ADAU1452 Coeff Calc IIR block gain is 1/2

Hi, I am using the IIR EQ block that uses the inbuilt coeff calc generation. Where the parameters are entered as Gain Q and Freq. Rather than the standard 5 coeff's

The Simulation Probe indicates that when I set the Boost to 5 that the response gain is 5db at the nominated Freq

However When I set the Boost21_ (0x162b) to 5 using Micro controller. I get exactly 1/2 (2.5db) actually measured Boost.

I performed a readback of this address and it is being set to 5.

Thoughts?

Thanks

Audio Signal Processors

adau1452

SigmaDSP Audio Processors