Hot iMac due to high power speakers?

Hi folks,

I recently purchase a Corsair SP2500 speaker system for my mid-2011 i5 iMac and since then I notice that it has been running quite warm. CPU heatsink reads around 115-120 degrees F. I do have the iMac's output volume at max because I like my music loud. Can this put a lot of stress on the soundcard/DAC causing it to run warm? Also, will running a external DAC such as Audioengine D1 help reduce the temperture (because it's doing all the conversion, right?) and still be able to play music as loud as my wife can stand?

Thanks