Originally Posted by cel4145
That's very interesting that temperature differences could result in that. Is it the air temperature that effects the way that the sound propagates through the air? Or is the temperature effecting the performance of the driver, amp, or mic?
I can't say for sure yet. My initial thought process was similar to your first comment...something about the sound wave interacting with different air density for example.
But the more I research this the more it seems the biggest variable *may* be the DUT(device under test). If this is the case the amplifier(and how it reacts to increasing temps) could be the primary variable.
Another variable may be the exact sequence of the measurements. If you run CEA-2010 first in 80 degrees....it may not show as big a variance than running CEA-2010 last(after the amplifier is very warm because of 30 minutes of max performance checks for example).
I still have a lot of work to do here before I can speak with any certainty though. The only thing I'm 100% confident in at the present IS there is often(if not always) 1-3dB variance when measuring cold versus hot weather. This seems to be consistent between Power Sound , Josh, and Ilkka too.
Also, here is one of the comments Ilkka made,
>>>This is the same subwoofer that was tested last fall, but since those results caused so many heated debates, I decided to test it again in case I had done some error. Fortunately it wasn't the case. In fact this second time showed a little bit worse performance regarding maximum output (2-3 dB). Since the calibration procedure was identical to the last time, I can't think of any other major influence than the weather. Last fall it was blistering cold (around 5 C) but this time it was very warm <<<
Power Sound Audio