When to ad eq and bass boost??

[Tinkertoy]

The directions for the dd1 indicate to turn off all eq bass boost loudness etc when calibrating for distortion. When do we apply these settings? If they are applied after the gain is set don’t we risk clipping? 

[Dafaseles]

Yes. The goal is to not use those settings at. But if you wish to use them, before finding the max volume of your head unit and setting the gain, turn them up. Then after you set the gain, you can keep them where they're at or turn them down. You never add to the frequency, you only cut or, like you said, you'd add clipping