follow Alpine's recommendations for either sealed or ported, they both work very well with the rms power. I have two type R's in a sealed enclosure (needed the space), powered by a 1200 watt@1 ohm amp, and it sounds great. If I had the space though, I would go ported.

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2004 300M SPECIAL
Alpine CDA 9833
Alpine Pxa-h701
Alpine Rux-c701
Rockford fosgate p400-4
Rockford fosgate p4004
Hifonics BX 1205D
JBL c608 GTi
JBL p963
Infinity 2.5" center channel
Alpine type R 12"(2)
200 amp alternator
yellow top battery
0 awg power and ground (welding cable) 300 amp anl fuse
all active SQL set up with 2000 watts rms