# Ohms - power rating conversion?

Instruments and Gear
 Nutter166 18 May 2011 07:53 | Quote Joined: 22 Feb 2008Wales Licks: 2Karma: 14 Just looking for some help here, I'm trying to figure out the 8ohm power rating for power amplifier that only gives spec's for 4 and 2ohm power ratings. What I'm looking at gives 1250w@4ohms and 1500w@2ohms, however I'm running an 8ohm PA system. How do you convert the 4ohm power rating into 8ohms? And what would it be in this situation? Also since a rating for 8ohms isn't given does this mean the amplifier isn't capable of holding an 8ohm load (even though it is less demanding load compared to 4 and 2ohms)? Note: The PA system won't be running in series, this is direct one output to one input.
 gshredder2112 18 May 2011 10:24 | Quote Joined: 03 Sep 2010United States Licks: 3Karma: 22 well personally i havent a clue how to do it,but if you can figure this out your set. http://www.onlineconversion.com/ohms_law.htm \M/(*-+) gs2112
 DanielM 18 May 2011 11:04 | Quote Joined: 11 Apr 2011United Kingdom Lessons: 1Karma: 12 Well watts are power and ohms are resistance V=I/R and P=IV Therefore the watts it will give would be equivilant to P=RV^2 or power=resistance multipled by voltage squared. Although personally I'd treat anything you work out this with caution. Not because the equation is wrong but because I'm not 100% sure if this is the right context (AC vsDC power etc)
 Nutter166 19 May 2011 01:54 | Quote Joined: 22 Feb 2008Wales Licks: 2Karma: 14 Cheers for the response guys, I managed to see my uni lecturer about it and from my understanding i goes like this: all ratios referenced the power rating @4ohms. 8ohms = 100w = .5 4ohms = 200w = 1 2ohms = 400w = 2