static void eqwin_volume_set_knob (void)
{
    gint pos = hslider_get_pos (equalizerwin_volume);

    gint x;
    if (pos < 32)
        x = 1;
    else if (pos < 63)
        x = 4;
    else
        x = 7;

    hslider_set_knob (equalizerwin_volume, x, 30, x, 30);
}
static void eqwin_balance_set_knob (void)
{
    gint pos = hslider_get_pos (equalizerwin_balance);

    gint x;
    if (pos < 13)
        x = 11;
    else if (pos < 26)
        x = 14;
    else
        x = 17;

    hslider_set_knob (equalizerwin_balance, x, 30, x, 30);
}