It would be fun to come up with some good small K which are better than this one shown loaded with Delta Pro8A (it also ran W8-1772, FE206 and AN8 fullrange drivers) I think a 10" with strong motor is aboout the smallest driver which can get most of a drumkit's mounted tom sound. But perhaps this little 8 with stub and K-tube could do well with a helper woofer.
I have two other sets of aperture wings for this coupler. One YouTube comment says its wrong to have
the straight lines. IMO that's quite subjective and sometimes an "open" aperture may work better -
it can affect system tuning a bit depending upon where the port is relative to the tight part of the aperture.
a port located like K15 position can put a lot of pressure on the wings. A sealed back chamber K, not much.
likewise, the klam with driver buried deep and close proximity to the narriow portion of the wings can excert
a lot of pressure - I've see deflections of 0.6" p-p with wings in a klam18 (time for bracing)
YouTube
I have two other sets of aperture wings for this coupler. One YouTube comment says its wrong to have
the straight lines. IMO that's quite subjective and sometimes an "open" aperture may work better -
it can affect system tuning a bit depending upon where the port is relative to the tight part of the aperture.
a port located like K15 position can put a lot of pressure on the wings. A sealed back chamber K, not much.
likewise, the klam with driver buried deep and close proximity to the narriow portion of the wings can excert
a lot of pressure - I've see deflections of 0.6" p-p with wings in a klam18 (time for bracing)
YouTube
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Since the model says a stub of 10.5" is ok, can we assume the small unslotted portion of the front panel effectively lenghtens that stub "a bit" ? If so, should the gap between the stub's front edge and inside of the front panel be made the height of the stub opening - ?
Freddi,
Yessir, you are correct, with the open end of the Freddi-Mod stub being so close to the unslotted top of the front panel it will indeed add to the effective length of the Freddi-Mod stub .... In order to compensate we can bring the closed end of the Freddi-Mod stub forward by just enough to get our effective stub length back around 27cm -ish . At least that is one solution that comes to mind ..
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They both look good , it is close, splitting hairs here but as Bp1Fan said the 26.7cm does look better ..
can you model a 45 degree deflector at the un slotted top of the front panel as this would direct the air in the freddi-mod stub into the front chanber and give it less 'ping pong" back and forth on its own.
hi Moray - -like "this" and that size ? - or would it be larger ?
hey Matthew -
I need some dims on this thing to make sense and submit to the cutter.
I've not yet heard from him so don't know if he started the XKi or not.
What should we set the inside dimensions at so all fits and works (hopefully!!!) in harmony?
Will 1/2"BB be sufficient? - (with good bracing - I think so)
What's a good lowpass filter for Delta10a so it may mate with a K-tube on top of the cabinet?
(IIRC, it has to counter a ~6dB/octave rise of Delta10a staring around 1K or so)
hey Matthew -
I need some dims on this thing to make sense and submit to the cutter.
I've not yet heard from him so don't know if he started the XKi or not.
What should we set the inside dimensions at so all fits and works (hopefully!!!) in harmony?
Will 1/2"BB be sufficient? - (with good bracing - I think so)
What's a good lowpass filter for Delta10a so it may mate with a K-tube on top of the cabinet?
(IIRC, it has to counter a ~6dB/octave rise of Delta10a staring around 1K or so)
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hi Moray - -like "this" and that size ? - or would it be larger ?
hey Matthew -
I need some dims on this thing to make sense and submit to the cutter.
I've not yet heard from him so don't know if he started the XKi or not.
What should we set the inside dimensions at so all fits and works (hopefully!!!) in harmony?
Will 1/2"BB be sufficient? - (with good bracing - I think so)
What's a good lowpass filter for Delta10a so it may mate with a K-tube on top of the cabinet?
(IIRC, it has to counter a ~6dB/octave rise of Delta10a staring around 1K or so)
Hey Fred that's more or less what I had in mind but looking at it though I think I might adjust it so the re direction parallels the reflector section above the woofer that way it might provide more pressure on the woofer which is what you want I think. any reflector is going to minimize the stub just going into a back and forth reflection.
Freddi ,
Outer dimensions of 17.5" height by 13" width by 11.5" depth give us the ideal (26cm or 27cm -ish) Freddi-mod stub length if we include the 90 degree turn at the front of the cabinet as part of the stub's length ....
The innards all fit and work in harmony..
Alternately if you wanted to make this cabinet capable of accepting a 12" driver as well then we could add an inch to the width and reduce our height down to 16.25" (outer).
Either way works for a 10" driver like the Delta 10a
Yes, 1/2" BB works .. Just be sure to use plenty of internal bracing..
Behind a K-Slot & aperture i suspect that the Delta 10a's rising upper midrange response will be leveled off somewhat and may very well be good out to as high as 2800hz (based on Eminence's published curve for that model) .. ...
The K-slot should help to make your horizontal coverage more consistent (alleviates the beaming to some extent, at least that was my experience with the K-slot when I experimented with it) ..
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Oh Matthew - I'll read your comments in a minute from this posting
the option of a 12" driver is interesting and would be great to try vs Delta10a.
here's what I saw but am not sure if correct - my left eye points to the left
and wobbles
I came up with about 12.5" D x 12" W x 20" high inside dims - the stub
would be too long the way I drew it.
Wish I could make a reasonably accurate drawing based upon your description.
for 12" I've Comonwealth12 (no xmax), Peavey SC12 (Qt too high), Pym1298 (same as Kappa12a)
the option of a 12" driver is interesting and would be great to try vs Delta10a.
here's what I saw but am not sure if correct - my left eye points to the left
and wobbles
I came up with about 12.5" D x 12" W x 20" high inside dims - the stub
would be too long the way I drew it.
Wish I could make a reasonably accurate drawing based upon your description.
for 12" I've Comonwealth12 (no xmax), Peavey SC12 (Qt too high), Pym1298 (same as Kappa12a)
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Using outer dimensions of 17.5" height by 13" width by 11.5" depth, how far back will the top edge of the baffle sit from the inside of the front and how much gap from the inside front to the stub tunnel's front edge?
alternately - how deep is the tunnel now? + how deep is the front cavity at the top edge of the baffle?
- the baffle's height might need to be a bit larger to accomodate a 12. Would it then be 13x13?
this is a really tiny box for sure ! - I need to put a crossover board in it too.
alternately - how deep is the tunnel now? + how deep is the front cavity at the top edge of the baffle?
- the baffle's height might need to be a bit larger to accomodate a 12. Would it then be 13x13?
this is a really tiny box for sure ! - I need to put a crossover board in it too.
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yeah - if cutter's time permits. (at my age, being alive til then is tricky enough) Whether the cavity shape and model are favorable = "a known unknown" . . . .
btw - II like Karlson's K12. With Kappa12 plus K-tube on one of the late Rudy Rosa's snth cuts, its got a faster
and more powerful "grab" than my Klipschorns - of course the balance and presentation are quite different but the
damn little box seems to connect well with the air between it and the listener. I'd take a K12 over my Peavey FH1
any day for a lot of music - but the crappy FH1/La Scala type can be fun with good midhorn + tweeter on AC/DC
at near concert levels.
btw - II like Karlson's K12. With Kappa12 plus K-tube on one of the late Rudy Rosa's snth cuts, its got a faster
and more powerful "grab" than my Klipschorns - of course the balance and presentation are quite different but the
damn little box seems to connect well with the air between it and the listener. I'd take a K12 over my Peavey FH1
any day for a lot of music - but the crappy FH1/La Scala type can be fun with good midhorn + tweeter on AC/DC
at near concert levels.
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Freddi,
You need to open that gap in front up to 2" in both cases ..
Minimal width would be 13.5" to be safe (because 12" drivers typically have frame diameters that are a little bit larger than 12") .... In that case you just subtract a little from the height in order to maintain our internal volume .
For example: If we wanted to go a little further with that then 16.25" x 14" wide x 11.25" also works
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