Thanks... No surface treatment yet.

Our dining table + coffee table (same room) is also in oak.

I usually sand them and treat them with soap (without pigmentation).

My plan is to do the same with these slats.

I am currently printing the first prototype. My speakers are black/black and my plan is to leave the original fret on the speakers and mount the slats on top. 

very nice project, looks fantastic.But irritating question:

could artificially added lamellas have bad influence on sound presentation of speakers, which were not designed to have them?

My plan keeping the original cover beneath the slats did not turn out very well. I changed the approach. The 3D printed part 'snaps' around the edge of the speaker and into the metal clip holding the original cover in place.

No glue, no screws ...

I do not notice any sound difference... but there is surely someone out there with a more 'educated' answer ... 😁

Lovely job. Top class work. I’m currently modifying my Beolab 1 tower speakers. I wanted to do the same thing that your doing with your grills, but instead of using wooden fins, I was going to have chrome metal fins. Any chance you could help me create the 3D printed plastic brackets for my speakers?

Here are my current Beolab 1 mods (not finished yet)