audio low quality when multiple loads

[IVAN-QX]

I'm using ffpyplayer for kivy audio
there is a problem of loading more than sound, for example:

s1 = SoundLoader.load('m1.mp3')
s2 = SoundLoader.load(m2.mp3')

if i played s2 it play at low quality sound but if i played s1 it will play fine
if the code swapped:

s2 = SoundLoader.load('m2.mp3')
s1 = SoundLoader.load(m1.mp3')

then s1 will play at low quality, s2 will be normal
loading just one sound at following has no issues

[IVAN-QX]

i discovered something
when s1 loaded before and i played s2
the point is that s1 loaded before will play stereo sound (2 channels)
while s2 will play mono sound (1 channel)
i think when the first sound load it will take 2 channels but second sound will take only 1
is that means there's only 3 channels has set ?
also even if i loaded s1 firstly and played just s2, s2 will be play mono sound
the issue not exist on audio_sdl2 with 2 sounds cause it has 4 channels, i set that on kivy cfg file