Anybody tried these (drumports)

i get that it probably focuses the sound somewhat but wouldn't that make half of the space within the drum redundant? what's the advantage over just having a hole on the resonant head?
 
I've never seen that one but have had drummers come in with the smaller kickports at the venue I used to work at, seemed to make the drum sound deeper and punchier.
 
Never seen this before.

Our drummer got a "Kick Port", which is an insert for the bassdrum which sort of tunnels in slightly. I mic'd it a few times for practice recordings and it's definitely weird. Sounds good in the room, but hard to get a good mic'd sound. Weird resonances....
 
Im using and liking the kick port, never seen this tho

Do you record with one? Our drummer has one...his port hole is about 4'o clock position. It seems to sound better in the room than it translates through the mic. I recall a strange high pitched feedback when trying to mic the inside of the drum. Used a Beta 52A and it HAD to be outside the drum to rid the annoying ringing. I forget the other mic we tried, but it was smaller diaphragm and it was realllly bad.
 
Never seen this before.

Our drummer got a "Kick Port", which is an insert for the bassdrum which sort of tunnels in slightly. I mic'd it a few times for practice recordings and it's definitely weird. Sounds good in the room, but hard to get a good mic'd sound. Weird resonances....

I'm glad I'm not the only one that thinks this.. I fucking HATE kick ports. It gives that 30hz thump but all sorts of weird shit going on in the 160-200 area