One good thing about them is you do not need to do any sound deadening as they come in enclosed cocoon-like boxes.
I am not really sure about this. Actually the speaker are mounted to the original mounts in the inner metal door frame. Vibrations from the mount will still travel through the metal frame and also couple to the outer door cover. Dampening doors will help reducing those vibrations.
Also the speaker is not directly attached to the inner plastic cover. So vibrations will also be spread there inside the door. So sound deadening will still be beneficial.
However as shown in the video the vibrations traveling directly from the rear of the speakers to the outer door cover will be reduced. Therefore the noise level as heard from outside the vehicle might be lower. This does not mean that the (unwanted) vibrations especially on the inner metal frame are completely eliminated by this type of speakers.
