I agree with the "bad idea".
I have tried it mulitple times over the years, and agree with Knownothing.
Speakers are designed for a purpose, either ported or sealed.
You really won't get the both of best worlds in home audio anyway (alot of full range car speakers are infinite baffle designs and work good ported or sealed).
When I tried stuffing the ports in the past, I gained nothing, and lost alot as far as soundstaging, and bass goes.
Nothing wrong with ported speakers provided they are set up in your room properly.
If you have problems with ported designs, its either that your room has problems, the position of the speakers, or the port is in the front and you are listening near field.
I am a sealed speaker man myself (I (insert heart here)) love my NHT M6's, provided there is good amplication available.
Nothing at all wrong with ported speakers, just experiment to find the best placement.
I have a feeling thats the only problem with your speakers.