DIFFERENT TYPES OF BASS STRINGS
Both the tone and feel of a string are strongly affected by the material used for the cover wire.
This is the reason why stainless steel produces a very bright sound and nickel, a softer material,
produces a warmer sound. Usually, the harder the material, the brighter the string, the more abrasive the feel
sensed by your fingertips and the more fret wear.
There are at least three types of winding techniques used for bass strings: round wound strings, half round wound strings and flat
wound strings. The difference is in the profile of the cover wire.
Not only different kind of strings will deliver different tones, they will also have an impact on frets and fretless fretboard
wearing and on the "feel" we sense under our fingers.
For what concerns the electric bass, steel strings tend to sound brighter while nickel's tone tends to be slightly warmer with an accentuated mid frequencies response. Nickel strings also deliver a smoother feel at touch which some like most, as compared to stainless steel strings.
For those reasons some of us prefer stainless steel for slap and nickel for a more "rock" and "vintage" tone.
Fretless bass tone is also deeply influenced by the type of string used.
If a more "upright" tone is required we suggest the use of flat wound strings which offer a better feel at touch and a deeper less bright tone Sound wise, half wound strings will place themselves half way between the two previously mentioned types.
In the acoustic bass (for an unplugged gig) it is possible to use Nylon strings: nylon strings usually feature a nylon core covered with bronze or nickel: please note that nor bronze nor nylon are captured by the magnetic field of the pickup. Therefore they will only work with piezoelectric pickup.
HINTS AND TIPS
When mounting bass strings we must be careful not to twist the strings when tuning or this will deteriorate them and their sound. The process is well explained in this video:
Round wound strings are recommended for those who looks for a "solo" fretless tone with long notes and that classic "brass" effect which requires an almost straight neck and slightly higher strings to be achieved.