C++ BASS library custom frequency, custom timespan

Question

i realy dont know what is wrong with this code.

#include "bass.h"

int main() {
    BASS_Init(-1, 20000, BASS_DEVICE_8BITS, 0, NULL);
    BASS_SetVolume(1.0);
    HSAMPLE my_sample = BASS_SampleCreate(1000, 20000, 1, 1,
        BASS_SAMPLE_8BITS);
    HCHANNEL my_chann = BASS_SampleGetChannel(my_sample, true);
    BASS_ChannelPlay(my_chann, false);
    BASS_Start();
    return 0;
}

I want to play freq 20000 Hz through 1 sec, but i dont hear any sound. I dont get any error, from compiler and from BASS_ErrorGetCode(). I compiling on Windows 7, with lastest MinGW and BASS(lib, dll, h). When i try to play sample sach as .wav its working fine, but i want to manipulate freq and timespan. If there is way to use Stream and "pushes" struct as (timespan, freq) i would be blissful.