Archie,

I have posted pictures of some Big OB and Medium size I made quickly to test .

Archie,

Page 25 and 26 of this thread contain Tooppy's pictures of the green board test baffles.

John

Well, only one picture appeared

Thanks for the picture link.  I remember seeing them now.  I'm not surprised that the foam boards didn't do much for the sound.  These new enclosures look interesting.  Hopefully, they'll do it for you.  The F15 driver is really special.

Tom,

I just upscaled for a 15' and don't believe very precise measurements are critical, they are not.
I tried different kind of bracing/internal partition, it make virtually no differences.
I even tried adding a tweeter, compression and cone, with a crossover 18db at 1800Hz, the thing works better alone.
As such it might be good to try a phase correction of some kind to see, it's all depend of your room.
Earlier I mentioned I listen at very low level, with an OB I lose a lot.
With this K I have back all the music, it fill up the room and it gives the feeling I play to loud but it is not the case, I hardly hear anything if I go to the next room.
Big box reproduces large sound and I love it. The Japaneses play big JBL in very small listening rooms, they are right.
OB's placement need big rooms as they must be at least 4 feet away from any wall, that is to say in a dedicated room. I am happy I tried to realize it.
Let me repeat that the material used is very important, if you use plain wood you may need damping and then you enter probably into very unpleasant experiences of trials/errors which might never be conclusive so deceptive on what a K could be.

Thank you for the clarification, from your last response I was still a unsure exactly how you determined size/volume.

Looking at your photos and comparing them to existing Karlson enclosure plans, your build looks more like a quarter wave horn? Other cabinet plans show a rectangular vent or slots for the driver back wave to exit, although Karlson enclosures seem to vary a bit ?


Tom in Lafayette

Thanks for the clarification - I have similar listing issues, where Karlsonator may be a better implementation choice. I will continue to research.....


Thanks,
Tom in Lafayette

Toopy, from my somewhat limited experience as a DIY speaker builder, and some rather ancient history as a custom cabinet maker, I think you're doing a brilliant job. You're designing solutions that work in your space. Not an easy thing to do. Good job.

Hi, Troopy,

Looks like your project is coming youir way. I intend to goof some with this Karlsonator idea, but mainly, you have made me want to gather up some of those F15 Lii drivvers.



Thuffering Th...

 I admire your bravery but dam your judgement. Pretty forward for me to say it like this, but by looking at your work, I see that you have talent in wood and other material work. Chip board and acrylic, unless both were much thicker, look like nothing but resonance in a horn design. I am not a big MDF fan either, but I know that its stiffness and density are easily superior to chip board. It would be wise to do some radical bracing and hope that it helps. BTW, I am impressed at the choice that you made for the design of the cabinet. Never heard one, but it is tempting for me to build some day.
I guess that the final test is listening and deciding or not from there.