I didn’t want to buy the official “wireless upgrade module” which KZ sells for their ZS5/6 and other compatible IEMs (There I said it! ).
Anyway, a LOT of people were asking about the module sound quality and without hearing one I couldn’t actually help them out. I’m totally against giving advice on gear I never heard.
Also, keep in mind that I won’t review the microphone because I won’t use it.
So the module is basically a 4.2 Bluetooth receiver and audio amplifier that connects directly to the terminals of compatible IEM shells. So you are limited to use this module only with compatible KZ earphones or gear that uses the dual pin layout KZ uses.
You got the typical switches that I don’t really talk about, all in a cheap ABS enclosure, but for the price, I shouldn’t really complain. Cable also feels cheaper than the stock cable KZ ships on their cheapest IEMs models.
This thing runs on an inbuilt rechargeable battery that should last about 3 or 4 hours on a 1-hour charge, their values not mine. (With the ZS5 V1 blasting at high volume the battery lasted less than 2 hours so keep that in mind.)
It supports aptX audio codec, Hands-Free Profile (HFP) 1.6, Headset Profile (HSP) 1.2, Audio/Video Remote Control Profile (AVRCP) 1.4 and the Advanced Audio Distribution Profile (A2DP) 1.2 up to 10 meters, again their specs not mine.
Now to the sound quality, well this thing can go loud and I mean LOUD!
Ok, above a certain point the distortion kicks in, but believe me this little thing can drive my ZS5 to unhealthy levels of sound pressure.
You’ll lose a lot of detail and bass for wireless convenience, especially bass.
The ZS5 bass on this module sounds muddy/lose and doesn’t go as deep as it should, also the detail on the highs goes downhill. I’m comparing this Bluetooth module amplifier with the amplifier of my Sony Walkman NWZ-E584 so it’s a fair review. For most non-audiophile users this thing will rock their music world.
I didn’t notice any hiccups on the Bluetooth connection from my Sony L1 (2017) smartphone.
Anyway if you need a convenient way to enjoy music when running, doing some chores at home or garden this module might be a nice way to achieve that, it pairs well to the phone and goes loud if necessary.
This Bluetooth module needs a better audio amplifier, not a louder one but something that can really control the IEM drivers properly, until then keep using cables and save mother earth some disposable tech, because believe me when this module battery kicks the bucket you will not replace it for sure, mostly because it’s not worth it.
There, I respect this little Bluetooth module for daily background music, for anything better than that forget it, even a cheap ass cable does a better job controlling the IEMs.