Solid surfaces like MDF vibrate and cause an effective amplification of sound, particularly in the low frequency range.
It's not uncommon for people to make speaker enclosures out of MDF for this reason.
OnePlus 5T review: Hands-on
Illustrator Andrés Lozano on his improv line work, brazen use of colours & hand sketching
iPhone X review
Comment envoyer gratuitement des gros fichiers ?