You made a simple topic too complicated and new audiophiles usually have this kind of conclusions.Due to my location, its near impossible to audition/borrow any component.
You may adopt following points if u wish to listen your speakers at fullest.
1. Make sure you test your speakers with Audio CDs, better buy a dedicated audio CD player with a good dac inside.
2. Use Belden 8471 speakers cable which costs 80₹ per foot and shall open treble which u may be lacking till now.
3. Use high quality RCA cables. If u cannot buy high quality RCA cables, make one for yourself from Cat5 cables (one strand RCA only).
4. Keep tweeter height at ear levels.
5. Upgrade Crossover with high quality capacitors supplying tweeter circuit.
6. Use shortest length for RCA as well as Speaker cables. 1 foot RCA and 5 foot speaker cables is usually fine.
6. Your speakers are 4 ohms, you must use a high current amp to gain most out of your speakers.