Once upon a time .. long .. long ago .. I made some custom speaker pods for my 350Z.
Sometime in the past one of the woofers died. Yesterday, I went looking for a replacement.
The original woofers were Rockford Fosgate P28S8 – 8″ Punch Stage-2 (8 ohm) subwoofers. These were chosen as I could tuck them away nicely in a space on either side of the rear strut and not lose any ‘trunk’ space.
The choice of these speakers was in parallel with the choice of amplifiers. I used a Profile CA600M amplifier to power the subs. The CA600M RMS Power @ 4 Ohms is 1x300W (bridged). The Punch Stage 2 subwoofer is rated at 200 watts RMS/400 watts peak as stated above so fits nicely within the CA600M RMS of 1x300W bridged (150W per speaker). I chose 8 ohm speakers so hooked in parallel so the amp shows a 4 ohm load.
This was years ago and I found a Rockford Fosgate P2D4-8. Everything looked good until I looked at the dimensions. This speaker has a mounting dia of 8.72″ with a bolt hole dia in that mounting plate of 8.03″ .. and finally a trim ring dia of 8.96″. The problem is .. my pods have the speaker/trim ring recessed .. and that older woofer’s recess is 8.375″ dia.