Build your bass lines around supple, mantra-like grooves, a quality that Wobble picked up from steady listening to dub reggae as a teenager. Many of Public Image's trademark songs are built around bare-bones simplicity. For example, the band's debut single, "Public Image," features a four-note bass line (E, B, A, D) that barrels the groove along. Similarly, "Theme" is built on a bass line (E-B, then D, F-sharp and E) that is simply taken up a fourth (A-E-G-B-A) on the neck.
Play without a pick, noting that Wobble prefers to pluck with only finger of his right hand. Like most dub-influenced players, he hovers around the lower to middling frets of the E and A strings to get the deep, dark, throbbing tone that has characterized so much of his work. If your bass has dual pickups, use the one nearest to the neck, and turn down the tone control for the bridge pickup.
Equip your bass with flat-wound strings, whose textures and tones are closer to upright acoustic basses, and treasured among dub, funk and reggae players for this reason. Avoid the more common round-wound strings whose brighter, treblier tone will not get the "impossibly deep" sound that characterizes Wobble's tone.
Avoid the use of distortion, a commodity that proved useful to countless 1977-era punk bands, but one that Wobble saw little point in adopting--even at the time. For recording purposes, bypass the difficulty of miking a bass--instead, run your instrument through a Direct Injection Recording Box to avoid losing any richness in your tone.
Leave enough spaces for the groove to unfold, something that has been a hallmark of Wobble's approach throughout his long career. Wobble's willingness to weave a simple bass pattern behind Public Image-era classics like "Albatross" or "Poptones" allowed his band mates, notably guitarist Keith Levene, to do whatever they liked on top of it. Wobble's present mingling of his dub influences with ambient and world music genres is a logical extension of this principle.