Ionizer 7-String Neck Humbucker Pickup Black. 8-string guitars are Tosin Abasis primary instruments, but hes no stranger to 7-string guitars, and the idea of the Ionizer 7 came up soon after the Ionizer 8 left the drawing board. The Ionizer 7 Neck Model has warm lows and clear highs, and performs like a classic single-coil in split mode. Tech Talk The Ionizer 7 isnt simply the 7-string version of the Ionizer 8. The highs are a little brighter and the lows are a little deeper, to bring out the specific frequency response of the 7-string. Like the Ionizer 8, the single-coil sound is as important as the series humbucking sound, and the split mode is clear and open, with highs that are bright but not thin.