|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
76.185.116.15
I got 4 new mystery 10" speakers (free so I can't complain).
Electrovoice 10's I think, but no listing for these 16ohm.
Probably have to bust out the old audio generator and see
if I can remember how measure T/S by added mass method.
Anyways, I was curious bout the Karlson cabinet. Allready
got an 8" concrete forming tube to try a quick and dirty
K-Tube for midbass shiggles... To hear it and , I dunno.
Don't intend to draw any firm conclusions based on total
first blind guess wild hair k-tubery experiment...
Supposing I throw two of these in a Karlson 15. Would you
think it better to align them vertically with the slot as
with DiApolleto, or widen the waveguide slightly and place
them side by side at the same distance from the end of the
k-coupler. Possibly abuse the gap between the 10's to make
a dipole k-coupler for the tweeter? Or a little K-Tube.
These will be used mostly for live music and portability...
If they work...
If the K's sound too weird, plan B is salvage the situation
with sealed box vertical DiApolleto arrangement, bullet in
the middle. Planning to cover the lows with a folded horn
sub anyway (also have 4 used but still good Eminence 12's,
57hz 97db as I recall. 80oz w. cast frames)
Trying not to buy anything I don't allready have, but wood.
And probably MDF is about all I could afford at the moment.
I'll upload a pic of the forming tube experiment after I
get the slot measured out and cut. Right now, I just got
the tube mounted to a wooden flange so I can bolt on the
speaker. And clearanced away from the cone edge movement.
The first 1/3 length of the big K-tube, slot or no slot?
What happens should I attempt to throttle and horn load
that 1st 1/3? These are some experiments I want to try.
Follow Ups:
I got all my measured pieces cut accurately
now, and ends mitered. Though I had to trim
the whole thing a tiny bit smaller than the
true K15 to make all my unequal pieces to
match each other exactly
I could not at this time afford another 4x8
of the matching birtch plywood to replace
my Klam blanks that got ruined in the first
sawing. But I was able to buy a smaller Luan
2x4(ft) with aproximately the same number of
internal laminations beneath the veneer (~11)
Luan Klam blanks will have to do for now.
I have two matching baffles. One to cut holes
for my 10+Tweet+10. Other "insurance policy"
to hole out for standard 15" mounting option.
Or use in the next Karlson, if I like this one.
I have not yet routed those holes, nor rounded
any edges, nor tapered the Klams... I plan to
mock up the assembly (without gluing) tonite.
I got a bunch of them Kreg - Pocket Hole screw
thingies been wanting an excuse to try anyhow.
Pics soon as I got something what half looks
like a speaker to show.
hi - -I called my buddy Carl and he reminded me of Karlson's firzt patent with asymmetric slot
go side by side and possibly two modules per channel - C's thoughts were narrow side-side dimension would help.
I"m not feeling well so don't have much gusto. 1.25 CF per woofer rear might be ok - it could be built as one bulky cabinet. there should be a rear lowpass choke to clean up the rear wave before exiting out the vent
Fig 2 of 1951 patent
two modules side by side
one of Wayne's old K10 testboxes
approximate dimensions of that coupler
Don't run out and build this now... Its only an experiment.
And at this point sounds like it still needs serious tuning.
So far I discovered (by totally unscientific observation):
Driver is much louder in MidBass with the Coupler.
Top end sparkle drops out some notches I think.
The top end sounds best with the coupler about 2
inch gap suspended above the cone??? Go figure...
Blocking the lower 1/3 of the slot definately
does not help anything. The full slot is better.
Prying the slot wider seems to help, may widen
some more, as I conservatively cut only 1/2 the
circumferance at the big end of the exponential.
Easier than adding missing material back.
The tube is directional (up and slightly forward)
unless you add the angled piece inside, it does
not radiate well toward the listener. The angled
piece helps immensely, and I can see why Karlson
and Poppe both did this. How do other tubes live
without?
Anyone know this driver? I am almost sure its an
EV10M, but no listing for any such built to 16ohm.
cool tube - nice looking driver - - K-couplers R krazy and on my 42" tall k18 blocking the narrow upper slit kills some of its speed.
HF lobe in a klam or K-tube go pretty much straight down the tube
here's Karlson's idea of dispersion of KR5 rocket when mounted with base to wall to for the "asymmetric projector" - - Karlson in Acoustic Transduces 1 & 2 showed "protuberances" in some klams and k-microphones
snippet of Karlson's 1961 letter to Poppe
heres rough dims of Poppe's vertical rocket for 6"x9" - I think he kept the nose open on the MIT test K-coupler and others figuring the wave hadn't fully reached room Z - - (John Karlson didn't have the nose gap in his klams)
for something shorter as a 10" driver toy to try, here's a klam 10 by Carl -= IIRC its rear chamber was optimized for old Eminence B102
approximate dimensions
k's work well in ~K15 size
Musta been something weird in that Hot and Sour soup.
Anyways, here's what happened to the cup...
I was thinking since I will probably be firing crossways
thru the main slot of a K15 type. That the best whizzer
for me might not be one that projects straight forward.
Whatever bent logic led me to try this, its not having
any effect whatsoever that I can tell. Not coupled to
the cone with any adhesive other than 9.8M/S^2 gravity.
And the foam hardly weighs anything. Not sure I care
enough about this experiment to try gluing it down or
even doublesided tape.
It definately isn't causing any problems. It just isn't
adding anything to justify why it is there. Perhaps the
geometry I have chosen doesn't favor forcing sound thru
the whizzer's K slot? Therefore doesn't do much at all.
If I add an angled piece to make the koupler work, this
probably gets way beyond the mass I want for a whizzer...
I may try it anyway. Absurd doesn't seem to be much of
a barrier with this sort of experimentation.
Now this works! Well, its doing something... Mostly good I think.
Cymbals and guitar are far more alive.I got better results as I bent the radial klams down to almost
touch the dust cap. The speaker cone and dust cap give a shape
that persuades the waves out the slots. I don't have to add any
moving mass that wasn't already there.I suppose this could also be tried with four or 5 petal radial
klams. Driver with big round dust cap is probably a requirement
to give the radial kavitys a Karlson shape.To be fair, I have not tried a simple hole of the same throat
area. It could be nothing more magic than that... More later.
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: