How to connect two digital filters in series?

Hello, I've got two filters with the following diff. equations:

y1(n) = x1(n-L) (x1 input, y1 output of the 1st filter)

y2(n) = g*y1(n) - ay2(n-1) ( y1 input, y2 output of 2nd filter)

If I want to get the result of the two filters in series? I know how to use filter for a single system but how to obtain convolution of both filters?

I'd like to include a drawing of system but right now I can't

cheers, m.

[Rinus Boone]

You can convolve the A coefficients and also the B coefficients to get the cascaded filter.

Answer 1

[Honglei Chen]

You can use dfilt.cascade to achieve this

http://www.mathworks.com/help/signal/ref/dfilt.cascade.html