If memory serves me correct, porting of bass drum heads was initially intended to allow microphones inside the bass shell when drummers changed from the 1970s and went back to using a resonant head. In the 1970s most drummers would remove all of the resonant heads and play with only batter heads. The other thing we did not have in the 70s was multiple layered outer rings on the bass drum head (we used felt). Therefore, bass ring control was accomplished with a pillow or a blanket. Since I started using heads with multi layer bands on the outer edges, I no longer use a pillow or blanket.. I have seen many drum kits with a pillow or blanket stuffed inside where the blanket or pillow was molding... Yuck... Another reason I don't use them any longer. I figure if your going to over choke the Bass drum to get it to sound like a Cajon or a shoe box... then just replace it with a Cajon or a shoe box and be done with it...Bass reso:
Ported=Not so much
What do you guys like?
Not talking about miking, strictly the sound!
I'm currently using non-ported!
Therefore relative to live play, without microphones a port in the bass drum serves little purpose.
Its only when microphones come into play that the port finds its functionality.
I used to keep two heads one with and one without the port in the resonant head... then I stopped playing big venues and no longer had need for the port... My 22in bass is plenty loud for any venues I might play in today.... Of course during the pandemic we were not allowed to play to crowds...