A commercial trap often has something hard and reflective in front, like a slotted / perforated plate, so it doesn't kill the high end as rapidly, this is ignored in the model. Also, an angled panel ...

The GiK Tri-Traps will improve the sound in your room. Ask any acoustical expert and you'll find that corner bass trapping is high up on their list of "first steps to a better sounding room." I've ...