These are a few books that are highly recommend to start with, if you are interest in audio design and how to achieve good audio sound from your HiFi system. Also to boost up your audio knowledge.
1. Noise reduction techniques in electronic systems by Henry W. Ott , John Wiley & Sons
2. Master Handbook of ACOUSTICS by F. Alton Everest & Ken C. Pohlmann , Mc Graw Hill
3. Designing Audio Power Amplifiers by Bob Cordell , Mc Graw Hill
4. Audio Power Amplifier Design Handbook by Douglas Self , Newnes
5. The Loud Speaker Design Cookbook by Vance Dickason, Audio Amateur Press