Sony WH-CH720N Teardown by 52Audio

The WH-CH720N is a solid headset, offering good noise cancellation, sound quality and if you can find it, a good price. Let us look at the teardown from 52Audio and see what is hiding underneath all that plastic.

Amazon US - WH-CH720N

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 First me must remove the ear cushions. Unlike the WH-1000XM5, the cushions on the cheaper WH-CH720N just slide off the plastic edge. This is like the previous model and the WH-CH520.

This is good and bad, on one hand, you will not break any plastic tabs on the cushions, but on the other hand, the material can rip if you are not careful when taking them off, or putting them back on.

I compared the ear pad material between the WH-1000XM5 and WH-CH720N, and the higher end WH-1000XM5 has much better material. the pads are smoother and feels more premium. The WH-1000XM5 ear pads also cut out noise better and form a tighter seal around the ears. This has a pretty big impact on noise cancellation performance.

With the cushion over off, we can see the 30mm driver. the feedback NC mic can be seen in the center of the driver. The WH-CH720N still uses regular copper wires for the connection. The WH-1000XM5 has moved to a ribbon cable.

If we compare the new model to the older WH-CH710N, there are some design differences.

Sony WH-CH710N

The old model has the feedback NC cable exiting through the bottom where as the new model has the same wire from the side. The newer model also has the entire surface sunken down creating a deeper area and space for the ear. Finally the mesh surrounding the driver is also slightly thinner. 

The WH-CH720N have no foam inside to cover the driver like the WH-1000XM5. This means only the mesh from the ear cushions will keep dust and dirt out, so in order to maintain the headset, it would be best to keep the mesh clean and dirt free.

Removing the NC mic, we can see it is an electret type microphone.

This is an unfortunate revelation. From the FCC filings, it almost looked like Sony used MEMS mics, but it seems they have gone the other route and went for electret. I am sure electret mics have some advantages over MEMS mics, but recall the issues WH-1000XM4 owners had with their feedback NC mics. The high pitched noise. This was due to moisture getting into the mic and damaging it. MEMS mics are a lot more resistant to moisture and should be less susceptible to this problem. And yes, the WH-1000XM4 uses electret mics for their NC mics, only the voice microphone array uses MEMS mics.

Will moisture be an issue for the WH-CH720N and the electret mic? Good question. Hopefully it will not be an issue but in high humid areas, any problems could arise faster.

Moving on, removing the screws, we can detach the driver housing.

On the right side, we have the battery along with the main button controls. Zooming in we can see something like glue around the feedforward mic housing. I suspect this is to keep any moisture from getting inside the headset.

We can remove the driver cover to reveal the back of the driver unit. The cover is help in place by 3 screws. Looking at the inside, it would technically be possible to fit a larger 40mm driver inside.

There is a rubber seal around the driver cover edge.

Removing the driver, we can see it is ~30mm like in the specifications from Sony.

The design of the driver is a lot different to the 30mm driver in the WH-1000XM5, so while they are they same size, they are not the same units. The WH-1000XM5 driver can be seen below.

Sony WH-1000XM5 driver

Here we have the button control PCB from the right side. The battery also connects here, and is connected via a connector, so it can be replaced by the user.

1. Feedforward mic connection
2. Battery connection
3. Right side driver connection
4. Feedback mic connection

Next up we have the battery. It is manufactured by Chongqing VDL Electronics Co. It is a 520mAh 2.0Wh Li-ion, rated at 3.85V. The model is 722428.

The battery comes with a small battery protection board which has a lithium battery protection chip, MOS tube and thermistor, which are responsible for the battery's overcharge, overdischarge, overcurrent, overheating and other protection functions, according to 52Audio.

There does appear to be room for a larger battery, but it seems the newer model is a lot more efficient than the previous one which had a much larger battery in size and capacity.

Opening up the left side, we have the main PCB taking up the entire interior area.

Here is a closeup of the main PCB.

We can actually see the some of the labels of the wires coming from the right side. The lower left corner of the PCB has connections for the feedfoward NC mic and the voice mic. The bottom right of the PCB is the wireless antenna. In the top left we have the speaker and feedback NC mic connections.

Zooming in on the main chip, we can see that it is a Mediatek MT2822MA.

If the MT2822 sounds familiar, that is because it is the Sony V1 chip. Sony did mention the V1 in the WH-CH720N press release, so it is good that they are embracing marketing terms for components in their tech.

And with that, this concludes the teardown. If people want me to write up a review of my WH-CH720N, I am more than happy to, but there are other reviews out there already, so it might not be necessary.

Check out the full 52Audio teardown for more photos.

Amazon US - WH-CH720N

Amazon Canada - WH-CH720N

Amazon UK - WH-CH720N

Amazon DE -  WH-CH720N