I have a Carvin 1x15 with a 600-watt 4-ohm speaker, which I'm powering with a 1000-watt Carvin amp. I really like the cabinet and the speaker is OK, but it seems inefficient to me. I play mostly reggae, and I need serious bottom end. I'm considering changing speakers, and I wonder if anyone has suggestions on a powerful speaker with good bottom end. I think I'd rather stay with 4-ohms, because I can use the full output of my amp (BTW, while I like my Carvin equipment, I think the 1000-watt rating is liberal....). JBL's are great, but expensive.