private void do_downmix()
{
for (int sb = 0; sb < SSLIMIT; sb++)
{
for (int ss = 0; ss < SSLIMIT; ss += 3)
{
lr[0][sb][ss] = (lr[0][sb][ss] + lr[1][sb][ss]) * 0.5f;
lr[0][sb][ss + 1] = (lr[0][sb][ss + 1] + lr[1][sb][ss + 1]) * 0.5f;
lr[0][sb][ss + 2] = (lr[0][sb][ss + 2] + lr[1][sb][ss + 2]) * 0.5f;
}
}
}