Round radiating tweeter, aka "Enterprise 1" tweeter!

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Hi all.

I want to show here my 2 surround-back speakers. Wanted to keep the costs low, so made for a 20mm CRB-40 neodymium car tweeter a dispersion cone. Woofer is an old bextrene Audax unit.
 

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Turn in mind picture 180 degrees: Enterprise!

Btw sound is very good for such a cheap tweeter. Removing metal grid before dome was the best modification. Because round radiating highs its like the tweeters can communicate with eachother, very good soundstage in treble. You can walk around the speaker and hear no difference in treble output.
 

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Thanks Nemophile, Tade.

Cabinet is simple: MDF, the roundisch sidewalls are from 2 layers 4 mm fibreboard, soaked in water and bended/ glued/ nailed over pre curved bottom-top plate. Inside is a brace from side to side, and some dampening sheets on all walls. Will glue some strokes of glass in too. Cabinet has rear-firing bass tube.

Veneering i did in a other way as i did usual, not with tixotrope glue(lot of solvents, i get a sore throat of it) but i did this with the "Klang & Ton" way: woodglue on both sides, let dry 20 minutes, then iron it on, in whool preset of iron. Veneer is paper-backed cherry.

Stand mounts i am thinking of allready.
 
Thanks.

Info for others: i got the 4 bextrene speakers from mr. Geenius.

Hi Geenius: The 17 cm bextrenes work good, less break-up problems compared with bigger 20cm bextrenes from stereo pair i use. But sometimes i think some details are missing with heavy dampened cones like bextrene. But one problem is occured allready, the 20cm has a lot larger excursion than the 17cm ones! Its time to finish my sub.

Sqlkev: The dispersion cone has a sort of parabolic shape. Will make a drawing of it soon and post it. It indeed radiate the sound.

Rho: finisched with matt acrylate clear spray in 2 layers to emphasise the woodcolour, last layer is alkyd matt clear spray. Inbetween mild sanding, before last layer i sanded with water and fine grain sandpaper(800/1000)
 
Hi Noah, thanks for answer.

First experiment was with straight cones, 45 degrees topangle. Not satisfied with reflection result, i made some drawings. This cone reflects very good, has some reflection in vertical area too. The dome has to fit to the dispersion cone, so parabolic is better then.
 
tubee said:
Rho: finisched with matt acrylate clear spray in 2 layers to emphasise the woodcolour, last layer is alkyd matt clear spray. Inbetween mild sanding, before last layer i sanded with water and fine grain sandpaper(800/1000)

So it shouldn't be too difficult to get a nice finish like that. I realy like it. Not too shiny, not too dull with a nice accentuation of the structure in the wood.
 
45 degrees topangle

Mistake: I ment 90 degrees, 45 is the setting angle on a lathe to make a topangle of 90 degrees.

Rho, it was difficult to find acrylate paint (this empahsises the wood beautiful) because environment matters this spray is difficult to find. In high-gloss it can be found more easy, but high gloss emphasises the wood more than (silky?) matt paint.

I let some matt clear spray made to order in a car-paint store, but it had some faults on last finish (cloggs, or how is it called) thats why last layer is alkyd. But alkyd has a whitish finish on bare wood, did some tests first. The center speaker has 2 layers acrylate. (has the same design-basics, and woofer)

Dry sanding between first 2 layers is done with Scotch brite, and with water + 1000 grain waterproof sandpaper for last layer to make it smooth and flat.
When you have a good spray, will get a very professional look.
 
Hi noah

I promise you i will make a drawing soon. At the moment will go to bed for a sleep.
The outer diameter of cone is slightly larger then dome diameter, and the curvature is indeed concave, i turned it on the lathe "on the eye" and it was slightly difficult to make the 2nd exact the same (after listening test of 1st) but i managed it.

goodnight (at least for me it is night ;) )
 
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