I finally found an affordable source for foam board and was about to order a pair of 3fe25 for the 0.4 karlsonators when I found this thread.
It does not look more difficult to build and might give me some more bass extension. Would this work with the 3fe25 instead of the dayton rs100-4? I know the 3fe22 with its lower Qts works, but it's double the price.
It does not look more difficult to build and might give me some more bass extension. Would this work with the 3fe25 instead of the dayton rs100-4? I know the 3fe22 with its lower Qts works, but it's double the price.
I would suggest you stick with the 3FE25 and 0.4x K'nator as that speaker reaches a good deep bass for its size. You won't get deeper bass with the 3FE22 on the XKi. The RS100-4 will get deeper bass as shown in this thread but may have more mid bass coloration.
Oh the fun that can be had for a dollar. I picked up a sheet of foam core at Dollar Tree and proceeded to modify what I thought were K4s scaled from a 1955 K12 with shelf. When i got into the project I found that they contained AD5080/X8s which are 5". So my boxes are .42 quasi scaled K12s. I added a duct to the original vent point as suggested in post #7. The only test is a subjective comparison to its unmodified twin. It did improve the sound but I think the 5080s are midrange drivers.
The inside view pic shows duct opening at top rear and the messy area in the middle is where the foam core is caulked to the rear edge of the shelf. It extended too far to miter it to the shelf and I was too anxious to hear it to ponder a solution. I may add a bit of foam core to the rear of the rear of the shelf for number 2. I took the choke strip off the rear panel so I don't think a thickness of foam core there will hurt anything, after all it's a kluge at best.
In the side by side pic the one with the mod is on the left. You can see through the vent to the rear panel in the other one. They are approx 10" tall.
Beauties by no means but will reside in my garage to be heard rather than seen.
In the side by side pic the one with the mod is on the left. You can see through the vent to the rear panel in the other one. They are approx 10" tall.
Beauties by no means but will reside in my garage to be heard rather than seen.
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I finally received my drivers from across the pond to construct speakers with double PA130-8 drivers. My plan is to build the cabinets from 15mm baltic ply but first I will make one in foamboard to test. I am a novice at speaker building and am wondering about lining and stuffing the speakers. 54oz/yd2 Swaledale wool underlay has been recommended on some forums - this is 12mm (0.5in) thick and I calculate has a specific gravity of 0.16. I found Triticum on Facebook has some nice photos of a single PA130-8 build where they have used felt on the bottom, sides and rear of the main chamber up to the level of the apex of triangle. Would Swaledale underlay applied in the same way be sufficient? I can get melamine foam cleaning pads here, which xrk971 has recommended for damping - would these be better? Should I also stuff the main chamber with polyfill/rockwool?
https://www.facebook.com/media/set/?set=a.963956566984162.1073741879.601735219872967&type=3
https://www.facebook.com/media/set/?set=a.963956566984162.1073741879.601735219872967&type=3
SredniVashtar,
The wool felt you have (12 mm thick) should be fine. Don't worry about it too much - line areas behind driver and adjacent to it with the felt. Also on bottom side and bottom section of back wall panel. Use moderate stuffing in closed end down to to driver. I use very loose stuffing right behind driver and bottom hairpin turn section. This can be adjusted to taste with measurements and listening to balance bass/mid bass output.
The wool felt you have (12 mm thick) should be fine. Don't worry about it too much - line areas behind driver and adjacent to it with the felt. Also on bottom side and bottom section of back wall panel. Use moderate stuffing in closed end down to to driver. I use very loose stuffing right behind driver and bottom hairpin turn section. This can be adjusted to taste with measurements and listening to balance bass/mid bass output.
xrk971, thanks I will try your recommendations. Hopefully will get this done in the next week or so depending on how the Yule preparations go.
Foam core being so easy to model with I'm thinking of some cabinet rear chamber extension experimentation with my quasi K5 hybrids. I'll wait until I have my amp and my final speaker positioning in my garage so that any subjective tests take the room and contents into account.
Geometry.
Looking at the foamcore thread, I just saw that xrk971 constructed a dual xki using mirror symmetry. I am just getting around to building mine using dual PA130-8 drivers. Is this the best way to go, and if so, with a diamond front vent and halving the height of the top and bottom ducts? Otherwise, I can continue with the standard design although the bottom section is coming out quite long to accommodate both drivers.
Looking at the foamcore thread, I just saw that xrk971 constructed a dual xki using mirror symmetry. I am just getting around to building mine using dual PA130-8 drivers. Is this the best way to go, and if so, with a diamond front vent and halving the height of the top and bottom ducts? Otherwise, I can continue with the standard design although the bottom section is coming out quite long to accommodate both drivers.
Foamboard prototype for double PA130-8 drivers.
Internal dimensions 445mm high x 203mm wide x 272mm deep
Duct 28mm high x 265mm long
Front vent approx 314 cm2
Internal dimensions 445mm high x 203mm wide x 272mm deep
Duct 28mm high x 265mm long
Front vent approx 314 cm2
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.
Yes, I started with your suggested size for a double and using your akabak script, played with the dimensions. Akabak suggested best tuning at 300mm, but I guessed on shortening duct to 265mm to take into account right angle bend and end effects.
At the moment, just lined but haven't stuffed the top of the rear chamber yet. The bass is really good - I don't have any equipment but a tone generator gave good response down to 45Hz, so they do seem to tune lower than akabak suggests.
It is a bit late to play them loud so will post more when I have played with stuffing, but I like them and will build up a pair in plywood. They certainly move a lot of air - you can feel the wind at the top of the aperture.
At the moment, just lined but haven't stuffed the top of the rear chamber yet. The bass is really good - I don't have any equipment but a tone generator gave good response down to 45Hz, so they do seem to tune lower than akabak suggests.
It is a bit late to play them loud so will post more when I have played with stuffing, but I like them and will build up a pair in plywood. They certainly move a lot of air - you can feel the wind at the top of the aperture.
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that looks fantastic !! - two PA130 should have pretty good kick - I've heard a fair amount of Karlson, 3 sizes of Karlsonator but never a double driver Karlsonator. This double looks like it deserves a plan.
Man those are some homely speakers. I love them. The "Rat Rod" of the speaker world. Dang.
https://www.google.com/search?q=rat...v&ved=0ahUKEwiAw4nZsrzKAhVBnoMKHZniDJEQsAQIHA
Maybe I should call them Quasi K5 Rat Rods.
The image is one I found while searching for a Ford Ranger. https://asheville.craigslist.org/cto/5400102647.html
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fwiw I could feel the air from the aperture on this K18 10 feet away at high levels and very little cone movement
I like most kinds of hot rods - need a mechanic to help me fix one once nice rotting in my driveway ;^(
its built on a postal jeep -
I've had chronic vertigo for decades - then heart probs
I like most kinds of hot rods - need a mechanic to help me fix one once nice rotting in my driveway ;^(
its built on a postal jeep -
I've had chronic vertigo for decades - then heart probs
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