A $50 S-Tier True Wireless Earphone??

Moondrop's new Pudding True Wireless earphone ($50) wins serious points with me for the name alone, but its out-of-the-box performance is a much more complicated story.

By default, the Pudding actually sounds particularly rough for me. It is, like many IEMs, dominated by a harsh, scratchy treble presentation due to length mode resonances in the low treble that arise due to my ear canal being particularly long.

However, despite an initially unfortunate default tuning, Pudding might still be one of the best budget wireless releases on the market—all because Moondrop included true Parametric EQ (PEQ) inside their app so that end-users could address the resonances that will arise for them.

The Single-line Measurement Trap: Length Mode Resonances Matter

To understand why the Pudding sounds harsh by default despite looking fantastic on paper, you have to understand in-ear length mode resonances.

Whenever an earbud is inserted into a human ear, the sealed air volume between the nozzle and your eardrum is functionally a very tiny room. Like any room, if there are parallel surfaces, there will be standing waves that arise based on the distance between the two surfaces. With IEMs in ear canals, the distance between the IEM's eartip and the eardrum creates a standing half-wave resonance (a resonance corresponding to half of the length of the ear canal), typically showing up anywhere between 5 kHz and 10 kHz.

On standard measurement test fixtures with typical 8 kHz insertion alignment, the Pudding looks great because the fixture & methodology only models a single, static ear canal geometry.

And this is because Moondrop has specifically tuned a digital EQ band into the Pudding at 8 kHz, because most people publishing measurement data will purposely insert their IEM into their measurement microphones to produce an 8 kHz peak. This is an unrealistically homogenous display condition, and this is not at all how the product will actually respond in a given person's ear canal though.

On real human heads, ear canal sizes, lengths, and IEM insertion depths will vary wildly, which means the smooth treble seen above simply will not occur.

If you have a larger or longer ear canal, that resonance hits hard—showing up right around 6.8 kHz on my head, and you can see that right after this that the IEM has a very narrow/sharp dip at exactly 8 kHz.

This creates a grating, sibilant treble spike that quickly cascades into a dip, and this ruins what would otherwise be a perfectly acceptable bass and midrange balance for a $50 device and makes it very harsh for me.

But thankfully: it can be fixed.

God Bless Parametric EQ

Ear canal resonances aren't a unique flaw of the Moondrop Pudding; they are a fundamental acoustic reality for almost every in-ear monitor in existence. What is unique for $50 is that, even if Moondrop kind of flubbed it a bit by trying to neuter this peak statically, with a single EQ point, Moondrop gives you the exact software tools required to solve the problem yourself if you want to, and this is of course where we need to talk about their Parametric EQ available in their app.

What's great about this software implementation is that end-users can run a free web-based tone generator sweep on their phone to identify the exact frequency where their specific "system" (the shared system between IEM and eardrum) produces peaks.

Once you pinpoint that harsh spot, you can open the Moondrop app and use the Parametric EQ to manually notch out the resonance. While the app carries a few quirks—limited positive gain headroom (+3 dB) is a bit annoying considering I have to undo the 8 kHz dip that Moondrop saw fit to bake into the response here—and a slightly misleading visual interface, the ability to cut your specific acoustic spikes transforms the Pudding into a spectacular-sounding earbud.

Conclusion

Outside of its EQ flexibility, the rest of the hardware package is standard budget fare. The Active Noise Cancellation is basic, offering just enough attenuation to dull street traffic while walking outside. The transparency mode delivers sufficient environmental awareness for outdoor hikes, even if your own voice still suffers from a bit of an occluded "talking in a barrel" effect when speaking.

You shouldn't buy the Moondrop Pudding expecting class-leading ANC or luxury materials. You should buy it because it offers Parametric EQ with 8 bands on top of a bass & midrange tuning that is already very solid, and does so at an accessible $50 price point. We're neck deep in IEMs that do alright in the bass and midrange but completely flub the treble, but the difference with Pudding is that you can actually fix the treble... and that is, arguably, the difference between any ol' true wireless earphone, and an S-tier one.