I installed 2 sd-2 10d4's today in the recommended 1 c^3 sealed box in single cab. I'm pushing with hifonics brz 2400.1d at 1 ohm. They slam on decaf'd zips but barely make a sound on regular songs at the same volume. Why?
Some songs bass frequencies are recorded louder or softer than others. That's why I modify all my songs in Audacity by boosting the bass if they were not recorded at enough amplitude.