XKi RS100-4 in Stereo
I finished the stereo pair for the RS100-4 today. They sound great - even with no EQ, very enjoyable. Astonishing bass extension and impact. Definitely a keeper and highly recommended build - super easy 2 hr construction and 1 sheet of foam core. This is one of those speakers where people will ask you where the sub woofer is hidden. I am really enjoying listening to them. Smaller than the 0.4x Karlsonator, yet deeper bass extension similar to the 0.53x.
I finished the stereo pair for the RS100-4 today. They sound great - even with no EQ, very enjoyable. Astonishing bass extension and impact. Definitely a keeper and highly recommended build - super easy 2 hr construction and 1 sheet of foam core. This is one of those speakers where people will ask you where the sub woofer is hidden. I am really enjoying listening to them. Smaller than the 0.4x Karlsonator, yet deeper bass extension similar to the 0.53x.
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very nice on the measurements and their looks ! how does that paper cone sound in contrast to the aluminum?
Thanks guys, it's a fun little speaker. The paper sounds less sibilant on vocals but has slightly less bass punch. I probably prefer the paper for most music but for now the Al cones stay on this to free the paper cones for other projects.
XKi as a compact sub woofer
Over in the sub woofer forum I have a design using the XKi with dual vents and dual Alpine SWS 10D4 drivers for a 125dB 35Hz sub with 90 liter net active volume.
http://www.diyaudio.com/forums/subwoofers/259509-new-sub-design-constricted-transflex-simple-build-series-tuned-6th-order-108.html#post4223469
Those are some very cost effective drivers and with a Vas of 25liters is perfect for a compact XKi implementation that is not xmax limited (power and vent compression limited instead).
Over in the sub woofer forum I have a design using the XKi with dual vents and dual Alpine SWS 10D4 drivers for a 125dB 35Hz sub with 90 liter net active volume.
http://www.diyaudio.com/forums/subwoofers/259509-new-sub-design-constricted-transflex-simple-build-series-tuned-6th-order-108.html#post4223469
Those are some very cost effective drivers and with a Vas of 25liters is perfect for a compact XKi implementation that is not xmax limited (power and vent compression limited instead).
I should not be but am surprised that Mathew Morgan, and XRK, (and others I'd guess) have created something not known about (or not well known) a new speaker alignment. This is big.
XRK, how reliable is that vendor Aliexpress? Am thinking of pulling the trigger on a purchase of that bluetooth 3116 amp. Have a couple, a 3116 amp, a 2 and a 2.1 amp, but bluetooth for streaming from a mobile phone would be great.
I have had good luck with Aliexpress. They are slow but trustworthy. One time a shipment did not arrive and they credited my card back no hassle. I have bought 4 amps each one takes 3weeks to ship. Very inexpensive and great deals.
hi XRK - - any further thoughts on the Beta10cx XKi vents? - is it a viable XKi driver? I still have unused P-Audio SN10C coax which need a Karlson-type. (Jesse cut the 0.65x K15 for Beta10cx and I'll probably try some 8s in those) Beta 8 XKi are slated to be built.
XKi Subwoofer with dual TB W5-876SE's
This was a prototype of a subwoofer using the XKi alignment with a couple of 5 inch PE buyout W5-876SE 16ohm sub drivers.
The design ended up as 18 liters on the rear and 3 liters on the front chamber with dual 7in wide x 0.6in high x 17in long wraparound vents. The front "vent" is a K-aperture with equivalent area to a 7in dia circle. The design f3 was 45Hz, with intended application as a corner loaded sub to I wanted a down-slanted bass shelf to compensate for room gain. Predicted cone motion for regular listening levels circa 90dB was less than 1.5mm (5 mm xmax) to keep distortion low.
I implemented the build in regular dollar store 3/16in thick foam core with a sandwich of FC and double-wall cardboard for the driver mount baffle and K-aperture. Only hot melt glue is used throughout. Otherwise, copious bracing with FC is used throughout. The box was very strong and vibrated a lot less than many of my other FC builds due to lots of bracing.
Here are the photos of the build - turned out to be a regular 3d sculpture with curve vent entrances and exits to reduce turbulence and allow one piece wraparound baffle/vent construction (Grandcalmar's construction idea):
Here is a nearfield measurement 2 inches away from exit plane to remove room effects - as you can see the bass corner ended up near 35Hz - about 10Hz lower than I expected. So there is something I am missing in the model - a correction for the narrow aspect ratio slot vent (empirically the factor is 0.67x to be applied to CSA to get freq predicted to match):
How does it sound? Only had a chance to listen to a couple of tracks with it as a FAST using an RS100-4 XKi on the top. Sounds very nice - digs deeper than I would have guessed possible for a couple of 5 in drivers. The SPL, is not huge though - about 88 dB at 1m and 2.83v for 40Hz because it is tuned too low. If the vents were shortened to get f3 back to ~50Hz, the SPL's would be quite a bit higher.
I will report back with more data when I have some time.
This was a prototype of a subwoofer using the XKi alignment with a couple of 5 inch PE buyout W5-876SE 16ohm sub drivers.
The design ended up as 18 liters on the rear and 3 liters on the front chamber with dual 7in wide x 0.6in high x 17in long wraparound vents. The front "vent" is a K-aperture with equivalent area to a 7in dia circle. The design f3 was 45Hz, with intended application as a corner loaded sub to I wanted a down-slanted bass shelf to compensate for room gain. Predicted cone motion for regular listening levels circa 90dB was less than 1.5mm (5 mm xmax) to keep distortion low.
I implemented the build in regular dollar store 3/16in thick foam core with a sandwich of FC and double-wall cardboard for the driver mount baffle and K-aperture. Only hot melt glue is used throughout. Otherwise, copious bracing with FC is used throughout. The box was very strong and vibrated a lot less than many of my other FC builds due to lots of bracing.
Here are the photos of the build - turned out to be a regular 3d sculpture with curve vent entrances and exits to reduce turbulence and allow one piece wraparound baffle/vent construction (Grandcalmar's construction idea):
Here is a nearfield measurement 2 inches away from exit plane to remove room effects - as you can see the bass corner ended up near 35Hz - about 10Hz lower than I expected. So there is something I am missing in the model - a correction for the narrow aspect ratio slot vent (empirically the factor is 0.67x to be applied to CSA to get freq predicted to match):
How does it sound? Only had a chance to listen to a couple of tracks with it as a FAST using an RS100-4 XKi on the top. Sounds very nice - digs deeper than I would have guessed possible for a couple of 5 in drivers. The SPL, is not huge though - about 88 dB at 1m and 2.83v for 40Hz because it is tuned too low. If the vents were shortened to get f3 back to ~50Hz, the SPL's would be quite a bit higher.
I will report back with more data when I have some time.
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it looks amazing & "deco" in white foamboard - - I've had R-J and other slot vents tune lower than what Augspurger's "ventwrk" routine would predict. Is there a non-destructive way to re-tune this prototype?
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Give me a few days until I get my main computer back and I will work this. I think it should be possible to get it to work for you. What is your max allowable box volume and what bass extension do you want?
re:XKi for Beta10cx - I want a fair amount of cone control vs LF extension - it would be nice to keep external bulk to no larger than classic K12 (~3.3 cubic feet) an F10 of 40 or higher would be really good. I may have to use P-Audio SN10C as my current Beta10cx are slated for the 0.65X K15.
for a traditional "X15" style K of some sort with woofer and K-tube, Parts Express has a little 10" woofer which looks suitable
Thanks for the kind words Matthew Morgan J. You should try FC builds sometime - cheap and fast.
for a traditional "X15" style K of some sort with woofer and K-tube, Parts Express has a little 10" woofer which looks suitable
This looks like it can work, but Vas is a bit big - might be a rather large box. You may want to look at some of the car audio subs like the Alpine SWS 10D4.
Another possible driver for XKi might be the very cost effective Infinity 1260W sub driver for $70. Those seem to work well in 6th order band pass designs.