Thomastik JF 346

Feel good tension-wise in std tuning on 34” scale bass - usually playing 45-135 nickel roundwounds (std tuning, 34" scale as well), can't complain at all - maybe these strings feel slightly softer, but I'd say not much. Low B doesn't feel loose/floppy at all, feels even a bit tighter than A/E. But no complaints about tension balance - nothing stands out much (if noticeable at all).

Nitpicking - maybe they are not glass-smooth (E, low B strings) - that's noticeable, but not irritating - can feel some small "gaps" in winding with nails + mentioned strings feel like adding a bit of resistance/drag when sliding.

Sound is up to my liking - they have some mids/clarity to them + I'd say they sound kinda bright as for flats. I did not notice sound to become worse after a couple of years of moderately active use (at least few hours per week).

Had them on my bass since mid-2018 and managed to break the D string when stretching (really hard!) while tuning to compensate for cheap nut's drag. Pretty sure they could last another few years.

In general - awesome set, ordered these again.

These strings are great, really, really great. They are slick to the touch and have just the right amount of tension on my 35" 6 string bass. I replaced my previous round wounds with these flats, as the previous strings were just too bright for my taste. These have that nice low 'thump' and a fantastic tone that is harmonically rich throughout the full range. I use these with my MTD USA.

I have used these strings now for a fair time, and have found that they last really well. You could probably get away with never changing them if you took care of them and wiped them down. I still make good use of slapping and popping occasionally too, and the EQ can make up for the 'less bright' tone of these compared to rounds to my tastes.

Very much recommended.

I'm using these strings with my fretless Harley Benton B-650FL BK Progressive Series Bass.
The bass came with round wounds, then I replace them for nylon strings, so there we have extreme to extreme of sounds, the crispiest to the warmest, but with these Thomastik JF346 metal flat wound strings you get some crisp tones of metal strings with some balanced mellow warm sound but without sounding too classic, still keeping the power and dynamics of a metal string, it erases those excessive long over tones. Ideal for slides.
I love these strings, my favourites till now.