The home stereo market is so overrun with hucksters and scam artists, it's hard to know what is really science. Cables are the biggest market for scam items.

Get your hearing tested by an audiologist. Chart your results and know what you can and can't hear.

Buy audiophile recordings when available. So much of today's music is "lo-fi" by design and intent. Do not use internet downloads to judge fidelity. Even vinyl and CD releases are often mastered for the MP3 or radio market and lack dynamic range.

Do not use filters and EQs to "correct" from song to song. Use these tools only to tune your speaker system to the room they're in. Before you reach for the EQ as a solution, look into room treatments and speaker placement first.

Get some "critical listening" instruction and learn the basics.