just installed my FI Q 15 tonight.
its a very nice sub. it hits hard, and is very accurate. i have it in a 4 cub ft box with aeroports tuned to about 32htz. hits the lows very well. loud sq for a good price, FI Q 15. any questions pm me.
i hope to add more as i play it more. this was just a first impression review as i drove to wendy's and back.