You can almost predict what is going to happen.
Someone watches a Stray Kids music video for the first time.
They are enjoying the choreography. They notice the rappers. They comment on the production.
Then Felix opens his mouth.
The video stops.
“Wait… what?”
“Who is that?”
“Is that really his voice?”
Sometimes they rewind.
Sometimes they immediately ask which member he is.
And sometimes, that tiny moment becomes the beginning of a much bigger journey into Stray Kids.
Among STAYs, there is even an unofficial name for this phenomenon:
The Felix Effect.
What Does “Felix Effect” Mean?
The “Felix Effect” isn’t an official JYP Entertainment term.
It is a fan expression used to describe a familiar pattern: someone who knows little—or sometimes nothing—about Stray Kids hears Felix’s unusually deep voice, becomes curious about him, and then starts exploring the group.
And there is plenty of anecdotal evidence behind the nickname.
Reaction compilations built specifically around people hearing Felix’s voice have attracted huge audiences. Fans in reaction-video comment sections repeatedly say that watching newcomers discover his voice is one of their favorite parts of introducing someone to Stray Kids.
Even in 2026, new reaction videos still explicitly refer to the phenomenon as the “Felix Effect.”
So why does it work?
The First Shock Is the Contrast
Felix doesn’t necessarily look the way first-time viewers expect that voice to sound.
That contrast matters.
A new viewer sees his face—and then hears an unexpectedly low, resonant voice.
The brain needs a second to connect the two.
That is why one of the most common reactions isn’t simply:
“I like his voice.”
It is:
“Is that really his voice?”
Felix himself has talked about how naturally deep his voice became during puberty. In an interview with W Korea, he recalled that both he and his family were surprised by how low his voice had become when he was around 12.
He has also described his deep voice as an important part of his identity as a performer.
So the surprise that first-time listeners experience isn’t an accident created only by studio effects.
It is connected to one of Felix’s most recognizable natural characteristics.
Then Came “God’s Menu”
If there is one song most closely associated with the Felix Effect, it is Stray Kids’ 2020 breakthrough track “God’s Menu.”
The song was released on June 17, 2020 as part of the album GO LIVE.
Near the middle of an already aggressive, unpredictable song, Felix suddenly delivers one of its most recognizable moments in his signature low register.
For many first-time listeners, everything stops there.
Reaction videos repeatedly show the same behavior:
pause,
confusion,
rewind,
then:
“Who is that?”
There is even a large subgenre of Stray Kids reaction content built around capturing exactly this moment.
And “God’s Menu” was important to Stray Kids for reasons beyond Felix.
Felix himself later described the song as a turning point for the group because it clearly showed Stray Kids’ own musical identity.
That distinction matters.
The Felix Effect didn’t happen in isolation.
His voice landed inside a song that was already designed to sound unmistakably like Stray Kids.
The Effect Didn’t End With “God’s Menu”
Then came “MANIAC.”
Years after “God’s Menu,” the reaction remained remarkably familiar.
In one first-time reaction we examined, a listener hears Felix and immediately remembers the same voice from an earlier Stray Kids song:
“What on earth? That is so cool.”
By the end of the reaction, Felix is one of the members they can remember and identify.
That pattern appears elsewhere too.
Some fans describe hearing MANIAC and wanting to know who had “that voice.” Others say Felix’s voice was the first Stray Kids voice they could recognize before they knew all eight members.
This is what makes the Felix Effect more interesting than simply saying:
“Felix has a deep voice.”
The important part is what happens after people hear it.
A Voice Can Become a Search Button
Think about the sequence.
A casual viewer doesn’t need to know anything about Stray Kids.
They don’t need to understand Korean.
They don’t need to know what STAY means.
They don’t even need to be a K-pop fan.
They only need one moment strong enough to make them curious.
Voice → surprise → “Who is that?” → Felix → Stray Kids → another song.
Felix effectively becomes a human search button.
And this may help explain why his voice works particularly well in short-form video, reaction content and first-listen experiences.
You don’t need three minutes to understand what makes it unusual.
You can hear it in seconds.
But Felix Alone Doesn’t Turn Someone Into a STAY
This is where the story becomes more interesting.
The Felix Effect may open the door.
But Stray Kids still has to keep the listener inside.
When we looked through first-time Stray Kids reactions, newcomers quickly began noticing other things:
Changbin and Han’s rap,
Hyunjin’s performance and visuals,
Bang Chan,
the group’s unusual song structures,
the music-video production,
and eventually the lyrics.
One K-pop newcomer described Stray Kids as pushing the boundaries of what they thought K-pop could sound like.
Another fan said they had previously thought K-pop simply wasn’t for them, but Stray Kids’ unique style and production changed their mind.
That’s an important distinction.
Felix can create curiosity. Stray Kids has to convert that curiosity into fandom.
Even within the fandom, some fans push back against giving the Felix Effect all the credit for the success of “God’s Menu.” They point to the song’s rap, choreography, production, beat changes and other members as equally important parts of what made the track memorable.
That’s probably the better way to understand it.
The Felix Effect is an entrance—not the entire building.
Why the Felix Effect Is So Valuable to Stray Kids
Every group needs something memorable.
But memorability becomes especially valuable when someone encounters a group for the first time.
Eight unfamiliar faces can be difficult for a newcomer to remember.
A completely unfamiliar Korean song can disappear among thousands of recommendations.
But an unexpected voice creates a reference point.
“The guy with the deep voice.”
Now the viewer has something to remember.
Later, Felix becomes Felix.
Then Changbin becomes Changbin.
Han becomes Han.
Bang Chan becomes Bang Chan.
And eventually eight strangers become Stray Kids.
That may be the real power of the Felix Effect.
It isn’t simply that Felix has one of K-pop’s most recognizable deep voices.
It’s that his voice gives people who know nothing about Stray Kids a reason to ask the first question.
“Who is that?”
And sometimes, that one question is all it takes to create a new STAY.