It can depend on the style of music you play, and other contextual stuff, but some like bright strings & others don’t. Or how bright?
Brightness can help you cut through the mix, or be too shrill.
Of course the strings aren’t the only factor.
But just isolating strings for a moment, what is your preference?
Mine has always been for bright strings, so I tend not to like flatwounds.
If it’s too bright I can “de-bright them by amp or bass settings, EQ pedal, or technique.
I find it easier to take away brightness than to add it.
Of course YMMV, even if you like brightness as well.
So what are your thoughts?
And if you play guitar as well, does it differ for you?
Since the guitar is midrange, my thoughts are pretty much the same for both guitar and bass.
Thanks.
My thoughts? Well...
1. I learned to play bass in 1968, on a friend's '68 Rick 4001. It wore the factory-installed German Maxima 4440 Flat wounds. So, I've been... inclined... to flats on a bass ever since. Currently, only two of my 29 basses wear rounds (and one only does so because it's new, and I haven't yanked them off yet); two wear tape wounds (and one does so, because it was built to sound like

with anything else); all the rest wear various brands, scales, and gauges of flats. The Maximas, by the way, were low tension; light gauge; and pretty mellow - compared to other flats of the time...
2. I don't do- and never have done - "bright". Nothing I ever had to play when I was in a band - and nothing I play now, just for fun - requires "bright". Some music I play sounds best with "mellow"; I have basses with flats that do that quite well. And, of course, I also have basses with flats that do low down, rattle your fillings out. And, when I want "organic & woody"? That's what the tapewounds are for...
3. The one bass I have that deliberately wears rounds, is my '94 Gretsch G6119BO-LH Broadkaster. It wears TIJR 324 Jazz Rounds, because Gretsch, in a fit of... something... decided to put ceramic magnet,
guitar Filtertrons in it; and, in 12 years of trying more strings than I care to think about? The TIJRs are the only strings that make it actually sound like a bass - instead of a big orange guitar. Even then, the bass is brighter than a big hollow-bodied bass has any right to. But, I can live with it; mainly because, if I want to keep the only left handed Gretsch bass I've ever seen - in 35+ years of looking? I have to...
4. My brightest basses with flats? One is a first gen. MIK Danelectro DC59 Pro with 39-96 LaBella 760FX's on it. On the Dano, they give me the characteristic "Dano sound"; not bright, so much as sharp - but they're definitely flatwounds... The other bass is a '95 Alembic Epic, with TI Jazz Flats. I consider TI's to be just to the bright side of the center of the flat wound tone spectrum. With the Alembic's tone controls, it's possible to get the TI's pretty bright; but it's a very creamy, smooth bright. More like a contralto opera singer - instead of the rocker's screech of rounds...
5. As for guitars? Out of the five that I own, the four that I play occasionally, wear flatwounds, too. Italian Dogal strings; either their "Expressive Jazz" flatwounds, or the "Evolution Flatwounds". Pretty heavy ones, too. The 5th guitar? It's a cheap Strat knock-off, that I haven't even picked up in at least 2 years. IIRC, it's wearing EB Slinky 9s...
