Can i disconnect the cavity bass driver from Kef 104/2?

Beside room acoustics, another solution is the obvious one, maybe different gear?

As already suggested, put a plug in the port. If you want to try the quick and easy test, just double up a pair of socks into a ball and stuff it in the port. Be careful not to push the plug all the way into the port and have it fall inside of the speaker. If you like the sound with the sock-plug, go out and get some nice foam and make a better fitting plug.

Just move the speakers and MLP around to see if it is due to room acoustics.

I placed the foam inside the bass hole as you guys recommended, i felt a lot better now. Thanks all.

I looked up the KEF on Bing and saw a picture of bi-wire speaker connections. If yours has two pairs of speakers posts, hook up only one pair (remove any jumper strips present) to speaker wire and see (hear) which drivers are still active. My guess is that the woofers are one set and everything else is the other set. Foam in the bass port is another option.