Depends on venue. I use a 20" kick, generally 90% i use nothing. If i do want to dampen i use a flat towel rolloed up and just touching heads (tuning tip from Drumset Tuning by Tony R Adams excellent book).
I also have ported head 4 1/2 around 4 o'clock,
Evans patch on beater head and loose tuning to give a fat sound.
Best way to tell, is go out front and have a listen.
If you want dead stuff it with pillows, if you want cardboard box sound remove front head, nice projection and tone no dampening and tuned heads.