OK, now I am confused. First there was the Karlson, then Karlsonator, now???? Is this a new tweak? As you know I am waiting on a woodworker friend to build me cabs and he told me the other day that he would be back on his feet in two weeks. So, I want to build something starting with the letter "K" with the below drivers☺. Which cab would you suggest. Here are the drivers that I posted on the other thread.
Those would work in either a Karlsonator (which I gave you a design for already) and since Qts is moderate and Vas is small it may work in XKi. I would have to run sim but don't have akabak for another week. To be safe I would go with K'nator as the XKi is still new and we have had mixed results with different drivers.
thanks X - so the ferrite version at $19 would be logical FaitalPRO 3FE25 3" Professional Full-Range Woofer 8 Ohm
I agree freddi - perfect size for computer speakers. I'll play around some more with the B3Ns with slightly bigger boxes that I'll just wing while waiting for X to get back up and running with his sims. That's the beauty of foam core - protoytping with minimal investment in time and money!
To first order approximation use a bass reflex calc to get volume and set equal to front and back chamber and vent set cSA and length for rear chamber but reduce length 15%. Set ratio of volume at 4:1 for rear to front. Better than nothing.
Excellent - thanks. I've worked out a box to try and will put it together tomorrow.
Cheers!
Those are a drop in substitute for your 0.4x K'nators and will give you +6dB boost in sensitivity compared to the TC9FD's. They sound quite nice but do have a slight cone breakup ringing at 10kHz - not too bad though. For critical listening the Vifa is better but for general about the house music playing, the 3FE25 is great because it plays louder. The mids are wonderful on it so great for vocals.
I like your attitude! That is why I foam core prototype - you don't feel hosed if it doesn't work out. But surprisingly, I have had very few total busts. The XKi for the RS100 took about 2 hrs and 1 sheet of FC so I would not have been bummed if it did not work.
I have 2 FE83's that per the reports do not work in this bandpass XKI box.
So since I may not try to return the FE83s (the return shipping costs ends up making that pointless) what would those speakers be good for?
I've got a couple CX8s and some PRV horns ordered, and have the CNC guy programming the cuts for that. I wonder how good that will sound with a much more stiff type of panel? (graphite, or fiberglass skinned honeycomb, scrap so the price is right, free, except for compensating the CNC guy for his work. Maybe by doubling up on speaker components ordered, of the set that work best, since he wants some.)
So since I may not try to return the FE83s (the return shipping costs ends up making that pointless) what would those speakers be good for?
I've got a couple CX8s and some PRV horns ordered, and have the CNC guy programming the cuts for that. I wonder how good that will sound with a much more stiff type of panel? (graphite, or fiberglass skinned honeycomb, scrap so the price is right, free, except for compensating the CNC guy for his work. Maybe by doubling up on speaker components ordered, of the set that work best, since he wants some.)
A carbon fiber honeycomb XKi Beta8cx is VERY COOL! 
I think it will sound better than my foam core and cardboard composite. You want a stiff but damped box and carbon fiber in a matrix has natural damping. If you wanted to gung ho, make a CLD sandwich of the honeycomb panels and some sort of rubber sheet or latex caulking like I did.
I have never personally used a FE8x but it seems like there was a design in the Martello thread that says they soubd good.
I think it will sound better than my foam core and cardboard composite. You want a stiff but damped box and carbon fiber in a matrix has natural damping. If you wanted to gung ho, make a CLD sandwich of the honeycomb panels and some sort of rubber sheet or latex caulking like I did.
I have never personally used a FE8x but it seems like there was a design in the Martello thread that says they soubd good.
I've got some sheets of 1/8" thick fiberglass honeycomb. Or, I could
I've got some sheets of 1/8" thick fiberglass honeycomb. Or, I could just carve away the internal honeycomb, of one of the 1/2" or 1" thick graphite honeycomb so that I have a thin piece of stiff panel skin. I could then put a piece of rubber or rubber foam in between (I think I've got some thin [1/64" thick?] pieces of open cell rubber foam. Weak as hell, it tears if you look at it cross eyed. But if glued on with silicone or better yet Lexal, it would not weaken the sandwich at all. Since the CNC guy is talking about cutting out dadoesque slots for the internal panels, for contact area, and so that I do not have to try to attach the honeycomb together with glued in inserts. Lexal (or possibly epoxy) glue alone should be enough to hold the panels together, since there will be a large contact patch in the joints.
I've got some sheets of 1/8" thick fiberglass honeycomb. Or, I could just carve away the internal honeycomb, of one of the 1/2" or 1" thick graphite honeycomb so that I have a thin piece of stiff panel skin. I could then put a piece of rubber or rubber foam in between (I think I've got some thin [1/64" thick?] pieces of open cell rubber foam. Weak as hell, it tears if you look at it cross eyed. But if glued on with silicone or better yet Lexal, it would not weaken the sandwich at all. Since the CNC guy is talking about cutting out dadoesque slots for the internal panels, for contact area, and so that I do not have to try to attach the honeycomb together with glued in inserts. Lexal (or possibly epoxy) glue alone should be enough to hold the panels together, since there will be a large contact patch in the joints.
I'm also wondering how to finish the graphite panels. To show off the graphite, for the versions of the panels that are shiny and smooth (unfortunately also scratched) would require multiple sandings and clearcoat layers. Or I could just bondo over the scratches and then paint the panels with whatever color and paint I wanted to use. Though I do not want to fool around with covering the panel with vinyl or leather. (too much work)
XKi-B3N
I put together one XKi-B3N box based on your guidelines and after a brief listen alongside the 0.4X Vifa Karlsonator I think it sounds pretty good. While it can't reach the overall loudness of the Karlsonator it seems to have about the same level of bass extension. Certainly good enough for me to use near-field without a sub. I'll go ahead and put the other box together and I'll try to take some measurements.
Would be very interesting to see how it sims and if I got anywhere near optimum dimensions?
I put together one XKi-B3N box based on your guidelines and after a brief listen alongside the 0.4X Vifa Karlsonator I think it sounds pretty good. While it can't reach the overall loudness of the Karlsonator it seems to have about the same level of bass extension. Certainly good enough for me to use near-field without a sub. I'll go ahead and put the other box together and I'll try to take some measurements.
Would be very interesting to see how it sims and if I got anywhere near optimum dimensions?
Attachments
I have been following your experiments in foam core and find it all fascinating. Unfortunately, we don't get foam core here in South Africa, nor do we get much for our currency, but I am really keen to start ordering stuff and building up my hi-fi (from scratch - "ab initio" ha ha).I would very much like to know how the PRV drivers do in this kind of enclosure. I guess if you had tried them, you would have posted.