HMX Bad Sweetheart 45g

Quick Summary

The HMX Bad Sweetheart 45g is a light, factory-lubed linear that delivers exactly the kind of glassy, effortless keystroke HMX has built its reputation on. With a 45g actuation, a gentle 50g bottom-out and a rounded sound signature, it’s a comfortable daily driver aimed at typists who want smoothness over drama. If you like a switch that simply gets out of the way, this is an easy recommendation.

Specs and Feel

This is a clean linear from top to bottom, with no hint of a bump, just a uniform glide down to a soft landing. Force is light at 45g actuation rising to a 50g bottom-out, so it stays comfortable through long stretches of typing or gaming without ever feeling heavy. Travel is slightly shorter than MX-standard at 2.0mm pre-travel and 3.8mm total, which gives the press a snappy, responsive return.

The standout trait is smoothness. The PA12 stem riding in HMX’s P4 housing produces the near-frictionless travel the brand is known for, and out of the box there’s effectively no detectable scratch. Stem wobble is well controlled in both directions. It is not the tightest switch ever made, but tighter than most at this price. The T5 spring keeps the rebound crisp and consistent. Sound is rounded and full rather than sharp; the P4 bottom housing dampens the bottom-out into a deeper, mellower note that suits a foamed, gasket-mounted build nicely.

Tuning

There’s little to do here. The factory lube job is even and the switch performs at its best stock, so most builders should mount and type. If you want to chase the last bit of refinement, films aren’t necessary given the already-low wobble; at most a light spring swap to a longer spring can add a touch of pre-load, but it’s optional.

Verdict

Buy it. The Bad Sweetheart 45g is a low-fuss, high-smoothness linear that punches well above its budget price, and at roughly thirty cents a switch it’s hard to argue with. It’s a great pick for anyone who wants a light, refined typing feel with a warm sound and no modding homework. Enthusiasts hunting for a heavier or more aggressive linear should look elsewhere, but as an everyday smooth linear it’s a quietly excellent choice.