Category Archives: Tech Stuff

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

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.

MateBook X Pro Bottom Creaking Fix

The Problem

The bottom of the Huawei MateBook X Pro makes a creaking or squeaking noise when you lift the laptop by a bottom corner.

The Cause

The noise is not caused by the laptop’s body but by the crinkling of the battery’s wrapping. You are exerting pressure on the battery area, slightly bending the bottom panel and pressing the battery.

The Solution

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Improving MateBook X Pro’s Speakers

Measurements in Stock Form

The MateBook X Pro has some of the best speakers on any ultrabook. There are a pair of up-facing tweeters under the speaker grill and a pair of down-facing woofers on the laptop’s bottom corners. These speakers are not perfect, and how’s some ways we can improve them.

The brown line is the frequency response, and the others are the harmonic distortion levels.

You can refer to this graph to adjust your equalizer setting in the Dolby app. You can also right click and download my Room EQ Wizard file to generate an equalizer setting for Equalizer APO.

Audio Drivers

Blue is Microsoft driver, purple is Realtek driver.

Switching to generic Microsoft audio drivers in Device Manager disables the tweeters and makes the sound fecal. Don’t do it. Keep the default Realtek drivers.

Distortion Problem and Possible Fix

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