What was found
AT 12,000 FT, CLIMBING, WE HEAR A WHISTLE COMING FROM EMERG. EXIT. WHEN WE CLIMBED TO 14,000 FT OUR CABIN ALT WAS 11,000 AND DELTA P WAS AT RECLINE. WE STOPPED CLIMBING AND STARTED DOWN TO 10,000. AFTER FLYING AT 10,000 FOR A SHORT TIME THE MEDICS HEARS A WOOSH OF AIR FROM THE MAIN DOOR AND THE PRESSURE PEGGED AT -7000 AND OURS POPPED HARD. WE DECLARED AN EMERGENCY AND DESCENDED TO 6000 AND WAS UNABLE TO MAINTAIN PRESSURE (-200 -700). FOUND EMERGENCY EXIT DOOR SEAT DE-TATCHED. SECURED DOOR SEAL WITH 1300L IAW KING AIR 90 SERIES MM 52-20-03. FOUND DOOR SEAL INFLATION CONNECTION LEAKED. SECURED CONNECTION AS REQUIRED IAW KING AIR 90 SERIES MM 52-10-13. PERFORMED AIRCRAFT RUN UP. NOTED NO AUDIBLE AIR LEAKS FROM CABIN AND AIRCRAFT PRESSURIZATION OPS CHECK.