[Spender]

I've had all the caps replaced in my Tannoy Canterbury. I'm very happy with the sound apart from a hump around 120 - 180 hz (Vocals low range sound to much i your face),  I've watched the GR research Notch filter video.  My question is, does any one know how i can find out what values i need on the cap, coil and resistor?  Cheers

[Danny Richie]

Honestly, I have done so many of them that I just grab the values that I know will be close and then hook them up and run an impedance sweep to fine tune the values and figure out if I want a narrow or wide band fix.

I then look at what it does to the output levels and make adjustments to the resistor value to control level.

Note too that a notch in that frequency range is going to need more than a 10 or 12 watt rated resistor.