I have a Lyric or an Anthem installed in three guitars. I still puzzle over the adjustments switch that, on the Anthem, adjusts the balance between under saddle PU and the contact mic and, on the Lyric, raises a broad range of high end freq's.

This adjustment seems more "relevant" to the venue, amp., or P.A. being used, rather than to the individual sound of the guitar.

Here's what I now think.: Put a sound-hole cover "in" or on your guitar when you adjust the screw. This minimizes the double sound you hear from the guitar itself and the speaker cone you are using as reference. In my experience, this reduces the bass freq.'s I hear in the process, resulting in a slight reduction in the amount of mic and/or the amount of high frequency augmentation.

Putting in the sound hole cover, listening, removing it, adjusting the screw, re-installing the sound hole cover..............is of course, tedious.

BTW: I make my own sound hole covers from wood. I make them in heart shapes. This serendipitously leaves an opening where the Lyric/Anthem volume control is.