I'm having to "up my ante" in the volume department. I'm used to polite society gigs and jazz gigs, but now I'm playing for someone who keeps asking for more volume and punch from my bass. Small and medium sized cabs used to always do the trick for me, but now I'm about to buy a loud 4 x 10. (I won't get into brand names right now.) I'll be driving it with a GB Shuttle 9.0 -- 500W/8ohms; 900W/4ohms. The 4 x 10 is rated for 800 watts, in 4 or 8 ohm versions. I'm aware that it requires 10 times the power to double the perceived loudness. So yes, the difference between feeding the 2 versions of the cab -- 500watts at 8ohms or 800-to-900 at 4ohms -- is not very significant. But my instinct is still to order the 4 ohm, and have more than enough power to extract the maximum SPL out of it, if/when necessary. (E.g., huge room or outdoors with limited/no PA subs -- hey, it could come up.) Btw, I'm not worried about overpowering the cab; I use my ears before I turn up the Master. However, the store has the 8ohm in stock; getting the 4ohm would take a while. Aside from the instant availability, the other argument for going for the 8ohm is that in the future I could add a second cab, if I needed another 3db of volume. Frankly though, for my modest level of career, at the moment it's hard for me to imagine ever needing the second cab. Anyway: Any opinions? 8 ohm version now, limiting me to 500watts, or wait for the 4 ohm -- limiting me to the one cab in the future? Thanks in advance.