# Compensating for group delay in FIR with symmetrical coefficients

Suppose I have a sinusoidal signal of 50Hz sampled at 6.4kHz and I wished to filter it at:

Band pass: 160Hz, Bands stop: 800Hz, Apass:0.1db, Astop: 106db

For a FIR filter order of 40 I would get 41 number of taps. The group delay would thus be (41-1)/2 = 20.

Am i wrong in thinking that if I extended (/zero padded at the end of) the data block size to be filtered by the estimated group delay above, I would be compensating for the group delay?

For example if I had 128 samples (corresponds to a full sine cycle at 50Hz-Fs=6.4Khz) to be filtered and added the group delay 128+20=148. Now, if I were to filter these 148 samples with the above stated filter, would I not get a signal with no group delay?

Thanks Alex