impedance switch on amp

[bluesfloyd]

hi guys,
my amp head as a impedance switch that reads 4/8/16 ohms, i have a cab holding one speaker that say's 16 ohms on the speaker, i guess i set the amp impedance to 16 ohms yes/no ?

if i had a cab that held two speakers, both with 16 ohms printed on each speakers, would i still set the amp impedance to 16 ohms yes/no ?

thanks for your time guys,
bluesfloyd.

 

[jeremy]

Re: impedance switch on amp

one 16 ohm speaker = 16 ohm setting
two 16 ohms speakers in parallel = 8 ohm setting

 

[bluesfloyd]

Re: impedance switch on amp

hi jeremy,
thanks for your reply,
if i did play/use ONE speaker and the wrong impedance was set, lets say, amp impedance setting 4 ohms and the speaker 16 ohms, or amp setting at 16 ohms using a 8 ohm speaker, would that cause damage to the speaker or amp, yes/no? or just poor sound quality ?

thanks,
bluesfloyd.

 

[ehdwuld]

Re: impedance switch on amp

1x16 ohm = 16 ohm
2x8 ohm in series = 16 ohm
2x8 ohm in parallel = 4 ohm
2x16 ohm in parallel = 8 ohm

 

[jeremy]

Re: impedance switch on amp

hi jeremy,
thanks for your reply,
if i did play/use ONE speaker and the wrong impedance was set, lets say, amp impedance setting 4 ohms and the speaker 16 ohms, or amp setting at 16 ohms using a 8 ohm speaker, would that cause damage to the speaker or amp, yes/no? or just poor sound quality ?

thanks,
bluesfloyd.

depends on the amp. the speaker load is balanced through the output transformer to the tubes. a well build amp will usually take a 100% mismatch with out putting up much fuss (ie 16 ohm setting with an 8 ohm speaker, or 8 ohm setting with a 16 or 4 ohm speaker) but your tone, volume, clarity, and response will probably not be as good as it would be at the proper setting. going more than that, ie 16 ohm setting with a 4 ohm speaker is asking for trouble and probably wont sound all that great. plenty of people have done it and nothing blew up but its sure not recommended. in general it is best for the amp, tubes, and tone to match things properly. you could actually hurt your amp with a mismatch and a less robust amp is much more likely to suffer damage than an overbuilt one.