Category Archives: Tech Stuff

Huawei Revises MateBook X Pro with Speaker Distortion Remedy

Previously, the Huawei MateBook X Pro’s speakers would produce distortion because they rattled against the laptop body. As shown in this unit purchased in November, Huawei has addressed this issue by putting small pieces of foam underneath the speakers. Is this because they saw my original post, where I both pointed out the issue and introduced this very solution? We may never know.

You’re Probably Doing 3D Printing Tolerancing Wrong. Here’s a Better Way.

Do you use 3D printing to make functional parts? Do your printed parts have slight dimensional errors, such as undersized holes? It is essential to take care of this if you use your FDM 3D printer to make precise or functional parts. Here’s the easiest and most elegant fix, using nothing but your slicer and a caliper.

Because the extruded molten plastic gets squashed by the nozzle and also flows outward toward the sides, everything you print is fattened, creating overall oversized prints and undersized holes.

Fortunately, there are ways to fix this flaw. First, I would recommend against these methods, if you currently use them:

Bad methods
  • Compensating by slightly changing the values in CAD: this is cumbersome if you use different printers or have collaborators, and problematic if you work with assemblies in CAD.
  • Changing the size in the slicer: FDM 3D printers generally have undersized ID and oversized OD, so enlarging or shrinking the size is bound to reduce one problem while worsening the other.

The Elegant Way: Horizontal Expansion

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HE400i EQ Correction using Rtings Data

Introduction

I found a frequency response measurement of the HE400i that is more accurate than the ones I previously used in my equalizer settings. I discovered a way to extract the graph data from Rtings.com. Rtings.com has measurements of lots of headphones, and their methodology is one of the most accurate. So, I imported their data into Room EQ Wizard and created an equalizer profile to correct the frequency response of my HiFiMan HE400i.

Measurements and Correction

I came up with the filters manually. I’m choosing not to boost the troughs or over-correct the treble to prevent side effects that arise when any particular listener’s ears don’t exactly match this graph.

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Here’s Why MateBook X Pro Charges Slowly

Forget CPU and GPU thermal throttling — charge rate throttling is now a thing.

Exposed charging circuit with shielding cover peeled off. Plugged in, CPU idle.

  • The charging circuit doesn’t have enough cooling and tends to overheat.
  • Since the charging circuit and the CPU use the same heatsink, heat from the CPU gets dumped onto the charging circuit, making it even hotter.
  • The charging rate is temperature-dependent, but the charging circuit doesn’t seem to have a temperature sensor, so Huawei probably went super conservative about protecting the charging circuit and modeled its temperature after the CPU temperature.

Therefore, even when the CPU is a little bit warm, the charging rate thermal-throttles.

I will discuss solutions to reduce this as part my throttling elimination project.

Also, the recent BIOS updates seem to have slightly improved the charge rate.