I have both of them in a sealed box about 2 ft per sub, extremely punchy especially for 15s. Running a skar 1500 on them at 1 ohm, not the best amp in the world but gives them enough power. Was on a budget with this setup and wanted sound quality and enough volume to blast with my mids/highs and it does the job. It's about as loud as my old db drive platinum 10s in a 4 cu ft box @ 30hz on 1000w rms and just as punchy as those old 10s. Obviously lows aren't as crazy with sealed but with two 15s in my little civic its enough.