If you have EQ and can take meaningful measurements then yes, you can go sealed and still get deep bass. Thats something I have done. But you need a woofer with good thermal power handling (so the voice coil doesn't burn out) and a load of power.
The woofer can go as deep and loud in a sealed box as a ported one, provided the voice coil and the amps can deal with the power required to do so.