Sony WH-1000XM4 teardown by 52Audio

I was not expecting a teardown so quickly of the Sony WH-1000XM4, but 52Audio.com has delivered once again, so time to dive in, see what is new and compare it to the WH-1000XM3

I will not focus much on the exterior changes, so if anyone wishes to compare the exteriors, check out the links here (XM4, XM3). All photos are courtesy from 52Audio, check out their full teardown here on 52Audio.com.

The first notable difference in the build is the inside plastic holding the driver and the sponge surrounding the driver. In the XM4, the plastic is one piece and the sponge does appear to be slightly bigger and fills out the space much more than the sponge in the XM3. This should help with passive noise cancellation.

Looking at the XM3 for comparison. The sponge has less material than the XM4 sponge.

Here we can see the interior plastic which holds the driver. In the XM4, it is made out of 1 piece, where as the XM3 has 2 pieces. Simplifying the design to 1 piece should help with rigidity, weight, and production. In addition, the design of the plastic is also quite different on the XM4 versus XM3. So while the XM4 and XM3 look almost identical on the outside, the interior is a different story it, as expected.

Next up is the feedback microphone located inside the headphones. The FB microphone is now covered by a plastic piece instead of just tape. The plastic cover affixes to the main unit with clips. I wonder why this design change has occurred, perhaps the tape was peeling off and the NC microphone was coming free?

Likewise the Feedback NC microphone has a different orientation on the XM4 than XM3. On the new XM4, the microphone is now perpendicular to the driver, where as on the XM3 it was parallel. I am not sure why this has been changed, perhaps this microphone is also involved for voice and noise cancellation during calls? Could this be the extra mic? Would love to hear Sony’s reasoning for this change. If anyone has any ideas, please leave a comment below. Other than that, it looks like the microphone is the same.

Opening the right side reveals the battery and touch sensor. The touch sensor looks identical but upon closer inspection is a bit different. Around the touch sensor cover is a rubber seal, same a before. A small change, but significant, is the use of a ribbon cable which connects the small battery/touch sensor PCB to the main board. This helps with production since on the XM3, the wires were soldered to the board which takes more time than just plugging in a ribbon cable. As well, repair’s should be quicker.

Another design change is the FeedForward NC microphone opening, now looking a lot better than on the XM3. This may not be something big, but it looks more premium and probably functions better.