For all you "USE THE SEARCH BUTTON" people I did and read through about 4 big threads on the sm-500. I still have some questions. I have a SWR Bass 350 and like the basic SWR sound, but I am hoping for more EQ flexibility. Anyone use the SM-500 with Aguilar GS-112s (two)?? Will the tone sound better than the 350 flat? How loud is the fan? is it variable speed (sensor controlled)? From the SWR SM-500 manual: Minimum impedance in the Stereo mode is 2 ohms per side. This means that you can connect: One 2 ohm speaker enclosure per side Two 4 ohm speaker enclosures per side Four 8 ohm speaker enclosures per side Minimum impedance in the Bridge/Mono mode is 4 ohms. This means that you can connect: One 4 ohm speaker to the Bridge/Mono output Two 8 ohm speaker enclosures to the Bridge/Mono output Four 16 ohm speaker enclosures to the Bridge/Mono output COOL!!!