This is not exactly a Chambord of Elipson type enclosure . The Cambord has the speaker on focal plane and stands upright , the sphere is rigid with bass reflex and internal resonant cavity . The sphere of this enclosure is 3mm thick longitude wound fiberglass made of two half spheres loosely atached with elasatomer impregnated linen tissue that serves also as damper . The resonance of the sphere is adjusted by latitude stiffener glass fibers , to be that of the speaker (65hz) but critically damped . The enclosure is installed in a corner where the area of the sector is that of the sphere , for acousticaly loading .
The speaker used is a low cost 5$ JBN , Chinese manufacturer of JBL , and has a genuine JBL diaphragme , but with large cap to hide the high frequencies . Although it has a very heavy 4 layer thick wire voice coil to be a woofer, it has very bright sound once the cap is taken off . The frequency responce is ultra flat up to 8khz with a 6db sharp resonance at 4.3khz standing waves eliminated by a notch filter and the responce extanded to 10khz by adding a replacement aluminume dome . The back plate was resonant , eliminated by gluing on it 2lb hammer head . Two home made super tweeters symmerically mounted with all direction phase alignment, diffuse 90° linear coverage . The impedance curve is that of the driver resonant at 63hz 32ohm but of very wide ,12 ohms at 35Hz and 105Hz . With the efficiency of the speaker 88db enhanced by 6db and mechanically damped speaker is best suited for single ended triode . The frequency responce at bass , goes down -6db at resonance to notch at 52Hz -10db and rise back to zero db at 43hz (room resonance) the only resonant, to fade back -10db at 38Hz. This enclosure yields very high presence sound as horns but totally non resonant.
Now I will transforme a more serious mid range P Audio SN6 200F speaker into a full range , but with resonance of 50Hz . The notch frequency then may coincide with the room resonance.
Please give your suggestions , as I am in short of new ideas .
Kokoriantz
The speaker used is a low cost 5$ JBN , Chinese manufacturer of JBL , and has a genuine JBL diaphragme , but with large cap to hide the high frequencies . Although it has a very heavy 4 layer thick wire voice coil to be a woofer, it has very bright sound once the cap is taken off . The frequency responce is ultra flat up to 8khz with a 6db sharp resonance at 4.3khz standing waves eliminated by a notch filter and the responce extanded to 10khz by adding a replacement aluminume dome . The back plate was resonant , eliminated by gluing on it 2lb hammer head . Two home made super tweeters symmerically mounted with all direction phase alignment, diffuse 90° linear coverage . The impedance curve is that of the driver resonant at 63hz 32ohm but of very wide ,12 ohms at 35Hz and 105Hz . With the efficiency of the speaker 88db enhanced by 6db and mechanically damped speaker is best suited for single ended triode . The frequency responce at bass , goes down -6db at resonance to notch at 52Hz -10db and rise back to zero db at 43hz (room resonance) the only resonant, to fade back -10db at 38Hz. This enclosure yields very high presence sound as horns but totally non resonant.
Now I will transforme a more serious mid range P Audio SN6 200F speaker into a full range , but with resonance of 50Hz . The notch frequency then may coincide with the room resonance.
Please give your suggestions , as I am in short of new ideas .
Kokoriantz
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