Is it possible to change the FIR filter -6 dB break point to -3 dB when using the FIR function or the FDATOOL in the Signal Processing Toolbox?

I want to design an FIR filter with a -3 dB break point. All the IIR filters have a breakpoint of -3 dB break point.

Answer 1

[MathWorks Support Team]

The cutoff frequency in FIR designs usually corresponds to -6 dB. There is no way to change the break point to -3 dB point. The one exception is the maximally flat filter which can design both IIR and FIR filters. From the FDATOOL, choose "Maximally flat" for the design method. From the command line, use the MAXFLAT function and be sure to include the 'sym' option for FIR design.