‘About 55 lt bass reflex cabinet from a dismessed couple of RCF speakers which I was not able to make singing as good as I liked, they always had too loud bass with the original RCF dome mids too laid back…
Generic 30″ woofers with generous bass (until I combine them with the 4 ovals)
Dismessed oval RCF wide band “speech” speakers from classrooms, mounted on open baffle
plus Philips 1″ dome tweeters
Additional back Peerless 1″ dome tweeters, opposite polarity, still to be fixed
Will probably change the Peerless tw with another couple of Philips tw, a bit more efficient
Woofers feeded through the original filter inside the RCF cabinet (?) abt. 500 Hz. Plan to try an home made 2nd order filter, 5mH + 50uF, maybe more direct to increase a bit sensibility.
Mids RCF trough pass band 1st order, 80uF PP + 0.39 mH coil, 5.6 Ohm heater for damping down. In this way the ovals are very transparent and direct. Voices are very realistic.
Tweeters 1st order, 4.7 uF-100V, wima caps.
The D’Appolito style configuration helps creating an extended vertical stage.
Sound is quite engaging and live. Soundstage is big. The bipole radiation is very nice.
Only thing I need to gain some bass. Half rotating the bass knob on the Rotel amp balances well.
After trying with the xover mod, I will try opening and playing with a wider bass reflex port, various lengths, thus sacrificing the bass extention but gaining few dbs.Made with all second hand parts’