Bought them for a Fender Jazz fretless with active pickups and I couldn't be happier. Exactly what I was looking for. Deep, low growly bottom end and very well defined. Certainly not very bright. If you're looking for bright, you probably wouldn't be looking at flatwounds. But for flatwounds, they do sound a bit livelier than ones I've used in the past from brands such as Fender and GHS. But for the deep, low, growly sound I was looking for from my fretless bass, these are perfect.