Analysis in Stock Form
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 up-firing tweeters are crisp and enhance the soundstage and imaging a lot. Nevertheless, these speakers are not perfect, and here’s some ways we can improve them.
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.
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
The MateBook X Pro’s speakers have a pretty awful distortion at around 511Hz. Both my unit and another at a Huawei store have this problem, so it’s most likely a design flaw instead of a defective unit. The cause appears to be the bottom of the speaker enclosure vibrating against the laptop’s unibody shell, and the speaker’s screws vibrating as well.
To reduce the distortion problem, I removed the foam seal around the speaker drivers. Now, the bottom lid no longer presses the speaker against the unibody.
Moreover, I also put a thin strip of sponge under the speaker to separate the resonating components.
Per my ear, this mod successfully eliminated the distortion except at absurdly high volumes.
Other than a reduction in low treble, the frequency response stays intact. Very fortunately, this mod doesn’t reduce bass.
Frequency Response Correction
I used Room EQ Wizard to generate a set of equalizer parameters that flatten (±2dB) the frequency response down to about 110Hz, which is the point beyond which the total harmonic distortion exceeds 10%. I used a high-pass to filter out the distortion-heavy frequencies below that. I refrained from boosting the top treble too much and gave it a smooth roll-off instead.
This is how the correction filters look in Equalizer APO. Notice that correcting the frequency response (especially extending the bass) requires some sacrifice of volume. So, you could have an aggressive correction and a big volume reduction, or preserve volume by using a conservative correction. Perhaps you could store both of those EQ curves and switch between them depending on what you want, but that’s a hassle. What you this could happen automatically? What if the laptop automatically gave you the best tonality achievable at whatever volume level you set at any time?
DyanmiQ, implemented in Equalizer APO, is an algorithm that intelligently adjusts the level of bass extension according to the real-time volume level.