So, I had in the garage, since some 20+ years, this obscure RCF 10" 4 ohm woofer just doing nothing. Recently I said: "I'll do something with it, but nothing really cumbersome". So I built
the cab, note the two separate 12 and 30 litres rooms for the loudspeakers, then added a
Ciare CM161 (80 w 4 ohm) 6" woofer in series and a piezo tweeter in parallel (with a 10 ohm resistor in parallel to the piezo self and a simple 10 uF capacitor filter). Actually I was looking everywhere to add the
Faital Pro 6", instead; but could not find one so I went for the Ciare. And in the end it was good: the Ciare has a Fs of 66 hertz, so it goes lower than the Faital (Fs 100 hz).
Note that having unluckily the 4 ohm constraint given from the main woofer, I had to add the Ciare
in series to have a safer 8 ohm average global cabinet impedence. Being it the weakest element of the chain, I wisely protected it installing a 3,2 amps fuse, that is well suited for the max current tolerated by its coil (5 amps for 80 w / 4 ohms). This reduction factor of approx 0,7 is due to the inertiae that a fuse has in burning when 5 amps are applied to it: it might actually burn the coil, instead! Therefore a 3,2 amp fuse will be just good and fast enough.
Looking at the overall result, I guess I was lucky, because frankly I had no idea about what could come out of this... ehm... "experiment"! The Ciare 6" mid/woofer is evidently less efficient with respect to the 10" RCF; so the cabinet has the lows, the mids and the highs. I also thought: "if it is too midrangey I will tentatively add a port to the 10" room" but it is not necessary. Only thing is that it will only tolerate some 160 watts, I guess; so good enough for the pub and as home practice cab!!! Its sound is even, analytical, quick and brilliant! More on the hi-fi side, I would say.
Money: excluding the 10" woofer that came from the past, I spent something more than 100 euro, including the Ciare, the wood, the corners, carpet etc... Here is the little beast:
V.
