So, thanks to a very generous forum member I got some fostex 208 sigma drivers for a great price, and decided to build the kirishimia cabinets (should have gone to the gym for 6 weeks!)
Already having the fostex t90a (as the 208 sigma is a 'wide range driver, not full range it needs upper support imo)
So.
I am lucky that I work for a small furniture company (I am no maker!) And have access to some very expensive saws etc.
Cut a long story short here are some pics.
They are progressing in an American black walnut veneer finish with plain grey sides.
Any questions please let me know.
For the veneering I only (now) use contact adhesive, the evostick thixatropic is just a joy to work with, and any bits that don't stick, nothing that a hot iron won't sort.
Already having the fostex t90a (as the 208 sigma is a 'wide range driver, not full range it needs upper support imo)
So.
I am lucky that I work for a small furniture company (I am no maker!) And have access to some very expensive saws etc.
Cut a long story short here are some pics.
They are progressing in an American black walnut veneer finish with plain grey sides.
Any questions please let me know.
For the veneering I only (now) use contact adhesive, the evostick thixatropic is just a joy to work with, and any bits that don't stick, nothing that a hot iron won't sort.
Attachments
The metal bracket will vibrate..maybe a chunk or box of wood mounted on the side? You could make a box open on the front (/back..) to fit around the tweeter affixed to the main speaker with screws in brass inserts of some kind.
Not a bad idea, we are looking into various non resonant materials to avoid that.
Sorry, I got an edit in there. What might look cool is a solid piece of wood or ply with a cylinder drilled out of it that fits right around the tweeter, then attached inside the hole with screws into inserts in the side of the cabinet. you could round the side, like a D shape. You have nice tools to use! 🙂
Very impressive work, you're flying along with the build. One possibility for the tweeter:
That was my plan before passing the torch. Same driver setup and similar style cabinet, $12,000!
That was my plan before passing the torch. Same driver setup and similar style cabinet, $12,000!
what would be the effect if I placed the tweeter atop the main cabinet, seeing as its crossing at 17khz, does it need to be as close to the main speaker.
I was wondering this too. I was thinking of it in the upper horn mouth would look pretty cool, in a corner. Seems like at 17khz any distance from the center would be 'too much', so..
You know what I didn't even think of that, bloomin good idea, and easy to experiment without drilling any holes
Presumably when you say you are 'crossing at 17KHz' it isn't a brick wall; if it's a 1st order electrical, then assuming a nominally flat FR, impedance from the T90a, it's a -3dB corner frequency only, so is only going to be 6dB down at 8.5KHz, 12dB down at 4.25KHz, below which this will naturally accelerate as you hit the driver's mechanical rolloff. That's not very much, so large separations are not likely to be a good idea or the phasing will go to bits.
Being as it is being crossd so high, it needs to be as close as possible.
dave
dave
Thank you for this. I will continue with the design that has the tweeter nice and close.
Looking good, have you got enough access to chamfer the inside of the driver hole? It's recommended on horns to help with airflow
Can't seem to find any negative chamfer router bits...any ideas on the best way to do a negative chamfer.?
Cheers