SDL_Audiospec

hi!
how does SDL determine the size field in SDL_Audiospec structure?
In SDL docs I found that it should be related to the samples field.
Is size = samples multiplied by 2 (16 bits) multiplied by 2 (stereo) ?
I set samples to 1024, format to AUDIO_S16LSB, freq to 48000,
channels to 2, BUT obtained size of audio buffer is 16384.
Shouldn’t it be 4096?
Luigi Giancristofaro