I've been playing bass about 30 years. For most of that time I've been using D'Addario Chromes flatwounds on Fender Jazz style basses, but I had started to get annoyed by the slightly metallic edginess to the sound, and after reading lots of reviews of other flatwound strings, thought I would try some out.
At first I tried the Thomastik-Infeld Jazz Flats but hated how rubbery and low tension they felt. The set I had also had different windings on different strings, leading to uneven tone across the strings.
Next I tried the Pyramid Golds, they sounded and felt great, and the tension was good, but in a week I had somehow managed to break the D string, something I have never done at any other time on a bass guitar. I did replace it once, but it put me off them and my interest was piqued by the La Bellas.
So I put these on, they are the largest gauge bass strings I have ever used, and possibly the highest tension, but the beautiful thing about them is that they don't really feel that high tension and are a joy to play. The strings feel lovely under the fingers, and after a couple of weeks of playing in, the tone is to die for. Very evenly balanced in tone and feel across the strings and fretboard. Just what I wanted. Very thumpy, bassy and percussive, with very few overtones and sustain.
No negatives I can think of, other than they are a little pricey, but they will probably stay on my bass forever now. Maybe not for someone looking for bright/zingy/sustained tones. Think old school thumpy Motown stuff, or Reggae bass lines etc. Highly recommended!
