Lyons' book is more thorough and complete, each chapter builds on the foundation of the prior ones. He aimed for a hands-on approach, not theoretical. It is v

Lyons' book is more thorough and complete, each chapter builds on the foundation of the prior ones. He aimed for a hands-on approach, not theoretical. It is very suitable for someone who isn't intimidated by math (of which there is ample), but would prefer to see examples of it worked out (especially visually). His list of tips and tricks at the end come in handy for specific applications (some of which I didn't know I need until I later came across them). Smith's book, on the other hand, is cursory and a bit more brief. It might leave you feeling that there is more depth there which you do not understand. Perhaps I feel this way because I read it online whereas I read Lyons' as a physical copy. Smith treats similar subjects but with less detail and fewer of the expert topics. On the other hand, it is a faster read and free. Both are good for beginners who want to understand DSP better!