Our MM4 bassbuckers were originally produced for my departed friend Jimmy Loyd Rea, USA bassist of great reknown. Alnico 5 pole magnets. The chart shows the response of the pickup with both humbucking coils wired in series but as this is a 4 wire output harness pickup you can switch it from series to parallel or coil cut it down to a single coil mode which will enahance its treble responses.
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