A year or two ago I bought an ortofon 2M red for my Denon dp300f turntable. I paid the store where I bought the denon from to install the new cartridge, home service. This morning I listened to some records and noticed that the bass was lacking, sound was muddy and singer sounds like he had a phlegm.
Disappointed, I wanted to restore the original cartridge but decided to try some adjustments on my own before doing that. I was surprised to find out that the weight was off so I adjusted it on my own. The bass improved but the sound was still muddy. I checked the wiring and found out that the cartridge was not wired properly. Only the white wire was plugged correctly. The other 3 wires were plugged in the wrong socket. After reinserting then into the right pins the sound improved a lot. I then checked the alignment and discovered that the head was off axis by a few millimeters and the weight was not adjusted to specs. The sound improved a lot after these corrections and was a far cry from how it was when the guy installed it. Lesson learned, can’t trust the installer blindly.
here's the mismatched wire to pins