I just picked up a pair of Tannoy Reveal 502 powered monitors. Nothing special about them, but they have a solid rep. Input is 3.5mm, which I'm running from my iPhone 8+ (Apple Music) via a lightning-to-3.5mm adapter then a basic cable. Sound is inconsistent, anywhere from below average to really awful, with vocals often disappearing almost completely.
I changed cables and played around with the settings on the Tannoys, and even resorted to RTFM, but could not improve. Finally I tried running the 3.5mm input from my Macbook (Apple Music). Success! Sounds great. Also sounds fine running 3.5mm straight from iPad (no adapter needed) to monitors.
So I'm wondering if my issue has to do with the phone or the lightning-to-3.5mm adapter? I run headphones straight from the adapter with no issues, and have run 3.5mm from the adapter through a headphone amp with no issues.
Any ideas? Thanks.