# ohms vs. watts

Discussion in 'Amps and Cabs [BG]' started by spidersbass, Dec 8, 2004.

1. ### spidersbass

Nov 29, 2004
Downtown L.A.
okay, i know that when you connect 2 8ohm speakers in series, the impedence adds up to 16ohms... and when you connect those 2 speakers in parallel, the impedence halves into 4ohms.... question is, what happens to the wattage in both situations? do they also add up or what?

2. ### rusmannx

Jul 16, 2001
when ohms double, wattages is supposed to be half.
this isn't true though, because elcectronic components don't behave the same way math does. in theory though, if you you half the ohms, you would also double the wattage (assuming your voltage says constant).

Watts = Volts^2 / ohms

example: watts = 110volts^2 / 8ohms
watts = 1512.5

this time: watts = 110volts^2 / 4 ohms
watts = 3025

3025 happens to be 1512.5 * 2.

3. ### spidersbass

Nov 29, 2004
Downtown L.A.
cool, makes sense

so when ohms double, watts halve
and when ohms halve, watts double

right?

4. ### Tim__x

Aug 13, 2002
Alberta, Canada
There's two different power ratings here, there's the power the amp will put out, generally twice the power for half the impedance (ohms), and there's the power rating of the cabs, either way the power rating of each individual cab stays the same, but since they share the current (fairly) equally the total power rating of the cabs together is twice that of them apart.

This is all assuming identical cabinets, in case one cabinet is rated lower than the other but has the same impedance, then the total power rating is equal to twice the rating of the lower rated cabinet.