What are the disadvantages of IIR filters (compared to FIR filters)?
• They are more susceptable to problems of finite-length arithmetic, such as noise generated by calculations, and limit cycles. (This is a direct consequence of feedback: when the output isn’t computed perfectly and is fed back, the imperfection can compound.) • They are harder (slower) to implement using fixed-point arithmetic. • They don’t offer the computational advantages of FIR filters for multirate (decimation and interpolation) applications.
