I recently strapped 2 hifonics brz2400.1's to a dual 4 ohm sony explode 10 freeair and it slammed for almost 4 seconds.the copper coil litterally melted.I used 4 kinetic hc 2000's and a 640 amp power supply to ensure my amps were being fed.I wonder what I woulda hit on the spl meter for that 4 seconds lol.