The Audio Technica ATH-WS99BT is a newer Bluetooth version of the Audio Technica's ATH-WS99 wired over-ear headphones.
These Bluetooth headphones come with AptX encoding built-in for great audio quality even being wireless headphones.
Overall, the sound quality offered by these headphones is great. Similar to the wired counterpart, the emphasis is on bass. Let me review the ATH-WS99BT and also explain how it compared with the wired version.
At the end of the review, you'll be able to accurately determine whether to go for the wired headphones or the wireless version of the headphones.
Let's get started with the review.
Audio-Technica ATH-WS99BT review
Build and design
Right out of the box these headphones seem quite heavy, this may be due to the big 53mm bass-centric drivers present in these Bluetooth headphones.
The headphones are well-built and made up of premium plastic and they feel solid with no rattling feeling.
In the left earcup, you've got the 3.5mm optional headphone jack and also the USB post for putting your headphone for charging.
And also the volume control buttons, Bluetooth buttons, and the power button is present in the left earcup itself.
The package also comes with a 1.5m cord that you can plug into the 3.5mm port on your left earcup as I told you earlier.
The cord comes with volume/power controls and also an omnidirectional inline mic for you to use the headphones with your smartphone.
This is a nice addition that lets you to easily convert your wireless headphones to wired ones to sound a little bit better that you can barely tell without an audiophilic ear.
Sound quality
These are bass-centric headphones. Obviously, the bass on these headphones is really good.
Coming to the mids, the vocals of the artists also turn out to be clear and there's nothing to complain.
When it comes to treble, it's balanced with no harshness.
Although these headphones are marketed to be great when it comes to bass, the sound profile is very balanced. Unlike other bass marketed headphones (like Beats and JVC), the bass does not overshadow the details in the music.
The bass only comes out when the music demands it. In this regard, the Audio-Technica has managed to hit the sweet spot between the performance of bass and also the balanced sound quality.
The sound quality of ATH-WS99BT is no different than the wired ATH-WS99 version. You can barely tell the difference in the sound quality of these two headphones, in spite of this being the wireless variant.
The sound signature is really similar to the M50x, but there is an emphasis on bass.
With the impedance of 37ohms and the sensitivity of 105dB/mW, the sound can get really loud depending upon your volume levels.
These are not noise cancelling headphones, but does the job of keeping out ample of ambient noise out pretty well due to the closed back design.
Comfort
The earcups padding is soft and quite small. For some people, that too with large ears, they find sweaty after wearing it for hours.
In that case, lots of people have found these ear pads from Brainwavz HM5 or the Beyers are big enough and perfectly fit the ATH-WS99BT.

You also need to be aware that the change in the padding may alter the sound profile a bit, but well, if superior comfort is the first choice for you, then replacing the pads may be a viable option for you if you've got large ears.
Apart from the small issue I described above the headphones are super-comfortable. You can wear these on for hours, without causing any fatigue.
The battery life is decent with 6 hours of Bluetooth playback. When you run out of battery, you can plug in the provisional cord and convert the headphones to wired headphones and you are good to go.

Pros and cons
Pros
The provisional cord comes with a mic.
Cons
- The earpads are pretty small for big ears
- The buttons on the left earcup are small and you end up hitting the wrong one
Bottomline
Overall these are great headphones for the price. There's nothing much to complain about it. If you are a fan of M50x, and wanted some bass boosting effects alongside, the ATH-WS99BT is the way to go.
If you want the cheaper wired variant of these headphones with an exact same sound profile to consider saving some bucks going for ATH-WS99.
If you are eager to witness the audiophilic sound in the wireless mode, the ATH-WS99BT won't disappoint you.
Hope you loved my Audio-Technica ATH-WS99BT review.