The EQ registers are grouped into groups of three to form 24-bit values representing EQ bands. The three registers must be written consecutively for the value to take effect, otherwise the written value(s) will be discarded. The three registers can either be written in a single I2C transaction or multiple, as long as no other registers are addressed in between.
Example 1: writing EQ Band 1 in one I2C transaction
S | Slave Address [W] + ACK | Register Address [0x46] + ACK | B0_1[23-16] + ACK | B0_1[15-8] + ACK | B0_1[7:0] + ACK | P
Example 2: writing EQ Band 1 in multiple I2C transactions
S | Slave Address [W] + ACK | Register Address [0x46] + ACK | B0_1[23-16] + ACK | P
S | Slave Address [W] + ACK | Register Address [0x47] + ACK | B0_1[15-8] + ACK | P
S | Slave Address [W] + ACK | Register Address [0x48] + ACK | B0_1[7-0] + ACK | P
You can check that the EQ band was successfully set by listening for the audible change or by reading the register back. Note that the EQ registers can only be read when the part is in shutdown mode.