I dunno but 50 watts may be on the low end. You could try to diy and and out a new woofer in but I would sugget buying a sub amp and a 10 or maybe even a pair. I have two car 10's with a 250 watt amp and star wars rocks. The first thing i would recomend if you want to change the 8 is measuring the air space to narrow the choices down. www.partsexpress.com or www.speakercity.com May have a subwoofer that fits in the air space.