Lo-Z: Let’s Clear a Misconception

Allow me to clear up a very common misconception about Lo-Z (low impedance) pickups. This should probably be in a FAQ, and so I transformed this “issue” into a question. It’s quite frustrating to have to explain every time, so I will provide my answer afterwards, once and for all. Next time I see something similar, I’ll just provide this link.

Q: I do not have bat ears. Why will I want a pickup with a frequency range that extends beyond 20kHz? People do not want “high fidelity” pickups. They want the tones they hear on a record. And that is definitely not “high fidelity”.

A: There’s an obvious reason why an artist paints on a white canvas. Gesso is used to prime the canvas before use. It is a white paint mixture consisting of a binder mixed with chalk, gypsum, pigment, or any combination of these. You have a consistent base where you paint over with whatever colors you choose.

The same reason holds for guitar pickups. A full-range pickup with uniform frequency response is like a blank white canvas. You do not typically use full-range pickups as-is, although there are situations where you might want to. Such situations are rare — as rare as completely white paintings. No, what you do is paint over the canvas! You use tone-shapers, EQs, resonant filters to get the desired tone/color.

Traditional high impedance (Hi-Z) pickups have their own baked-in character. You will have to replace the pickup to get a different tone — defined by the pickup’s frequency response and characterized by its resonant frequency, which typically starts to fall off around 2-6 kHz. The Lo-Z XR and Nu pickups, on the other hand, allow you to change the pickup’s tone anytime using post EQs.

Here’s the actual measured frequency responses of various pickups in the wild, vis-à-vis the Nu pickup (blue line near the top):

If you want the tones you hear on a record, say, for example, a Stratocaster pickup, what you do is insert an EQ that follows your desired frequency response curve, before anything else. The greatest advantage of pickups with a relatively flat frequency response, such as the Nu or XR pickups, is that it is straightforward to emulate other pickups. You just need a 2nd order parametric EQ with controls for 1) The resonant frequency and 2) Q. This table (by Helmuth E. W. Lemme) can help you get started: Resonant frequencies of some well-know pickups. You might also want to read up on his article about The Secrets of Electric Guitar Pickups, while you are at it.

Further Reading