If you're attempting to use ALC you have to enable it on the i2s stream writer: i2s_stream_cfg_t i2s_cfg = I2S_STREAM_CFG_DEFAULT(); i2s_cfg.use_alc = true; i2s_stream_writer = i2s_stream_init(&i2s_cfg); Then when you call it to set the volume. You need to make make sure you are setting the volume p...