# Will a 47uf 100 volt cap block 100 hertz

Going to hook up (2) Anthony Gallo nucleus mini speakers directly to Nad c326bee intergrated amp. Anybody know if a 47uf 100 volt capacitor is sufficient to block 100hertz signals and below so I don't blow these small guys. If not what size? Have emailed Gallo no response. Thanks
5 responses
 11-22-2015 3:09amIf the Gallo is 4 ohms you'd need apx 400Uf for a first order 100HZ crossover and 200uF if they are 8 OhmsBest of luckPeter 11-22-2015 3:58amIt all depends what load to ground (speaker impedance) this cap sees.A 47uf in series will have to see a load to ground after it of 30ohms to be -3db at 112hz.If the load is 15ohms to ground then it's -3db at 56hz.If the load to ground is 60ohms then it's -3db at 224hz.For yours If the load is 8ohms and you want -3db at 100hz you need a 200uf series cap.If he load is 4ohms then you need 400uf.Cheers George 11-22-2015 2:23pmI agree with George's calculations, except that he inadvertently interchanged "56" and "224" (or "15" and "60").Be sure, of course, to choose a non-polarized capacitor.Regards,-- Al 11-22-2015 10:36pmAlmargOops! brain fart, thanks for the heads up, too late to swap. Cheers George 12-09-2015 5:39amThe capacitive reactance of a 47uF capacitor is 33.86 Ohms at 100 Hertz.Capacitive reactance = 1/(2*pi*frequency*capacitor value)