inch "console"
K12 are tuned around 62Hz small signal.
The distributed slit vent chokes up and produces high vent velocities and harmonic noise on sine input around tuning. With music transients, that doesn't seem to be much of a worry (-I might prefer a single vent for higher input power.)
With a higher Q speaker such as EV Wolverine, a K12 might sound overly warm mushy. With something like Kappa 12A, it will GRAB one's attention and beat some folded horn for focus and impact (not as loud but better pitch focus) - plus 3mm excursion (one way) speakers with good motor.will hold down 200 watt input peaks.
GragB's Karlsonator12 offset driver K-variant is tuned @37Hz way down from a K12 and should go as low as most K15 setups.
A K-tube with compression driver is a great way to have treble vs horn.. (See ReinoutDV's K-tube plus Field Coil thread in the Multi-Ways forum) XRK971's work with 3 inch drivers shows speakers of that size range can exhibit very wide horizontal dispersion - so a dedicated K- "Kone" tweeter is possible.
I think a little 6 inch K15 scaled by XRK971 for a particular driver plus a sub would make a nice system. The Karlsonator6 too as was very good with a modified Fostex FE164 and also with LCao F6. (the Fostex wins for attack as has a stronger motor)
One thing I want to emphasize, Karlson's originals still hold a place. I do soon need
an XKi bass module to go with my K8 midrange and K-tube setup.
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I already made the Mini Karlsonator (0.53X) with the PA130-8 and really liked how they turned out. I am interested in pushing the design a bit further and doing a Karlson inspired FAST/WAW 2-way. I was thinking something like a 3FE22 in a 0.4x scaled enclosure (or dual 3FE22's in a 0.53x if I need the efficiency) and two 8" woofers in a Karlsonator 10 scaled enclosure. Maybe even a XKi enclosure for the dual 8's as they appear to favor low end output. Target crossover would be 200-500hz with a simple first order network.
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