Low pass or high pass filter using impulse response.

I have a .wav sound file that I want to filter with either a low pass or high pass filter using impulse response. my code is the following

[x,fs] = wavread('1.wav'); h = [-1 1]; %impulse response coefficients y = filter(h,1,x); %filter

I do not know which values of h I should pick to get low pass or high pass. I would like the filter to be as ideal as possible. Thanks.

Answer 1

[Image Analyst]

All positive weights will blur the signal and be a low pass filter. Negative weights will be required to do a high pass filter. To get more control of what frequencies get filtered, you will have to do it in the spectral domain - use fft().