technique issues aside, yes there are strings that seem to just scream on contact with frets. So it could be a multistage process in 'finding your right string' What kind of
sound and feel are you going for?
(based on your comments lets jump to #3)
1. fine-tuning technique (will get you 80-90% there)
2. string selection (selecting a bright zingy string will only complicate the issue)
Rounds and stiff bright strings 'tend' to enhance the attack. So try half rounds, pressure wound, tapes —
keeping in mind the material. SS, chromes, tend to be bright
if not harsh on the top end and very 'contact' sensitive. Try Nickel or Labella tapes (Gold-White, Copper-white, and whites), LaB Black are an option too for the 'darker side' but again, it depends on what sound you're after. I'm currently really digging
Copper for my sets, they re warm and sing great.
3. Setup
I'm pretty sure I play with higher action than most, so instrument setup is not an issue. I'm purely looking to see if someone had suggestions specifically about flats that were less Clanky when pushing the low strings to the fretboard with the left hand. Let's pretend the right hand doesn't exist for now.
I think this^^^
may be the issue. a higher action requires more 'energy' to place on the fret. This is not only about the players control BUT
the design of the chosen string. A stiff string will ring on contact due to the 'added' tension applied in pressing the string down. (Again everyones style and playing situation is different so 'clank' may not bother some in heavy hitting or dense musical situation.)
Experiment with the nut height, relief, and string type. It can be a bit of a rabbit hole but very illuminating once you figure out what string and setup
sounds the best/works for you.
I like my low B to be
tall at the nut so that the relative action down the neck about equal. Depending on your neck relief, the 7-9fret would have
slightly more but this is marginal at best. I recently added height to the B as I play
a lighter flexible set of strings. (If I were to go back to a hex core/stiffer string I would lower it to the point of just enough LH pressure to initiate the fretted note—again everyone is different)