I have no trouble getting my hands on Subwoofer amps that can be built in to a speaker to make it active. But I need something full range. It's actually for a keyboard player friend of mine. He hes requested it be around 500W and as light as possible. I've spotted this one, but it's only 250W. http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=300-797&DID=7 I've also spotted one from Powersoft but I'm too scared to ask how much it is:- http://www.powersoft.it/download/datasheet/DigiMod%20500-1000.PDF So I guess I'm looking for something in between. Any suggestions?