I think the speaker cables made the biggest leap in detail and realisim. Noise floor seems to be lower as all my vinyl just sounds better.
Still in the break in period for my set so my comments are based upon the demo pair I was using. When I added the XLR, it smoothed out a hint of mid range glare and opened up the soundstage to a ridiculous degree! I used the Reference Recording of Copland Fanfare for the Common Man as my reference for soundstage, imaging and decay and Jane Monheit, Over the Rainbow from her album Come Dream With Me as a mid range torture test.
I listen to a wide ranging of music and cranked some AC/DC and I swear the kick drum sounded like it was right in my room! Sarah McLachlan’s Angel almost moved me to tears. Her voice just floats in the air. My daughter who is not an audiophile thought the realism was “spooky”.
These cables are pretty unforgiving and seem to extract every bit of detail from the music so they will reveal blemishes in poorly recorded content or weaknesses in your system.
I also auditioned some cables from Purist Audio Design which were very musical and more full bodied but not as accurate and detailed as the HFCs. Each provided a different character to my system and in the end I decided on the HFCs as they brought the sound in a direction that I didn’t realize was possible.
Couldn’t go for a full loom because of the cost but I am a believer now so I’ll get there over time.
Associated gear include Bryston BP17 Cubed pre amp, Bryston 4B cubed amp, Focal Sopra 2s and PSA DirectStream senior.