You mean acoustical phase as measured with the mic and not the phase measured with an impedance sweep? I can get that info it will take some time to dig it up b
XRK, did you ever get AKABAK working again? Would like an optimized rendering for a Eminence CX10. I have Nomex honeycomb core with 1/16" skin shiny finish graphite skin ready for this (1" and 1.5" resulting thickness) in 20" X 20" panels.
I recovered all my Akabak files but the virtual machine it was running on is gone. Easiest for me to just use an old 32 bit laptop I have to do this but means I can't take with all the time. When I get a chance I will get a CX10 design for you.
like also to see a Beta10cx design as that would be fun to compare with 0.65X K15 and Karlsonator 12 (both which also can run Beta10cx)
HI noob hear. I jumped the gun and ordered the fe83 fountek for the xki build before reading to the end. I then read where it sounded terrible. No attempt to adjust or resize the box/port to correct terribleness? I would love to try this type to compare to the Zaph HIvi best 3", and his bargain mini and the OS builds I have done. The window curtain front face amplifies the output? 6th order bandpass? And foam core quick enclosures is my kind of instant gratificationSo is fe83 build dead? Like small size big clean sound junky here.thx
It might sound better in foam core than plywood - easy enough to make that it's not a big deal of it doesn't work. I think the Fountek has been noted as sounding harsh and tinny in other projects as well. Get the RS100-4 if you can - that driver in an XKi sounds great with rich full bass.
hi xrk971 - in another thread, for a speaker mounted under an outdoor A frame structure, there was a suggestion of using a klam. I grabbed a BG20 and put it in a copy of the Weiss "Rocket" klam8. The results are too rough. Some klam can sound pretty good but not that one with that driver up close. Anyhow, what do you think of using the Beta8cx XKi with a BG20? is BG20's vas too high? - it might play in a K8 like Art's dad's cabinet which had large slot vents but K8 generally are good only to around 100Hz or so.
walters may have some ideas as IIRC he uses PA130 in klams. Maybe an XKi for PA130 would make a nice little speaker.
walters may have some ideas as IIRC he uses PA130 in klams. Maybe an XKi for PA130 would make a nice little speaker.
I can run a sim of an XKi with BG20 and see. I think XKi likes smaller Vas drivers and low Qts. It's all about motor strength to squeeze the air through that 6th order Bandpass feedback duct and front vent.
I could load BG20 into a rough K8 copy, seal vents and check "Qtc"- maybe fast flare (almost "V") wings like Carl suggested for the outer boundary of the "SK8" coupler
XKi for Beta 8CX tuned 70Hz
Freddi,
Per your request to hit 70Hz. This is a 17 liter box (internal volume) with 2/3rd volume in back chamber and 1/3 volume in front chamber with 10in wide x 1in tall x 12.25in long vent. Make the K-aperture about 60 sq inches (12 in high x 10 in wide). You can get about 108dB at 20volts for xmax - xlimit is much higher. -3dB is 67Hz and I use a 57Hz -24dB HPF. Note that this is a simplified sim without the effects of the K-aperture and mixed front radiator. I think in reality, the bandwidth should be broader and smoother.
Here is SPL at xmax:
Here is cone displacement at 20 volts for xmax with HPF:
Here is vent velocity at xmax:
Freddi,
Per your request to hit 70Hz. This is a 17 liter box (internal volume) with 2/3rd volume in back chamber and 1/3 volume in front chamber with 10in wide x 1in tall x 12.25in long vent. Make the K-aperture about 60 sq inches (12 in high x 10 in wide). You can get about 108dB at 20volts for xmax - xlimit is much higher. -3dB is 67Hz and I use a 57Hz -24dB HPF. Note that this is a simplified sim without the effects of the K-aperture and mixed front radiator. I think in reality, the bandwidth should be broader and smoother.
Here is SPL at xmax:
Here is cone displacement at 20 volts for xmax with HPF:
Here is vent velocity at xmax:
Attachments
if it follows the sim, then will have somewhat better LF extension than some K12, so would expect it to sound reasonably well balanced on most music without a subwoofer. These should work nice on tripods and in 2.1 mode with extension to maybe 40Hz solid to keep the 3-piece system light and compact.
IIRC the drawing below was for an ~60Hz version with Beta8cx
IIRC the drawing below was for an ~60Hz version with Beta8cx
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Yes this drawing can be modified with a 12.25 in long vent that is 1.0 in tall instead of 0.75in for 70Hz version. The depth of the front chamber has to be adjusted so volume is 1/3 of total 17liters and back chamber is 2/3 of 17 liters.
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hey X - IIRC, during your Beta8cx XKi development, vent area and length were reduced from initial values to reduce a cancellation - would that same problem occur with the 1" high x 10"W x 12"L vent? Did you pick the large area vent as a practical tradeoff for large signal efficiency?
not sure about the depth adjustment - what was the front volume in the above - 4 liter? Due to the large magnets,
its not real practical to increase the baffle angle by much - how would you make the adjustment so the front
has around 0.2 cubic foot airspace?
not sure about the depth adjustment - what was the front volume in the above - 4 liter? Due to the large magnets,
its not real practical to increase the baffle angle by much - how would you make the adjustment so the front
has around 0.2 cubic foot airspace?
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Freddi,
Yes, I was concerned with the possible vent cancellation thus I made the vent area larger to reduce the velocity and the length is shorter than my initial version. This was in an effort to preserve efficiency and give you an fb of 70Hz. The front chamber volume that I suggest is 0.2 cu ft as 1/3 of 17 liters is 0.20 cu ft. Are you concerned that the rear chamber isn't big enough for the basket and CD magnet? Have to sketch out the chamber based on dinensions and volumes to know for sure.
XKi for B&C 15TBX
Freddi,
I recall you have a B&C 15TBX lying around... Here is a sim for an XKi as a thumpin' sub woofer. 5.3 cu ft total internal volume with usual 1/3 front and 2/3 rear volume distribution, with 18in wide x 2.5in high x 24in long vent, K-aperture is about 175 sq in (24in high x 15 in wide). 120dB SPL at xmax with 58 volts and achieves 33Hz at -3dB. Use 30.5Hz -24dB BW HPF.
Freddi,
I recall you have a B&C 15TBX lying around... Here is a sim for an XKi as a thumpin' sub woofer. 5.3 cu ft total internal volume with usual 1/3 front and 2/3 rear volume distribution, with 18in wide x 2.5in high x 24in long vent, K-aperture is about 175 sq in (24in high x 15 in wide). 120dB SPL at xmax with 58 volts and achieves 33Hz at -3dB. Use 30.5Hz -24dB BW HPF.
Attachments
on the Beta8cx - a little concerned to fit - would probably use the excellent D280Ti PRV as have two sets (they changed style IIRC from the first offered at PE) 5.3 cubic feet for 15TBX40 is pretty good - K15's two chambers seem like 2.2 front and 3.6 loaded rear so this would be in direct comparison to a K15. 15TBX as a direct radiator sounds kinda power hungry as its midrange is around 5-6dB less than a 15 with mms in the 50-60 gram class.
Let me sketch it out to make sure it fits. On my XKi I used 25% volume in front chamber so there was a little more there.
hey X - one of these days it would be nice to have a K of some sort for my old Panasonic Metal FA pair - they really need a helper tweeter so perhaps a K-tube driven by a hot dome might work
that's a BetsyK next to the Panasonic - qts is moderate on the Pana so its not so horn friendly.
that's a BetsyK next to the Panasonic - qts is moderate on the Pana so its not so horn friendly.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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