The Sony WF-1000XM4 takes another step closer to release with Bluetooth SIG and FCC certifications; new MediaTek SoC with Bluetooth 5.2 onboard rules out aptX or aptX HD support
In February, it emerged that Sony may be working on a new pair of WF-1000X earbuds, presumably the successors to the WF-1000XM3 that Sony released in July 2019. At the time, all we had to go off was a few posts on Reddit, but it seems that the Bluetooth SIG and FCC have now certified the WF-1000XM4.
Both agencies have certified the earbuds as the YY2948, with AK8 the grantee code for the Sony Corporation in the FCC's case. The Bluetooth SIG does not give much away about the WF-1000XM4, beyond that it supports Bluetooth 5.2. By contrast, the WF-1000XM3 supports up to the older Bluetooth 5.0 standard.
Meanwhile, the FCC describes that the WF-1000XM4 has a MediaTek MT2822S SoC, up from the MT2811S found in the WF-1000XM3. Based on The Walkman Blog's findings, the MT2822 has a faster CPU combined with an improved DSP coprocessor. The MT2822 supports up to 24-bit and 192 KHz audio like the MT2811S, but the former utilises Hardware Active Noise Cancellation (ANC) and hardware gain control, among other features.
The FCC has provided a sketch of the WF-1000XM4's charging case too, although possibly only of the top of its lid. While the presence of a MediaTek SoC rules out the WF-1000XM4 from supporting any aptX codecs, leaked box art points to Sony including its proprietary LDAC codec. It is unclear when Sony will release the WF-1000XM4, but the FCC suggests that the earbuds will arrive before September.
Bluetooth SIG & FCC via The Walkman Blog