KZ AZ09 Pro Review: Fundamentally Good but Fatally Flawed

Review written by @Fc-Construct

Review unit provided by KZ

Ever wished you could have true wireless convenience with your wired IEMs? There’s actually a number of products out there that let you do just that, including the TRN BT20S Pro and FiiO UTWS5. While these aren’t a true 1:1 adaptation, you can get fairly close in terms of a TWS setup. However, these sort of TWS modules are often plagued with a number of issues such as a high floor noise or an unstable BT connection. On top of that are often a number of features that manufacturers may try to incorporate such as IPX waterproofing, ANC, or an accompanying app with varying success.

This is a companion discussion topic for the original entry at

Hi @Fc-Construct , thanks for the detailed review. This finalize my purchase options. Since I have KZ ZSN Pro and I wanna to upgrade it into something wireless. However, your mention of Flaw really brings a difference. The fact is I now have an option to purchase a new B type pin connector which is the one you were searching for. I think this means it’s fundamentally good … Period?

Sorry, I can’t really comment on it as it’s been a while since I’ve looked into the KZ connector types. 2-pin connectors are all sorts of confusing so I don’t want to accidentally mislead you here. As well, I don’t recommend KZ any more as they have a tendency to meaningfully revise products after release so I can’t be sure that what I reviewed is the same item still on sale.

Oh yeah I don’t even know they like to revise the products. I see, but if I don’t buy AZ09, what other kind of Bluetooth adapter (with similar shape functionally as AZ09) that I can use to upgrade my KZ ZSN Pro?

I haven’t been up to date on wireless adapters so I can’t comment too much. But my understanding is that most of the other options would be a good bit more expensive. However, if your concern is only the ZSN Pro, the AZ09 Pro would work since both are KZ products. It’s only if you want to go with a different IEM in the future that you might have issues. As mentioned, I don’t recommend KZ anymore out of principle but that said, it’s still a product that will suit your needs, provided nothing has changed.

I understand, thankyou for your time and your reviews. I too, think the option for this price range is hard to find. Although yeah in future if I actually then consider Moondrop products or other I probably need another kind of adapter :joy:.