So I've read here Multi-Stage digital FIR filter vs Single stage FIR filter. Which is better? if you want to interpolate by a great number, it's always better to do so in multi-stage interpolations so it won't be as costly as a single interpolation. Let's say I want to interpolate by 64, and I choose to do it in 3 stages: first time interpolate by 2, next by 4, and last by 8. I'd use the first stage to pulse shape my input signal but my question is what to do in the remaining stages? Any lowpass filter would be good to go?