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

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.

Simple Laptop Cooling Stand with 200mm Noctua Fan

MaterialsBuildResults

I assembled the two sides of the stand inside-out to make room for the fan.

I hung the fan from the stand using 2 segments of string.

I angled the fan backwards to make the air flow across the bottom of the laptop.

The USB switch allows me to easily turn the fan off.

Continue to Results

My MateBook X Pro can sustain 2.1GHz on the desk for 5 minutes before shutting off due to VRM overheating (working on solving that right now), but this stand allows it to sustain 2.7GHz indefinitely. As a bonus, I removed the bottom lid altogether and just let the Noctua blow on the laptop’s heatsink directly. No thermal throttling at all anymore. 3.7GHz on all 4 cores. I might just use that when my laptop’s staying on the desk for a long time.

MateBook X Pro, CPU+GPU full load for 10 minutes, on desk.

MateBook X Pro, CPU+GPU full load for 10 minutes, on stand with fan on.

The biggest benefit of using the Noctua fan instead of lower-quality off-the-shelf laptop coolers is that the former is much quieter.

Improving MateBook X Pro’s Speakers

The MateBook X Pro has some of the best speakers on any ultrabook. Unlike most laptops, it has 4 speakers instead of 2: 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. The crisp up-firing tweeters greatly enhance soundstage and imaging. Nevertheless, these speakers are not perfect, and here’s some ways we can improve them.

Analysis in Stock Form

You can refer to this graph to adjust your equalizer setting in the Dolby app, but to get much better sound, read on.

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