Acoustics improvement of a room with riddled furniture [integrated bass traps]

Recently I renovated a room


Right now it is almost empty and has flat surfaces and has no carpets and other materials that can absorb the sounds. As a result of that I have a profound echo- it even took my brain a few weeks to apparently adjust to this new acoustic setting, as I discovered that sometimes I could not understand some words in my native language in played speeches. Soon I will be ordering production of furniture- for security and aesthetics reason it all surfaces will be entirely flat; and on top of that there still will be no carpet in the room. As a mater of fact I predict worsening of the acoustics

I know there are various bass traps, in form of foams and hard surfaces with holes. So I though to myself: why not cut such holes in some panels of my furniture, as I am already paying for cutting of the MDF boards?

And so: does anyone have access to files containing such holes. A ready to use shapes in form of curves?

Perhaps you turn to this institute:

https://www.nagata-i.com/

to get sound (!) advice.