Bass trap with barrier mat

I love the bass trap that Hugh and Paul described in this SOS article
I was in my 30s back then, Nelly Furtado was hot in the charts and I was blissfully unaware of what bass traps were. Good times.
The trap sounds still very sound to me (see what I did there!), but having to make it now, would there be any design improvements that the Dynamic Duo would have come with?
I was in my 30s back then, Nelly Furtado was hot in the charts and I was blissfully unaware of what bass traps were. Good times.
The trap sounds still very sound to me (see what I did there!), but having to make it now, would there be any design improvements that the Dynamic Duo would have come with?