Did the WF-1000XM4 just pass through the FCC?

So what do we have here, Sony YY2948. The model name gives nothing away, but that label photo looks awfully like a charging case for wireless earbuds. The model number is intentionally left out in the documents, but the product description remains “Wireless Noise Canceling Stereo Headset”.

Sneaky Sony, sneaky.

Update 1

While I initially noticed this difference in the power rating of the unit versus the WF-1000XM3, I did not think much of it. But mirai160525 on twitter pointed out something interesting. The WF-1000XM4 appears to have monopole antenna versus the dipole antenna and they mention that such a change should lower the power use, but the WF-10000XM4 has a higher rating. mirai160525 goes further to suggest that maybe the higher power rating could be for LDAC, no idea, could be. The version of the WF-1000XM4 tested was a prototype where as the WF-1000XM3 was pre-production. I am attaching the antenna information from the reports below.

I also looked at the other WF models, the WF-H800 and WF-SP800N are both monopole antenna as well, the WF-1000X has an inverted-F antenna design. I only information for the WF-XB700 I can find is that it uses a  FPCB antenna. I can attach the antenna design photos if people want me to.

Update 2

The WF-1000XM4 has appeared on the Bluetooth certification site. The YY2948 has been certified for Bluetooth 5.2. Comparing it to the WF-1000XM3, the supported layers are identical, so not sure if the device was tested for LE Audio (unlikely), but the MT2822 which is part of the certification does have the required support layers for LE Audio. The MT2822 certification also confirms that the SoC is an Airoha chip, part of the AB156x family. Photos attached below.

The combined designs, 157713, 163117 correspond to Airoha Hummingbird Duo 5.2 and MT2822 respectively. Perhaps this Bluetooth certification could indicate a much earlier release date and not the late September date if we go by the End of Short Term Confidentiality.

 Update 3

The model has gone through E-postel, but I missed it earlier. So far nothing on any other website, like Anatel, but here is hoping it will show up soon. Apple has said they might face some product shortages, likely due to the current electronic parts shortage globally. Although not sure if this will affect headphones or just high end devices like smartphones and computers. Hopefully there will be no delay in the release of the WF-1000XM4 but even if announced relatively soon, I suspect the model would not go on sale for another month or 2.

Update 4

I rarely update these that late, but I was finally able to find Industry Canada’s website for their certifications. Unfortunately no new information from here, the RF exposure is less than the WF-1000XM3 (0.95 W/Kg), now rated at 0.36 W/Kg.

For comparison, the WF-1000XM3 numbers.

End of Update

Clearly we are looking at some new wireless earbuds from Sony. In the documents, the right part is only tested since both the left and right are the same as mentioned in the FCC filing:

* Only right part was representatively tested by client request since left part and right part are the same specification.

Likewise, a charging case is mentioned in the label document, so we are definitely looking at a wireless earbud headset here.

Since headset part to be applied is small and there is no space, it is described in charging case and manual

But is this the WF-1000XM4? Unless Sony has another wireless earbud headset coming, my guess is yes, this is the WF-1000XM4. Digging deeper into the documents reveals the new Bluetooth SoC being used for the new model, different than the Mediatek MT2811 found in the current model

So we are looking at a new Bluetooth SoC, MT2822S in the new WF-1000XM4. Similar software was used on the WF-SP800N in its FCC filing, but with M2811S_BT_Test instead. The WF-1000XM3 also had MT2811S_BT_Test as well in its FCC filing, but since I had no knowledge of the Mediatek MT2811 back then, I had no idea what MT2811 was. When 52Audio posted their teardown of the WF-1000XM3, did I then only realize this software was in reference to the Bluetooth SoC.

Mediatek MT2822S

So what is the MT2822S? I believe this is a rebranded Airoha AB1568. My reasoning is based on 2 pieces of information, first, a post on reddit by AMD_Fanboy_Wavpro who confirmed the AB1568 and MT2822 are the same; second, a linkedin account which mentions the AB1568 and MT2822 as the same chip. This individual works at Airoha.

The full specifications of the AB1568 are up on Airoha’s website here and one can compare it to the MT2811/AB1552x here.  Here is a quick table comparison of the 2 Bluetooth SoCs, some aspects like power management are a mystery to me.