Name:    Kalle
Email:   santos-kuenkel@tronet.de  
Subject: series or parallel? 
Thread:  57
Time:    Sat, 21 Apr 2001 18:16:37 UTC

Steve,


I think I was wrong with the impedance of the built-in speakers: Two 8 ohm speakers wired in series would have a total impedance of 16 ohms, if wired parallel total impedance is 4 ohms. Conclusion: The built-in speakers' impedance is 4 ohms each, total impedance is 8 ohms, which should be the standard setting of the switch. The 4 ohm setting is in fact only for external cabinets with 4 ohms - btw. the 'funny' thing you heard isn't funny at all ;-) ->to determine the total impedance of two parallel wired speakers you'll have to apply 1/Re = 1/R1 + 1/R2 -> with to parrallel wired 8 ohm speakers this will result in Re = 4 ohms, that's probably the reason for the switch's 4 ohm option...


However, speakers don't have a static impedance like resistors although both are measured in ohm. The impedance of a speaker specified by it's manufacturer is just an average value. Actually it depends on the dynamic signal coming from the transformer and usually covers a great deal of an impedance range... So here we are again: What's that mystic switch for ;-)))


Kalle



P.S.: This Message board is really great - I made it my start page...