I had always been wondering about what kind of speaker are included in the Spider V series amps, and I was surprised there was little info available on the internet.   I was very curious what the sound of the amp might be like with the back panel off.  I really like playing my Spider IV with no rear panel, as well as with a lot of my other amplifiers.  I decided to take a look.     The speakers have pretty small magnets for a "120 watt" speaker - I don't think they would put out much SPL.  I