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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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).
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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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.
Truly a work of art , gorgeous FC build X !
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.