PLEASE HELP NOTCH FILETER FOR TBw3871sc Needles

[amozos]

Hi I and making a pair of TB w3 871sc Needles, I will use a Gain clone amplifier lm3886.
Do you think that I need a notch filter fot the TBs? How could I make this notch filter?


Thanks in advance

 

[wintermute]

Hi I don't know the speaker you are mentioning, but if you want to learn about notch filters I found this wikipedia page invaluable. It takes the guess work out of it!

RLC circuit - Wikipedia, the free encyclopedia

go to the parallel RLC section (but it helps to read the preceding stuff as well.

If you are like me and shy away from maths, it looks intimidating but you really only need the Q formula

and the Wo formula

to be able to work out a filter suitable for your desired frequency. Note that Wo is in radians, so you need to divide by 2pi to get Hz. (edit: the original formula I linked to was incorrect I've now fixed it, sorry for any confusion!)

Swapping the values for C and L will change the q (without changing the centre frequency) and the resistor determines the amount of cut.

Choose a value for C or L and the frequency and then work out what the value for the unknown component (L if you chose C) is. adjust until you get usable values and the desired Q. The higher the Q value the narrower the notch will be.

I found this to be a much better starting point for simulation (very close to the desired frequency) than the methods I'd found in my speaker books.

Tony.