Summary

Work in progress - more insert types will be added, wall-friendly baseplate to follow.

These Gridfinity inserts were made as a way to ad hoc add or subtract surface area in your critical listening environment. Write-up to follow: EmiRizzi.com/blog .

In a critical listening environment, "strong dips and peaks [in frequency response] should be avoided" (The effect of a mixing console on the monitoring response in a mixing room, 2004)
"additional elements generally lead to positive effects in flatness of frequency response and spatial uniformity" (Acoustical effects of columns, beams and furniture on sound fields in small enclosures, 2010)

My 4x4 Base model is a modified version of Zakk Freeman's original (link below) “weighted base” model to reduce print time, weight, offset from wall, without going with the vertically instable skeleton-style outline baseplate models.
(Original model https://thangs.com/designer/ZackFreedman/3d-model/Gridfinity%20Baseplates-60925?manualModelView=true&utm_source=youtube&utm_medium=video&utm_campaign=zack_f)